Hardness Testing

Reliance

Procedure for

Hardness Testing

EPCMD-2-QM00-JEP-ME-005

00 17.12.2011 _{Implementation} Issued for PPP / PKD PKS / EMK / KSS SNS

Rev Date Revision Prepared

By Checked By

Approved By

Reliance

Contents

1. Purpose ………..3

2. Scope ………...……....3

3. References ………..3

4. Abbreviations and Terms ………3

5. Responsibilities ………4

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1.

Purpose

The purpose of this procedure is to define the methods to be followed for hardness testing of materials / welds

.

2.

Scope

This procedure covers the approved methods and equipment to be used for hardness testing during fabrication and erection of steel piping, equipment or any other product. This is applicable for all working at Reliance projects.

3

.

References

ASTM A956 - Standard test method for Leeb Hardness testing of Steel Products.

ASTM A833 - Standard practice for indentation hardness of metallic materials by comparison hardness testers

ASTM E10 - Test method for Brinell hardness of metallic materials User Manual - Integrated Hardness Tester TH-130, Time group User Manual - Digital Hardness Tester HLN 11A, Time group User Manual - Digital Hardness tester Dyna MIC, Krautkramer User Manual - Digital Hardness tester Equotip 3, Proceq

4. Abbreviations and Terms

BHN - Brinell Hardness Number CS - Carbon Steel

DCC - Document Control Center HAZ - Heat Affected Zone HOD - Head of the Department PWHT - Post Weld Heat Treatment

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5. Responsibilities

Construction Managers / Engineer in Charge are responsible for implementing this procedure in their area.

HOD, QMD is responsible for maintaining this procedure. DCC is the custodian of this document

6.

Methodology

Contractor’s Quality Control personnel shall be responsible for the execution of hardness testing in presence of Reliance QMD persons. Any one of the following testing methods described in clauses 6.1 or 6.2 may be adopted to check hardness.

6.1 Brinell Hardness Testing by Poldi Hardness Tester

6.1.1 Prior to testing, the area shall be ground / filed flat. Grinding shall be carried out without using excessive force. No overheating or burning shall be permitted.

6.1.2 Select the Poldi standard test bar having a BHN closest to the expected BHN

of the piece.

6.1.3 Place the standard test bar between the ball and plunger.

6.1.4 With standard test bar inserted, place the Poldi tester vertically over the area to be checked, so that ball touches the ground surface.

6.1.5 Hit the plunger with a medium weight (4lb/2kg) hammer. The blow should be neither excessive nor too light and should be as vertical as possible. The blow will have two indentations – one on the standard test bar and the other on the test specimen. To minimize error, diameter of the indentation on the standard test bar should be max. 4.2 mm dia.

6.1.6 Using the microscope provided in the Poldi kit, measure the diameters of the indentations, both on the area under test and on the standard test bar. The diameters taken shall be the average of any elliptical indentations.

6.1.7 Refer the booklet provided with the Poldi kit to select the suitable table for material and its heat treatment condition. In the table, look up the column “Dia. of indentation on standard test bar” for the dia. of indentation actually obtained on the test bar. Then look up the row “Dia. of indentation on

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can be read (lower reading). To get exact hardness of the test specimen, multiply the number with multiplying factor inscribed on the standard test bar.

6.1.8 All hardness impressions at one test location should have at least 6.4mm between their nearest edges. For practical consideration, we may include 10mm.

6.1.9 Hardness impressions to be made on only two adjacent sides of standard test bar. Replace indenter ball when it is out of round.

6.1.10 All results shall be recorded on Hardness Testing Inspection Report No. EPCMD-2-QM00-FMT-ME-015.

6.2

Digital hardness testing by rebound velocity method

6.2.1 The surfaces to be tested shall be smooth and desired area shall be prepared either by grinding or hand filing. Also, paint, scales, pits or other surface coatings if any shall be completely removed.

6.2.2 The test specimen shall have 5.0 mm minimum thickness and 5 Kg weight. At the time of taking hardness the specimen shall be rigid.

6.2.3 For thicknesses lower than 10 mm and pipe dia. up to 6”, the test surface shall be either directly supported or with in 300 mm from the support. For thickness above 10 mm and or pipe dia. above 6”, the hardness can be measured irrespective of its position/ support location.

6.2.4 Standard flat support ring shall be replaced with special support rings for convex or concave in case the test specimen radius is less than 30 mm (<2” dia pipe).

6.2.5 Hardness testing shall be performed when the test piece temperature is in the range of 00_{C to 50}0_{C. For temperature out side this range, the user shall} develop a temperature correction for the specific material being used.

6.2.6 Test sample should not be in magnetized condition.

6.2.7 Connect the impact device with digital harness tester machine / processor. Set all the parameters like, Measuring direction, material to be tested, hardness parameters, etc. Average reading to be taken shall be set minimum 3 readings. (In case of TIME, TH-130 hardness tester it is single unit of combine universal impact device and processor, no separate connection is required.)

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6.2.8 Load the impact device by sliding the loading tube forward (In case of TIME, TH-130 hardness tester, loading can be done by sliding the sliding grip). Loading shall not be done at actual test location.

6.2.9 Place and hold the tester / impact device on the ground and cleaned surface to be tested. Trigger the impact by pressing the trigger button. The hardness value will be instantaneously displayed. Read/note the reading and repeat the measurements until desired average measurements are done.

6.2.10 In order to prevent the errors resulting from misalignment, the base support ring of the impact device shall be held snugly and perpendicular to the surface of the test piece.

6.2.11 When hardness is measured with digital hardness tester,

a) On all CS, for thickness less than 10 mm, whenever result exceeds 180 HB, it shall be cross checked with Poldi tester and the greater of the two results shall be considered for further action/ disposition as per governing requirements. For thickness >10mm, the above condition does not apply. b) On all AS, for thickness less than 10 mm, whenever result exceeds 210 HB, it shall be cross checked with Poldi tester and the greater of the two results shall be considered for further action/ disposition as per governing requirements. For thickness >10mm, the above condition does not apply.

6.3

6.4

Acceptance Criteria, Frequency of Tests & Reporting

Acceptance criteria and frequency of tests shall be as per applicable Codes/ Standard/ Specifications / ITP’s.

Reporting of all test results and acceptance / rejection shall be on Hardness Test Inspection Report Form no: EPCMD-2-QM00-FMT-ME-015.