Audit Handbook 01-Dec-09 Doc Mc

Heat Treating Task Group

Audit Handbook

Released:

December 01, 2009

PERFORMANCE REVIEW INSTITUTE

161 THORN HILL ROAD

WARRENDALE, PA 15086-7527

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

HEAT TREATING TASK GROUP ... 1 

Released: ... 1 

A. FOREWORD ... 3 

B. DEFINITIONS ... 4 

C. AUDITING TO NADCAP AUDIT CRITERIA ... 9 

C.1  SPECIFICATION ADHERENCE ... 9 

C.2  AUDITOR GENERAL GUIDELINES ... 13 

C.3  SUPPLIER GUIDELINES ... 14 

C.4  GUIDELINES FOR TIME MANAGEMENT OF THE AUDIT ... 15 

C.5  VERIFICATION OF CORRECTIVE ACTION (VCA)AUDITS ... 16 

C.6  SNAPSHOT AUDITS DEFINITION ... 16 

C.7  SATELLITE AUDITS ... 16 

C.8  SPEC CANCELLATIONS &SUPERCESSION ... 18 

C.9  AC7102/S ... 18 

D. QUALITY SYSTEMS ... 19 

D.1  TRAINING ... 19 

D.2  ELECTRONIC PROGRAM CONTROL AND DATA ACQUISITION ... 19 

E.  GENERAL HEAT TREATMENT ITEMS AND STEELS (AC7102) ... 20 

E.1  TEST AND INSPECTION ... 20 

E1.1  Room Temperature Tensile Testing ... 20 

E1.1.1  Sub – Contract Machining of RTT Test Pieces ... 20 

E1.2  Round Robin Programs for Metallography and Microhardness ... 21 

E1.3  Surface Contamination Testing ... 22 

E1.4  IGA/IGO Evaluation ... 22 

E1.5  Hardness Testing (AC7102/5 Rev. NA) ... 22 

E.2  FURNACE DOCUMENT CONTROL ... 23 

E.3  CONTROL OF HEATING ENVIRONMENT ... 23 

E3.1  Hi-Limit Instruments ... 23 

E.4  QUENCH SYSTEMS ... 23 

E.5  VACUUM CONSIDERATIONS ... 24 

E.6  RACKING ... 25 

E.7  RE-HEAT TREATMENT ... 25 

F.  PYROMETRY AUDIT INTERPETATION ... 25 

G.  JOB AUDITS... 26 

G.1  JOB SELECTION ... 26 

G.2  AUDITING NOTES FOR JOB AUDITS ... 27 

H.  BRAZING ... 28 

H.1  CONSIDERATIONS ... 28 

I.  ALUMINUM HEAT TREATING ... 29 

I.1CONSIDERATIONS ... 29 

I.2  REFRIGERATION CONSIDERATION ... 29 

I.3  CONDUCTIVITY TESTING ... 29 

APPENDIX A: ALUMINUM SPECIFICATIONS ... 30 

APPENDIX B: PRIME SPECIFICATION MATRIX ... 34 

APPENDIX C: AMS 2750 VS RPS 953 COMPARISON CHART ... 38 

APPENDIX D: AMS HEAT TREATING SPECIFICATION – START OF SOAK TIME RECOMMENDATIONS ... 39 

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

A. FOREWORD

This Auditor/Supplier Handbook has been prepared to assist the Heat Treating Auditors and Suppliers as follows:

• Where necessary, provide clarification on the intent and rationale of the Heat Treating Task Group as it pertains to specific questions contained in the current revision of AC7102 and its corresponding slash sheets, as well as heat treat specific issues with Materials Testing Laboratories (MTL) checklists commonly used during heat treating audits.

• Clarify the material to be reviewed in addressing audit questions • Standardize the audit from Auditor to Auditor

• Standardize definitions

• Provide general guidance on Task Group expectations as to the Supplier’s preparation for an audit and on an auditor’s execution of the audit

• Provide general information on unique requirements of participating prime contractors to aid the Auditor in determining supplier conformance to customer requirements

This handbook was prepared to directly reference the most current audit checklist revision. Sections are divided to correspond to audit criteria slash sheets. Current Heat Treating controlled checklists are: AC7102 Nadcap Audit Criteria for Heat Treating

AC7102/S Nadcap Supplemental Audit Criteria for Heat Treating (Primes specific requirements) AC7102/1 Nadcap Audit Criteria for Brazing

AC7102/2 Nadcap Audit Criteria for Aluminum Heat Treating AC7102/3 Nadcap Audit Criteria for Carburizing

AC7102/4 Nadcap Audit Criteria for Gas and/or Ion Nitriding

AC7102/5 Nadcap Audit Criteria for Hardness Testing for Heat Treating AC7110/1 Nadcap Audit Criteria for Brazing (Torch/Induction)

Additional checklists may be required during an audit (including AQS and/or MTL Task Group checklists). This handbook will not give guidance for questions based on other task group’s checklists; however, if an interpretation conflicts between Task Groups, the Task Group that controls the given checklist will be the governing body.

Note: Paragraph numbers in this document that do not begin with a letter correspond to the Audit Checklist question with the same paragraph number. Italicized text next to an audit checklist paragraph number is the text from that checklist question.

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AUDIT HANDBOOK

B. DEFINITIONS

NOTE: Many of the detailed requirements for the items defined below are found in the applicable specification. These definitions apply only if no customer requirements are specified.

Activation - A process by which the surface to be Nitrided is prepared by using various processes

(chemical/mechanical) so that the Nitriding process can proceed at a higher intensity, resulting in a harder surface with greater depth.

Control Thermocouple - A thermocouple installed within the furnace volume which is used to control the heat

input to the working zone.

Conversions from Fahrenheit [°F] into Celsius [°C] - When assessing Suppliers against customer

requirements which are expressed in degrees Celsius take a special note of conversions from degrees Fahrenheit in TUS, SAT, etc. Customer and governing specifications, especially of European origin, may have temperature tolerances which are less than the similar North American (e.g. AMS) material. For example, solution treatment of aluminium alloys is typical +/- 10 °F in AMS, but +/- 5°C(±9°F) in European standards.

North American standards for heat treatment may also have definitions which are not in line with the European Prime requirements (e.g. AMS-H-81200, clause 6.3.9 Metrication).

Example:

A European Prime requires an aluminium solution heat treat temperature of 475 °C +/- 5°C. In the case where the Supplier is working and calibrating in Fahrenheit they have to be within the +/- 5°C (±9°F) maximum allowable tolerance. If the furnace(s) are tested/certified to a uniformity of +/- 10 °F, this converts to +/- 5.6 °C and exceeds the required tolerance. This is a NCR.

Correction Factor – The number of degrees, determined from the most recent calibration that must be added

algebraically to, the temperature reading of a sensor, or an instrument, or a combination thereof

(system) to obtain true temperature. The correction factors of sensors and instruments are usually kept separately and added together algebraically when a combination is used (from AMS2750 Rev D). Your procedures must clearly state how you calculate and use correction factors.

Dead Band – The range within which the temperature input can be altered upscale and downscale without

registering a change on the instrumentation (from AMS2750 Rev D).

Heat Sink - A mass of material equivalent to the heat transfer characteristics of the thinnest section of the part

being heat treated. A thermocouple surrounded by the heat sink is expected to represent the

temperature of the limiting section thickness of the part. Heat sinks may be used during TUS per section 3.5.10.1 of AMS2750 Rev D.

Intergranular Oxidation/Intergranular Attack (IGO/IGA) – Per ASTM definitions.

Intermediate Temperature - A temperature that the part must be cooled to or below or heated to or above prior

to continuing the next sequence stage of the heat treat process

Leak Up Rate (leak rate) - A test in which the furnace chamber is evacuated, isolated from the evacuation

source, and the leakage determined within the system by observing the pressure rise per unit of time. NOTE: Leak up rate expressed in microns/hours. 1 micron is approximately = 1 X 10-3 torr = 0.001 mm Hg = 133 X 10-3 Pascal.

For example, when 1 micron is specified, 0.1 micron is a higher Vacuum or lower pressure.

Load Sensors – Sensors that are attached to the production material or a representation of the production

material, that supply temperature data of the production material to process instrumentation.

Long Job Audit – Audit of multi-step heat treat process on a job which has been completed (questions 10.1 and

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

Major Findings

–

The absence of, or systemic breakdown of, the Process Control and/or Quality Management

system and any non-conformance where the effect impacts or has the potential to impact the integrity of the product.

Heat Treating Task Group Examples - Any violation of engineering processing parameters either

required by customer-invoked specification or stated in Supplier’s planning, or a lack of documentation demonstrating compliance to it. Parameters may also include ones not stated in the examples below:

1. Atmosphere/vacuum levels

The Supplier's shop paper stated the use of Argon up to a pressure of 500 microns during a heat treatment. The Customer did not specify pressure, and it was not stated in other Supplier

documents. The actual pressure during the heat treatment could not be determined because the chart recorder was not configured to read pressures greater than 100 microns.

•

Why an NCR? Lack of documentation demonstrating compliance to the pressure stated in the Supplier’s planning.

2.

Inspection and Testing – Acceptance of (signing or stamping off) a process or test before that process or test has been completed.

The Supplier’s shop paper/job planning or test records indicate that a process or test has been accepted before that process or test has been fully completed.

• Why an NCR? Violation of fundamental Quality principles and Quality System requirements. Note: An isolated occurrence will result in a Major NCR. If these actions are determined to be systemic an additional Major NCR will be issued against the Supplier’s Quality System for allowing this practice or not detecting it, and a Supplier Advisory will be issued.

3. Pyrometry Testing -- Systemic violations or excessive extensions of testing intervals

The Supplier had no records of System Accuracy Testing for three furnaces.

•

Why an NCR? Systemic violation of customer and Nadcap-invoked requirements for periodic equipment testing.

4. Pyrometry Testing -- Incorrect application of correction factors resulting in an out-of-tolerance condition

The Supplier’s procedures did not clearly state the difference between error and correction factors. Evidence of incorrect application of these was found. This included a TUS test thermocouple Correction Factor at 700°C that was subtracted rather than added, incorrectly producing an acceptable result, and TUS reports that indicated that an instrument’s Correction Factors are declared and stated as being applied without being included in the calculations.

•

Why an NCR? Violation of the application of correction factors resulting in an out-of-tolerance condition.

5. Quenchant media, temperature or time

The Supplier’s planning did not state a quenchant oil temperature. The Customer invoked Specification required that initial quenchant oil temperature to be between 60°F and 160°F. The oil temperature at the start of quench was 150°F.

•

Why an NCR? Breakdown of the flow down of Customer requirements to Supplier’s planning.

6. Repeat Findings (Non-sustaining Corrective Action) from Last 2 Audits

The Supplier’s procedure required biannual evaluations of Heat Treating operators. The Supplier stated the evaluations had been done and recorded on a skill matrix, but no objective evidence of this was available. This is a Non-sustaining Corrective Action from the prior audit.

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

•

Why an NCR? Lack of documentation demonstrating compliance to the periodic evaluations for Heat Treating operators required by the Supplier’s procedure.

•

Major NCR because repeat finding from previous audits.

7. Temperatures and temperature tolerances.

The Supplier’s shop paper stated a tolerance of +/-25°F for a 775°F heat treatment. The Customer invoked Specification required a tolerance of +/-15°F. During the treatment, some recorded load thermocouple readings remained below 760°F.

•

Why an NCR? Breakdown of the flow down of Customer requirements to Supplier’s planning with a violation of the temperature requirements of the customer-invoked specification.

8. Testing Methods for Parts

The Supplier performed verification using a Vickers test block as recorded on a machine verification sheet for microhardness testing, but the machine was used to perform Knoop hardness testing using 200-gram force. The Supplier's procedure did not state the required internal weekly verification of the microhardness testing machine to the hardness testing scale being used. The Customer-invoked specification required that verification be done using the hardness scale that will be used for testing. The Supplier’s verification sheet provided no objective evidence that the machine has been verified using a Knoop test block.

•

Why an NCR? Lack of documentation demonstrating compliance to the testing method required by the Customer-invoked specification.

9. Times and time tolerances

The Supplier’s shop paper stated an allowed set temperature between 1750°F and 1850°F, and a 25 to 50 minutes soak time. The Customer did not specify the processing time or

temperature, and only specifies a hardness requirement. An 1800°F set point was selected and used. During the heat treatment, the load thermocouple was between 1750°F and 1775°F for 15 minutes.

•

Why an NCR? Violation of the time requirements stated in the Supplier’s planning.

Material Specification – Industry or Prime specification which defines the properties of the parts or raw

material.

Metal Temperature – When called out in a spec or procedure, mandates the use of load thermocouples unless

otherwise specified by the Prime.

Minor Finding – A non-systemic lapse in conformance to the Process Control and/or Quality Management

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

The Supplier’s procedure stated a provision to suspend equipment from use and to evaluate product impact following a TUS failure, but no actions were stated for an instrument calibration failure or SAT failure. No evidence of SAT or TUS failures were found. Correct actions were evident after instrument calibration failures.

•

Why an NCR? Inadequacy of a required procedure.

2 Pyrometry Testing -- Short, isolated extension of periodic testing intervals

The Supplier performed a SAT test monthly for a Class 2 Type B air furnace number 17 on two separate occasions. The Customer and Nadcap-invoked requirement was biweekly. All other records were conforming.

•

Why an NCR? Isolated extension of a periodic testing interval.

3 Pyrometry Testing -- Incorrect application of correction factors that does not result in an out-of-tolerance condition

The Supplier applied the correction factor based on the “as found” value to the SAT test instrument. The Customer-invoked specification required the correction factor based on the “as left” value to be used. The actual Correction Factor for the instrument was within 0.2°F, and was determined not to produce any unacceptable SAT results.

•

Why an NCR? Violation of the application of correction factors that does not result in an out-of tolerance condition.

NCR – Non-Conformance Report, findings during an audit that require the full five part response as outlined in

the Supplier’s guide.

Non-Automated Processes & Recordings – If cycle is operator controlled i.e. temp and time, software control

section in AC7004 is not required. AC7004 applies for those systems that only require an operator to enter a recipe number or for any part of the processfrom a sealed menu

Nonsustaining / Repeat Findings – Non-conformances that are generated as a result of not implementing

corrective actions from either ofthe 2 immediate previous audits or those where corrective actions may have been implemented but were determined to be ineffective.

Objective Evidence – Shall include, but may not be limited to: job travelers, furnace charts, various types of

logs and logbooks, training records, document change records, customer documents such as purchase orders, packing slips, etc., or a direct demonstration. Objective evidence is required to be submitted for all findings, regardless their designation.

Over-temperature Instrumentation – A sensor/instrument combination installed in the furnace, which is used to

monitor any over-temperature occurrence and generate an alarm and/or cut back or shut down the heat input. The purpose for this control is protect material and/or the furnace from overheating (from

AMS2750 Rev D.

Parts – (From AMS-H-6875, 6088, 81200, etc.) Usually identified by a part number, produced from raw material

in accordance with the requirements of a drawing, and are usually tested by nondestructive techniques only. They are heat treated, by or for a fabricator; in accordance with a drawing, purchase order, fabrication order, or heat treat specification. At the time of heat treatment, they may resemble raw material.

The Heat Treating Task Group further states: In the absence of other specific direction, material should be treated as a “part” if it has a specific Prime part number and if it is being supplied in either partial or full heat treatment to establish final properties (e.g., solution heat-treated).

Raw Material – (From AMS-H-6875, 6088, 81200, etc.) Usually includes, but is not limited to, such items as

sheet, plate, wire, rod, bar, forgings and extrusions. It is usually identified by a heat or lot number and is usually tested destructively for acceptance. It is heat treated, by or for a material producer, in

accordance with a material specification which may require, by reference, conformance to a heat treating specification.

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

study or measure of the reproducibility of results generated by the laboratory personnel using the laboratory procedures. The intent of the internal round robin is to address the reproducibility of the results by operators and equipment.

Slash Sheet – Audit criteria on a specific area that may be optional dependent on a supplier’s facilities. Slash

sheets are numbered on the base checklist as “AC7102/X”.

Soak Time – The amount of time required by specification, blueprint, purchase order for the furnace/parts to be

at set temperature, taking into account the furnace tolerance.

Short Job Audit – A single complete thermal cycle that should be in process during the audit.

Stabilization – (also referred to as equalization, equilibrium, steady state or soaked condition). Furnace

stabilization occurs when all control thermocouples are within the allowable TUS tolerance span and controllers are cycling and/or maintaining the desired temperature in each zone.

System Accuracy Check/Test (or Probe Check) (SAC/SAT) – An on-site comparison of the

instrument/leadwire/sensor readings or values, with the readings or values of a calibrated test

instrument/leadwire/sensor to determine if the measured temperature deviations are within applicable requirements. Performed to assure the accuracy of the furnace control and recorder system in each control zone. (from AMS2750 Rev D).

Systemic – Procedures, actions, or events that are not isolated, but found to be part of the Supplier’s system.

When multiple occurrences of the same violation are observed, it is termed as being systemic.

Temperature Uniformity – The temperature variation (usually expressed as +/- degrees) within the qualified

work zone with respect to the set point temperature. For retort furnaces where a sensor is used to control temperature, the temperature variation is with respect to the sensor in the retort and not to the furnace set temperature (from AMS2750 Rev D).

Temperature Uniformity Survey (TUS) – A test or series of tests where calibrated field test instrumentation and

sensors are used to measure temperature variation within the qualified work zone prior to and after thermal stabilization (from AMS2750 Rev D).

Vacuum Level – "Higher" or "better" vacuum means "lower" pressure. Required levels will usually be specified

by the drawing or material specification, and unless otherwise stated are maximum pressure levels. For conversion: 1 torr= 1mm Hg = 133 Pascal = 1x103 microns. For examples, when 1 micron is specified, 0.1 micron is a higher Vacuum or lower pressure.

Voided Nonconformance – A nonconformance generated as the result of a clear misunderstanding by the

Auditor and struck out as a “void”. Requires rationale for voiding and may require review by the Task Group or Staff Engineer. Number assigned should not be re-used.

Qualified Work Zone – The defined portion of a furnace volume where temperature variation conforms to the

required uniformity tolerance.

• All parts or material must be contained in this working zone. • Furnaces may have more than one zone

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

C. AUDITING TO NADCAP AUDIT CRITERIA

C.1 Specification Adherence

ƒ While the Heat Treating Task Group identifies industry specifications for use and guidance, Suppliers are not automatically allowed to default to those requirements. They are, automatically, to adhere to whatever their Customer requires of them. As a general reference, a matrix of Nadcap Mandating Primes and the specifications they generally require their Suppliers can be found at the end of this document in the Appendix.

ƒ Question: What is the Nadcap Auditor to do when during a job audit they find that the Supplier has a P/N frozen/ fixed planning process signed by the Prime Customer that deviates from the specification

referenced in the frozen/fixed planning?

Nadcap Primes

YES - The Auditor Should Raise an NCR Because My Company

Only Uses Frozen Planning to Guarantee

That The Referenced Specification is Properly Flowed. The

Supplier and Person Approving the Frozen

Planning Made An Error.

NO - The Auditor Should Not Raise An

NCR. My Company Uses the Frozen Planning Process to Authorize Deviations To The Specification Requirements. If The Frozen Process Is Approved/Signed By The Prime, No Further

Investigation Is Required.

N/A - My Company Does Not Utilize Frozen Planning or Processes. Airbus SAS X Remark: Supplier should have a Supplier-PFA(= Permit of Alternative) ,Deviation has to be approved and accepted

by customer, if not

than raise NCR

Alenia Aeronautica

Any Supplier can deviate from a specification using an approved PSD (Process Specification Deviation)

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

BAE Systems X

Bell Helicopter X

Boeing

"Heritage" Douglas (DPS) X

"Heritage" Boeing (BAC) X

"Heritage" McDonnell (PS) X

"Heritage" McDonnell

Helicopters (HP) X

"Heritage" Rockwell X - except SMPP

Bombardier Aerospace "Group Specifications". Montreal - Process

Specs ( MPS / BAPS ). X

de-Havilland - Process

Specs (PPS). X

Lear Jet - Process

Specs ( LES / P Specs ). X

Shorts - Process

Specs (P Specs ). X

Cessna Aircraft

Any Supplier can deviate from a specification using an

approved SDR (Specification Deviation

Request) -- Casting Suppilers can deviate if

listed on an approved Foundry Control Approval -- Forging Suppliers can deviate if

listed on an approved

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

Goodrich Aerostructures X

Hamilton Sundstrand X

Hawker Beechcraft X

Honeywell Aerospace X * see comment below

Liebherr-Aerospace X

Lockheed Martin

A NCR should be written for deviations of not following the frozen planning. It is not the

auditors place to assume an error was made. It is possible for the planning to contain a requirement that was

approved via an approved procedure.

Any Supplier can deviate from a specification using an

approved VRIC (Vendor Request for

Information and Change). There should be some kind of notification or follow up action by the supplier

to their customer.

MTU Aero Engines

X Remark: Supplier should have a SAPA (=Supplier Alternative Process Approval) , if

not than raise NCR

Northrop Grumman X

Parker Aerospace X

Rockwell Collins X

Rolls-Royce

X - But would request that Nadcap auditor advise the Prime to permit confirmation that

an error had not been

made.

SAFRAN Group

Aircelle

X - if the deviation is not formalised in a DEP

Demande d'Ecart Procédé (process deviation request) Messier-Bugatti, Microturbo, Snecma, Turboméca X

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

Sikorsky Aircraft X

Sonaca X(1)

Spirit Aerosystems

X(Boeing work which Spirit

has delegation to

freeze.) Not for Spirit Work.

Textron Aerospace X

Textron Lycoming Engines X

United Space Alliance

Ares

X - any deviations to specs will be identified on drawing or in a USA approved Request For

Information (RFI)

Orbiter - "Heritage"

Rockwell X - except SMPP

Solid Rocket Booster - "Heritage" Pratt & Whitney

(USBI)

X - any deviations to specs will be identified on drawing or in a USA approved Request For

Information (RFI)

Vought Aircraft X

(1) Deviations are approved by Sonaca only by use of RFA form (Request For Deviation).

*Honeywell Comment: The Prime should be notified so that they can investigate. If the problem turns out to be at the Prime’s end, then the NCR can be voided.

HEAT TREATING TASK GROUP

AUDIT HANDBOOK

ƒ Suppliers certify their work to a host of different documents. The requirements of many Customer specifications are different than AMS or MIL specs. Process certifications should only be to the specs followed.

ƒ If a checklist question requires something of a Supplier that is not in their Customer’s requirements, the Supplier must adhere to the checklist question. The checklist is considered to be the established requirements of any Prime mandating Nadcap accreditation. In other words, a checklist / Nadcap requirement is a Prime / Customer requirement.

C.2 Auditor General Guidelines

ƒ Heat Treating Auditors shall comply with the general requirements for completion of the checklist contained in the core Nadcap Auditor Handbook. These requirements include, but are not limited to, the information in this table.

Table I Checklist Guidelines

All NAs shall be explained with supporting remarks Yes

NCRs may be voided on-site by the Auditor; Supplier need not answer Yes

All questions must be answered Yes

All paragraphs involving an NCR must be referenced on the NCR Yes

Auditor to validate NCR's from the previous audit; Result of this validation is reported in the cover letter

Yes ƒ For Initial audits, the auditor shall visit all attended shifts when feasible.

ƒ For Reaccreditation audits, the auditor should visit all attended shifts when feasible.

ƒ In addition to the general Auditor requirements for completion of the checklist, Heat Treating Auditors shall comply with the following:

a. Abbreviations shall not be used unless explained in the cover letter attached to the audit.

b. The use of acronyms shall be limited to commonly accepted and understood acronyms (i.e., FAA,

DoD, etc.)

ƒ Writing NCRs:

a. Be sure to always have checklist question and reference number.

b. The finding must be a checklist nonconformance, a specification non-conformance , or a Prime requirement non conformance, not an opinion, not a best practice criticism,

c. Don’t combine different findings because they appear on the same job unless RCCA are the same. d. Be aware of the requirements for classification of Major Findings, Minor Findings, and

Nonsustaining/Repeat Findings.

e. When an NCR is issued against a checklist question and it is determined that the NCR is a nonsustaining corrective action, DO NOT issue an extra NCR against Chapter 3 (General Quality System) in AC7102, but link the issued NCR with the correspondent question in Chapter 3 of AC7102. f. When one (1) NCR is issued against checklist questions and it is determined that the NCR is a nonsustaining corrective action, DO NOT issue an extra NCR against Chapter 3 (General Quality System) in AC7102, but link the issued NCR with the corresponding question in Chapter 3 of AC7102. g. When two (2) NCRs are issued against checklist questions and it is determined that both NCRs are nonsustaining corrective actions, ISSUE an extra Major NCR against Chapter 3 (General Quality System) in AC7102.

h. Review the guidelines for acceptance of NCRs on site. ƒ Voiding, and Accepting On-site NCRs:

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AUDIT HANDBOOK

a. If an Auditor initiates a NCR and then the Supplier provides additional information that proves that the NCR in fact does not exist, then the Auditor can void the NCR. Reason for voiding the NCR must be documented by the Auditor letter. Do not assign the same NCR number.

b. On-Site Acceptance of Non-conformances by Auditors: The nonconformance must meet the definition of a Minor finding, be of the nature of a paperwork oversight or administrative issue, and be

properly corrected and closed out within the audit period. It must still be reported to the Task Group and include appropriate documentation of closure. Inclusion of root cause analysis is required when appropriate. Staff Engineers or Task Group members have the option to reopen the NCR and request additional information or action.

ƒ When an NCR is written and noted as having an escape and/or Supplier to Evaluate Product on hardware, the following is required:

• Need to review other jobs to determine if it is an isolated case. • Need to review other jobs for potential product impact

• Supplier must notify the direct Customer of the discrepancy in writing. • The notification must include:

ƒ What the nonconformance consisted of ƒ A request of your customer to notify the Prime

ƒ A request for written acknowledgement of the receipt of the Product Impact/Potential Product Impact notification

ƒ

Attach a copy of supplier’s written “Notification to Customer” and the “Acknowledgement” from

your customer into the applicable NCR in your audit report in eAuditNet

C.3 Supplier Guidelines

ƒ Para 1.0 of AC7102 covers specific instructions for Suppliers to be audited. While many items in this section are not requirements, it is in the best interest of the Supplier to perform all duties properly to avoid delays during or after the audit.

ƒ It is mandatory to perform a self-audit per 1.1.1 of AC7102 and have all corrective actions implemented prior to the Nadcap audit. Auditors have been directed to write an NCR against a Supplier who does not perform a self audit to the required checklists. It is the experience of the Task Group that Suppliers who fail to perform the self-audit are more likely to fail the audit, receive a higher number of findings, and take longer to become accredited.

ƒ If upon review of the checklist before an audit, a Supplier has difficulty interpreting the checklist question, they shall attempt to perform the following:

a. Cross-reference that question with the corresponding section of this handbook for guidance b. Contact the Heat Treating Staff Engineer for clarification

c. Contact a Prime representative on the task group for clarification

Waiting to clarify a question with the Auditor may result in a NCR if corrective action was required. Knowingly waiting to correct a non-conformance until an audit is questionable quality practice.

ƒ Suppliers may obtain the current failure criteria from NOP-11 and NTGOP-001 Appendix 3.. This can be downloaded from “User Documents” in eAuditNet.

ƒ On the last day of an audit, the Auditor should direct the Supplier to Supplier’s Guide in eAuditNet as an aid for their responses to findings. The Supplier shall follow the proper response format stated in eAuditNet Supplier Guide in order to keep the review times as short as possible. The link to this guide is listed in the Supplier Response Guidelines posted in NCR 1 of their audit findings. It will also be advisable for the Supplier to review the tutorial on RCCA (Root Cause Corrective Action) on the PRI website.

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AUDIT HANDBOOK

C.4 Guidelines for Time Management of the Audit

ƒ Time management of the audit is absolutely essential. The basic purpose of the Nadcap audit is four fold. a. Accurate identification of the Customer requirements

b. Careful determination that the Customer requirements are flowed down to shop paperwork and any sub-tier Suppliers.

c. Verification that the Heat Treater and other shop personnel (cleaning, inspection, test personnel)have correctly implemented and documented the heat treating requirements required by the Customer. d. Assure there is an effective quality assurance system functioning within the heat treating department. ƒ Heat Treat Task Group time management recommendations for Auditors are to ensure the purposes of an

audit are maintained.

ƒ Auditors should arrive at the facility on the first day early enough to put a strong first day in, but allow time for the company to get organized, especially on a Monday. If possible, the Auditor should arrive about one half hour after the Quality Manager or Supplier point of contact arrives. Try not to inconvenience Supplier and work within their designated work times.

ƒ Auditor and Supplier representatives should jointly plan the audit, this point is especially important in larger facilities. It is recommended that the audit should be performed in the following order:

a. Brief tour of the facility b. Job Audits

c. Pyrometry

d. Material Testing (Hardness, Tensile, etc.)

e. Validation of Previous NCRs (reaccreditation audits only) f. Additional areas as necessary

ƒ The Supplier and Auditor should settle issues of proprietary information, trade secrets, non-disclosure agreements and intellectual property early in the audit process (preferably prior to the on-site audit). ƒ A brief tour is usually in order at the beginning of the audit. In captive shops only a review of the heat

treating area is necessary. During the tour, the Supplier and Auditor should try to identify any parts that may qualify for an in-process job audit. All or at least half of the job audits should be selected during the first morning. Supplier supervision should assist in scheduling heat treatments while Auditors are at the facility. This is also an opportunity to review calibration stickers on the equipment.

ƒ Perform the job audits and take the time to verify that Customer requirements are identified. Both short job and long job audits should be completed by the end of the second day or least by mid-day of third day of auditing for regular audits. Reference Appendix D, pages 33 – 37.

ƒ It is the best practice to complete the pyrometry section of AC7102 checklist while performing the job audits. This will speed up the audit by reviewing the SAT and TUS data for the furnaces from which you are performing job audits. The balance of the pyrometry section can be completed after all of the job audits have been performed.

ƒ Perform all Pyrometry auditing paying attention to correction factor, stabilization of the furnace, correct identification of the high and low temperatures the number of surveys per operating range and frequency of surveys. Arrange to witness a System Accuracy Test (SAT).

ƒ Each potential NCR identified at the time of the audit shall be mentioned to the Supplier.

ƒ A daily out-brief shall be performed at the end of each day so the Supplier knows the status of the audit on a daily basis.

ƒ Auditors should avoid on-site NCR acceptance on the last day of the audit as there may not be sufficient time for the Supplier to conduct an adequate RCCA analysis in order to support acceptance on site.. ƒ Auditors shall carefully review the heat treating processes that are recommended for accreditation together

with the Supplier early in the audit. At that time verify all appropriate specifications are in the facility. At this point the scope of accreditation shall be discussed with the Supplier, and any required additions or

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Verification” process. Refer to the eAuditNet Auditors” Guide under “Public Documents”

C.5 Verification of Corrective Action (VCA) Audits

ƒ VCA audits are required by the Task Group whenever there are significant findings is areas such as pyrometry or Customer flow down which would indicate corrective actions need on-site confirmation. The scope of the audit shall be limited to the requirements established by the Staff Engineer and Heat Treating Task Group, and any NCRs shall be answered in the same manner as a standard audit. A letter will be sent to the Auditor from PRI which details the required scope of the VCA audit. This letter is to be attached to the checklist on page 2 of the VCA audit in eAuditNet. The original audit will not be closed until the VCA audit is closed.

ƒ A complete and thorough Cover Letter is now the official method allowed by the Task Group when

documenting the review of previous NCR’s written when performing a VCA audit. Each NCR shall be listed and what actions were taken to close that NCR. If the letter is not complete and thorough, it will be rejected and the Auditor will have to rewrite the Cover Letter to the satisfaction of the Task Group. This letter is to be attached to page 2 of the audit in eAuditNet.

C.6 Snapshot Audits Definition

ƒ A Snapshot audit is an audit performed upon Task Group request, by a PRI/Nadcap Auditor, at PRI/Nadcap expense, without extended notice given to the Supplier. The purpose of Snapshot audits is to verify the implementation of corrective action responses. Snapshot audits are very focused, with the scope of the audit defined by the requesting Task Group and not to last more than two (2) days. Poor performance on a Snapshot audit could result in revocation of accreditation.

C.7 Satellite Audits

• Unless specifically directed by PRI, DO NOT visit more than one Supplier location as part of the audit, even if the Supplier tells you that their facility is comprised of more than one site. Call PRI for confirmation regarding the extent of the audit.

• When more than one location of a Supplier is authorized for inclusion under an accreditation certificate, separate checklists should be completed, for each location, per method, independently. Audits of each independent location have requirements that differ from Task Group to Task Group. eAuditNet will contain the individual checklists to be used with separate audit numbers. • The Main and Satellite facility audits shall be scheduled consecutively with the same Auditor(s).

Staff Engineer approval of deviations shall be noted in eAuditNet. ƒ For Satellite(s) the following criteria apply:

ƒ Must be within 25 miles/40 kilometers radius distance of the Main facility; ƒ Must have the same Quality Manual and Procedures as the Main facility;

ƒ Must have the same Quality Manager (day-to day operational control) as the Main facility (for NDT can substitute the same Level III / for MTL can substitute the same Lab Manager/Supervisor);

ƒ Must have onsite an individual who is part of the Quality Function and reports directly to the Quality Manager;

ƒ Are owned by the same company.

ƒ The Auditor shall verify during the audit that the Satellite meets the above criteria and shall immediately report any deviations to Scheduling. The Auditor shall document that the above criteria was met or not met in the audit report cover letter.

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C.8 Spec Cancellations & Supercession

• Suppliers and Auditor must not assume that the latest revision of a specification is the one to be used. Many Primes, for certification and qualification reasons, are required to continue to use prior revisions or even to continue to follow superseded or cancelled documents. Most Primes provide a flowdown to at least their first tier. When in doubt, consult the Prime. All active Task Group member Primes have committed to supplying this information if help is needed.

For ASTM, AMS and other national standards specification revisions, the Heat Treating Task Group has agreed that the Supplier shall, within 90 days, have the latest revision of the specification on site in the absence of other direction from Prime or customer specifications.

C.9 AC7102/S

• General and specific requirements for application of AC7102/S:

• DO NOT respond to any question in AC7102/S where the cited Prime specification has NOT been flowed down. Enter “N/A” instead.

• DO respond to those questions where the cited Prime specification has been flowed down. • The GE-Aviation (U10) questions are rated as follows for the purpose of categorizing an NCR:

Minor: 11.2.1 (Vacuum leak rate test’s starting pressure) 11.2.1 (Dew point measurement frequency) Major: 9.1.2 (Cooling Rate)

10.2 (Load Sensor Accuracy)

11.1.4 (Type D + 2 recording load sensors) 11.2.1 (Vacuum system calibration interval)

11.2.1 (Dew point instrument calibration frequency) 11.2.4 (Vacuum level above 1000F)

• Rolls-Royce PLC (U3) questions are rated as Minor for the purpose of categorizing an NCR. No questions should be answered “N/A” or partially answered questions.

• GE Aviation specifications that flows down P10TF1: o C50TF8 o C50TF22 o C50TF26 o C50TF113 o C50TF119 o P11TF18

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D. QUALITY SYSTEMS

• The Supplier should maintain a Process Control Matrix that lists all of the specifications that they process hardware to, the applicable process control requirements, and the Suppliers schedule for meeting them. • The Supplier must have a documented and effective internal audit system. Evidence of these audits

including schedule, audit criteria, and results including associated corrective actions must be available for review by the Auditor.

• The heat treating job planning must include the specific time and temperature requirements for the specific job. This information can be directly on the shop paper or on other instructional media traceable to the job planning. It is not acceptable to reference by specification and have the operator look up the time and temperature requirements in the specification.

• For fixed process planning, the Supplier must be able to document to the Auditor that they are processing to the latest Customer approved revision of the fixed process planning.

• The Boeing Company requires for BAC heat treating specification that each furnace chart is stamped to indicate acceptance for temperature and time at temperature. If this inspection is delegated to shop production personnel by QA, then the operators must receive documented training and QA must perform oversight audits on sampling frequency of the jobs accepted by the operator. A record must be kept to document this oversight.

• Sampling Plans - Personnel utilizing sampling inspections must be trained and tested to document that they know how to properly perform sampling inspection.

D.1 Training

• The Supplier must have a documented personnel training program. The Supplier can use ARP1962 for a guide, or develop their own training program. The program must include documented training to an established outline and initial and periodic evaluation of the competency. The AMEC committee is concerned about the quality of the training programs at heat treaters and feels that we have not been putting enough emphasis in this area. This is an area that we need to highlight.

• Where written testing is not permitted (for example, in certain union shops), "Observational" testing is acceptable. In this kind of test management observes an operator during the performance of their job duties. Management fills in the questions and the result is graded. The results of the observation should be reviewed with the operator. Records of the observations and review must be retained.

D.2 Electronic Program Control and Data Acquisition

• These requirements pertain to computerized furnace programming, paperless recording equipment, and any other electronic media used by a heat treater that historically was performed in a hard copy format. The Heat Treating Task Group does not want to discourage the use of this type of equipment (in fact would rather encourage it), only to ensure the proper steps are taken to control software and data to be as reliable and auditable as the hard copies they replace. For more specific information, refer to AMS2750 Rev D and the Pyrometry Reference Guide.

D.3 Contract Review

Where the Customers instructions are ambiguous with regards to thermal processing and mechanical testing requirements, e.g. 17-4PH, Heat Treat to Condition H1025 per AMS5643, it could imply that Customer requires testing with heat treatment; heat treaters shall contact Customer for further clarification of all requirements, which may include verification of delivery condition.

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E. GENERAL HEAT TREATMENT ITEMS AND STEELS (AC7102)

• Refrigeration of Steels - If the specification requires a refrigeration time at temperature process, it must be recorded to document compliance. This includes dry ice/alcohol baths. Refer to AMS2750 Rev D and the Pyrometry Reference Guide for further information.

• If the Supplier is performing in-house testing covered by one of the MTL checklists, e.g. Hardness Testing, Tensile testing, etc., they will need to consult the MTL Supplier/Auditor Handbooks for guidance to those checklists.

E.1 Test and Inspection

• Supplemental Material Testing Laboratory Checklists - As part of Nadcap Heat Treating audit, Suppliers may be audited to checklists that are to standard operations in a heat treating facility, but out of the Heat Treating Task Group’s control. For instance, checklists handled by Materials Testing Laboratories (MTL) Task Group for such testing like Mechanical Testing (AC7101/3) and Metallography and Microhardness (AC7101/4) are common. Interpretation and guidance on these checklists are available from the MTL Task Group.

E1.1 Room Temperature Tensile Testing

• Round Robin testing is required when the Supplier performs RTT per AC7101/3 Table 1. (Guidelines to follow when available.)

• When the Supplier only performs RTT, calibration and monitoring of temperature and humidity is NOT required, do not write an NCR, the question is N/A.

• The following are the only areas in AC7101/3 & 4 the Heat Treating Auditors are allowed to verify for approval.

• The only allowed category of testing in AC7101/3 is RTT.

• The only allowed categories of testing in AC7101/4 for approval are the following: L, L5, L6, L7, L8 and L9.

E1.1.1 Sub – Contract Machining of RTT Test Pieces

These are the minimum requirements for the control of machining of RT Tensile test pieces against the clause in AC7101/3 Para 9.4. The machining source does not need to be listed on AC7101/1 Figure 3. Machining source

The source must be listed on the Supplier’s approved vendor listing. They must be able to demonstrate a quality review of the source.

Control of RT Tensile Test Piece Manufacture:

1) Are procedures written which establish specific values for each process variable for each test piece and material combination, i.e. machining speeds, feed, grinding wheel, etc?

2) Does the preparation of the test piece eliminate any adverse effects on the properties resulting from the test?

Example:

a) Test piece distortion b) Physical damage c) Residual stresses

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3) Are the test pieces inspected for the following? a) Visual inspection for surface damage

b) Finished surface exhibiting an uniform texture

4) Is dimensional inspection controlled by one of the following methods? a) Statistical Process Control (SPC)

b) Inspection of characteristics prior to shipment c) 100% inspection of all characteristics

d) Sample inspection of characteristics.

5) Are the packaging and shipping requirements defined?

Are each of the specimens packaged and labeled in a manner to protect its integrity and unique identity? E1.2 Round Robin Programs for Metallography and Microhardness

Internal round robins are required for accredited Heat Treating Suppliers for their microhardness testing equipment and other measurable metallographic evaluations. External round robins are not required. The internal round robin test should include:

a. Operators who use the same tester: using the same specimen, with none of the operators aware of the hardness block value, at least five readings are taken for each operator and compared

statistically.

b. If there are two microhardness testing machines using the same scale (ex. Knoop) one individual should test both machines with the same block to determine if there is a statistical difference between the two machines?

c. For both machine and operator, the results shall be analyzed quantitatively. Any valid statistical

method that compares the data with 95% confidence is acceptable. For example, individual test

averages should fall between two standard deviations of the total test data.

ƒ Round robin testing shall be performed on each microhardness tester used to verify or certify material regardless of the type of tester. This includes digital microhardness testers.

ƒ

The Krautkramer Microdur microhardness tester requires the use of a separate material standard test block that corresponds to each alloy system to be tested.

For the purposes of the Heat Treating Task Group (this is not a true Gage R&R): A statistical comparison of microhardness test machine operator results on a given microhardness test machine (including digital machines) and hardness test block. Operators should be “blind” to the test block value being used. Readings should not be rounded. An individual’s mean shall be within +/-2 sigma of the group mean. If more than one machine is to be used, each machine must be checked. Have one “standard”

microhardness test machine operator check each machine and compare other microhardness test machine operators against the “standard operator”. Round Robins are also required for IGA/IGO and diffusion coatings and RTT, grain size, alpha case. (Review MTL data)

The following may be considered to assist in Round Robin calculations:

Round Robin testing is a comparison between two or more operators or between same scale

microhardness testers to assure there is no significant statistical difference in the testing methods used between operators or between the functioning of hardness testers. For operators, the same

microhardness tester and same certified test block (test value of the test block is obscured to prevent bias - production material is not recommended, as this material is often not consistent in hardness and the test will be confounded) is used and a number of test readings (five or more) is taken by each operator. The test results of each operator are compared statistically to each other. If there are more than two operators, one is always used as the standard of comparison. The same method is applied to microhardness test machines when there is more than one microhardness tester. Recommended

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statistical methods are” t” test, 2 sigma average comparison (individual average does not exceed two

sigma of total average)

When comparisons are made where only one measurement is made (depth of IGO, depth of alpha case, grain size, etc), the same sample is measured by different individuals using the same equipment. A

recommended statistical comparison is a “Z” test, Z=(x-X)/s, where Z (the number of standard deviations the value of “x” lies above or below “X”), “s” is the measured standard deviation of the average of the readings to obtain “X” , “x” is the participant’s result, “X” is the determined value from a number of acceptable readings. For IZI less than or equal to 2, the test is satisfactory; for 2 less than IZI which is less than 3, the test is questionable; for IZI greater than or equal to 3 the test is unsatisfactory (reference ISO/IEC Guide 43-1:1997, ASTM E 1301

E1.3 Surface Contamination Testing

Some Primes require or allow the use of ARP1820 for the testing of surface contamination/decarburization. The following specifications reference surface contamination requirements in Section 3.5 of each

specification and ARP1820 is referenced in all AMS 2759/#’s. ƒ AMS 2759/1(ARP 1820 is referenced, but not required) ƒ AMS 2759/2(ARP 1820 is required)

ƒ AMS 2759/4(ARP 1820 is referenced, but not required)

ƒ AMS 2759/5(Requires ARP 1820 or equivalent that provide 3X magnification)

NOTE: AMS-H-6875 requires etching the IGA sample in boiling acid. AMS 2759 specifies that samples should be evaluated unetched.

E1.4 IGA/IGO Evaluation

IGO is an oxidation of the grain boundaries, leaving the grain intact. IGA is a corrosion attack in the grain boundaries that usually results in the grain(s) being removed or damaged. All alloys exposed to thermal treatments are susceptible to IGA/IGO, with the exception of single crystal castings. Always refer to controlling specifications for requirements. Refer to ASTM E 3 for preparation of sample or indicated specification. Individual Prime requirements may differ.

• Do procedures reference compliance to ASTM E 3 or indicated specification?

• Do records show compliance to ASTM E 3 for specimen preparation or indicated specification? E1.5 Hardness Testing (AC7102/5 Rev. NA)

Question 13.4.1 was intended only as a reminder that the requirements of ASTM E18-08b Paragraph 6.4 apply, where it states "When testing on convex cylindrical surfaces, the result may not accurately

indicate the true Rockwell hardness; therefore, the corrections given in Annex A6 shall be applied." Whenever a Supplier certifies that they have performed hardness testing per ASTM E18, they are certifying that corrections were applied to hardness values taken from convex cylindrical surfaces.

The question 13.4.1 from AC7102/5 Rev. NA will be removed from the checklist at the next revision.

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or contract.

E.2 Furnace Document Control

Do records on the furnace chart or log indicate that the procedure is followed?

When looking for furnace logs, follow the specification governing the job of concern. Some require actual logs with specific information on them be kept, others require only written traceable records.

E.3 Control of Heating Environment

Do procedures specify how atmosphere from each generator/blender is to be controlled? Refers to generated atmospheres (endothermic for example), not for blended cryogenic atmospheres E3.1 Hi-Limit Instruments

While out on the shop floor be sure to check the Hi-Limit Instruments and to verify they are properly being set. There are several different specifications that require them to be set at a specific range above the set temperature. If the specifications do not call out such a requirement, the Supplier needs to define in a procedure what the hi-limit instruments need to be set at.

E.4 Quench Systems

There are three types of delays to be considered in heat treating, dependent on the Customer specification:

a. Quench delay: fromthe time which the furnace door starts toopen (i.e the furnace seal is broken) until the parts are completely under the water, polymer, salt or oil.

b. As Quenched Retention Delay: The times from removal from the quench bath until the parts are put in refrigeration / sub-zero treatment (usually 45 minutes maximum for steels and 1 hr. for aluminum, but frequently less depending on alloy and specification).

c. Age/Temper Delay: the time the parts must remain at room temperature after removal from the refrigerator prior to placement (usually some minimum time) into the aging/tempering furnace.

When these requirements are imposed by specification, records of time in/time out need to be kept by the heat treaters.

Are the quench mechanisms operational and capable of meeting maximum quench delay provisions of specifications?

Quench delay measurement should be verified to assure specification compliance. Measurement begins with movement of the door. Tabulated maximum delays may be exceeded if allowed by specification i.e.

AMS2770G states that the specified maximum quench delay may be exceed if tests made within the last year demonstrate that the part temperatures do not fall below 775 °F (900 °F for 2219) before immersion. In addition, there should be documentation of how the temperature of the parts is validated when using this provision. The measurement of quench delays should be done with a stopwatch. Too many new furnaces measure from the initiation of ram movement or from the time the door is fully open, and not door movement. Lengthy delays can cause defective parts.

Do procedures specify how quenchant temperature is to be controlled and documented?

There should be a document describing how the temperature in the quench bath is measured at the start and end of the quench.

Do records on or traceable to, the traveler demonstrate that quenchants have been at the specified temperatures before and after the parts were quenched?

Supplier should be checking the quenchant temperature rise with a full load. Load sizes should be controlled to ensure that quench media does not exceed the maximum quenchant temperature allowed by specification or the maximum allowable increase in quenchant temperature allowed by the specification.

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ƒ Control of glycol quenching solutions. The current industry/Customer specs have rigid controls with respect to glycol concentrations, salt content in the quenchants, and require approved products. Checking of

quenchants approval is essential. The adequacy of the quench in aluminum heat treating operations is dependent upon the use of specific products, and the continued control of those quenchants.

Do records indicate that quenchant effectiveness is consistent and meets specification requirements?

Quench effectivitytesting may include (either separately or in combination) comparative cooling curve analysis, analysis of mechanical property test results, chemical, physical & thermal analysis of the quench media, and hardness of cross-section analysis against harden ability curves. See the governing heat teat specifications for details.

E.5 Vacuum Considerations

Do procedures control the following: a. Leak-up Rate

Leak-up rate test should be run at normal operating pressures. Allow vacuum system to equilibrate for 15 minutes minimum then check leak-up rate. The typical leak up rate is expressed in microns/hour and the arithmetic should be performed accordingly.

Example if the test is run for 15 minutes, the pressure difference during the time period multiplied by 4 equals total leak up rate per hour.

b. Quench Gas Purity and Dew Point (Does gas certification meet specification requirements)?

Quench Gas Purity: This relates to the purity and dew point requirements of the quench gas. For example, GE Specification, P101TF1, requires inert gas purity of 99.995% and dew point of -60 degrees For colder. Boeing BAC specification requirement is Compressed Gas Association (CGA) specification G–11.1, Grade E (dew point –76 F or colder, oxygen 5 ppm or less).

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Table II Moisture Conversion Data

Dew Point (°F) Dew Point (°C) Moisture Content [ppm (v/v)] Moisture Content (mg/L) -100 -73.3 1.5 0.0011 -95 -70.5 2.3 0.0017 -90 -67.8 3.5 0.0026 -85 -65.0 5.3 0.0040 -80 -62.2 7.8 0.0058 -75 -59.4 11.4 0.0085 -70 -56.7 16.2 0.012 -65 -53.9 23.0 0.017 -60 -51.1 32.0 0.024 -55 -48.3 45.0 0.034 c. Gas Quench System Integrity/Dew point

When dew point testing of inlet gases to a line of furnaces; take the gas sample just past the farthest furnace in the line. Look for periodic calibration of dew point tester.

E.6 Racking

• Racking spacing should be conveyed by planning callout, set up cards, or in the general procedure depending applicable specifications/Customer requirements.

• Heat treatment of fasteners frequently requires specific qualification of containers to insure that that the soak time is adequate for a given thickness of charge and that the charge is not too thick for adequate quenching. Various specifications have specific requirements in this area.

E.7 Re-Heat Treatment

All re-heat treatments must be documented on the Suppliers manufacturing and nonconformance system, even if re-heat treatment is allowed by specification. If re-heat treatment is not specifically allowed by specification, Customer approval in writing is required.

F. PYROMETRY AUDIT INTERPETATION

PLEASE REFER TO THE “PYROMETRY REFERENCE GUIDE” FOR GUIDENCE ON THE REQUIREMENTS OF AMS2750.

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G. JOB AUDITS

G.1 Job Selection

ƒ Job audits shall be selected to provide a representative appraisal of the type of work to be accredited. Job audits are a good test for the effectiveness of the Supplier’s contract review procedures, process planning and manufacturing controls. Be careful of customer specific flowdown requirements that may preclude the use of “generic” or “industry-specification” based process plans or cycles. Survey the facility early in the audit to find enough in-process jobs for a minimum of 4 in-process job audits. Make Supplier aware that other completed job audits will be required if all materials/processes cannot be covered in-process. ƒ If a Supplier wants approval for any of the following materials/processes listed in Table III, then an audit

must be conducted on that materials/process. It is essential that the Supplier be contacted prior to the audit to ensure he has material in process to cover the scope of approval If the Supplier does not have current orders in house, he may run “dummy” jobs to the requirements which he wishes to include in the scope of his audit. This needs to be agreed to prior to the start of the audit. The job audits can be either long or short. If an in-process job is not available, then the auditor can select a Supplier's completed job. As many job audits as necessary to completely document a Supplier's capability should be performed. This applies to both initial and reaccreditation audits..

Table III Job Audit Selection

Titanium solution treatment Furnace Brazing

Aluminum solution treatment Carburizing and heat treatment

Austenitize and quench Nitriding

Superalloy solution with controlled cooling requirements or aging with controlled cooling requirement

Induction Brazing Dip Brazing

Induction hardening Ion Nitriding

ƒ Tempering and/or Stress Relieving alone can’t be used as a job audit unless that is the only process the Supplier performs. Solution treating and aging of same part number should be considered as one long job audit.

ƒ Preference should be given in selecting jobs to Subscribing Prime members of the Heat Treating Task Group. Should avoid “breakout” job, i.e. direct government buy of Prime part numbers.

ƒ Preference should also be given to non-proprietary jobs and/or non-ITAR/EARwhen choosing to do an audit. If there is no choice and a proprietary job has to be chosen, a record of specification requirements, set values, and actual values should not be placed in the audit report unless agreed to by the Supplier. Instead, the Auditor shall verify the specification requirements versus the shop paper requirements versus the actuals and make a statement that the condition found was acceptable. If an NCR exists, it is

acceptable to record the variance from requirements. Please refer to NIP 7-07 for additional information on ITAR/EAR.

ƒ Long job audits shall be performed on completed aerospace jobs. Long job audits should be performed on jobs completed within the last four months. Only if there is no other work available should a completed job be more than 6 months old. If it is older than 6 months:

o Make a specific note

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ƒ At least four short job audits should be performed on in-process jobs if eight in-processes are not available. If it is impossible to witness a minimum of four in process jobs, a Staff Engineer must be contacted. The Staff Engineer will give direction to the Auditor in proceeding with the audit and proper documentation in the cover letter. The remaining jobs must be selected from the completed jobs since last certification was issued.

ƒ A minimum of at least one in-process job needs to be witnessed to observed racking details, placement of load t/c (if used), placement in furnace, quenching and unloading. The balance of the in-process jobs may be in soak, in cool down cycle or just completed.

G.2 Auditing Notes for Job Audits

ƒ Identify alloys/materials specifically-not just by specification number.

ƒ Ensure that material is heat treated in furnaces that meet the uniformity requirements of that material (i.e. material requiring ±5 F ovens are not aged in ovens that only meet ±10 F limits).

ƒ Solution heat treating and aging of the same aluminum part number may be treated as two separate short job audits, especially since two different furnaces will likely be used. There are some that are used for both solution treat and age but this is not common.

ƒ Each question in each job audit must be answered. For example, Pre Heat Treat Requirements; Pre Heat Treat Requirements on shop paper, Pre Heat Treatment actually performed, must be answered. If there are no requirements, write "NONE" or "NONE SPECIFIED".

ƒ If the customer requirements are not specified, the heat treaters must provide objective evidence of the origin of the requirements imposed.

ƒ When recording the “Actual Temperature Data”, it is best to record the stabilized temperature and not the temperature as the thermocouple crosses the lower uniformity requirement.

ƒ Specification, B/P and/or P.O. calls out a minimum time only, it is permissible but NOT required that the Supplier specify a maximum. The Supplier may simply flow down the minimum time requirement to the shop paperwork. If Specification, B/P and/or P.O. calls out a single time only and does NOT state Minimum/Maximum, the Supplier Shall have a default in their procedure. Either a (+/-) tolerance or a statement that time at temperature shall be considered as Minimum or Maximum. This also applies to a “Fixed Process”. The only exception is for a fully automated process outside the control of the operator. A single time may be specified in such cases.

ƒ During all job audits where quench delay requirement exists, the Auditor needs to verify that the requirement was met.

ƒ The preferred practice is to list the date & time of day on the recorder chart. Additionally, there needs to be traceability from the chart to the heat treat log, for example, by using a job number and date or unique job number.

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H. BRAZING

H.1 Considerations

ƒ Because there are a number of requirements unique to brazing, the Heat Treating Task Group has developed a separate slash sheet (AC7102/1). Suppliers wishing to be approved for furnace brazing, dip brazing or vacuum brazing shall be audited to this slash sheet.

ƒ Suppliers wishing to be approved for torch brazing or induction brazing shall be audited using AC7110/1 checklist.

ƒ Adjusting of temperature during the hi-temperature portion of braze cycles, based on load t/c data is allowed in order to avoid adverse affects of exposure at elevated temperatures.

ƒ NOTE: This is not considered ‘Offsetting” as it is used during temperature uniformity surveys.

ƒ Not all Primes require a separate enclosed preparation/assembly area, but area used for this must be reasonably free of shop dirt and potential sources of contamination.

ƒ Fit is critical to a strong braze joint make a special point of reviewing the Suppliers data and assembly procedures to assure B/P or specification requirements for gap are met.