and A.4.2, Table A.16 QUESTION:

We manufacture a fluid-handling product machined from UNS N06600 in the cold- worked condition with a hardness less than 35 HRC. We have certified that this product meets MR0175 based on Paragraph 4.1.4.1 of MR0175-2002.

a) It appears this material is not included in MR0275-2003. Is it acceptable to certify that this material meets MR0175-2003 based on the listing in previous versions? b) If not, is it acceptable to continue to certify meeting MR0175-2002?

(MP INQUIRY #2003-10 Q2)

ANSWER:

The MP cannot provide interpretations involving the certification of equipment. We can only interpret the current edition of MR0175.

The MP will investigate the history of this alloy in NACE MR0175 and may make an amendment proposal to re-include it.

QUESTION:

Old (2002) Paragraph 4.1.5.1 UNS N06625 HRC >35

New (2003) Paragraph 4.11 and A13: N06625 solution-annealed only: Technical justification?

(MP INQUIRY #2003-27 Q2)

ANSWER:

The consensus during the balloting process for the 2003 edition was that no

hardness limit was required for solution-annealed material. Alloy manufacturers did not object to the change.

A.4.1 and A.4.2, Table A.16 QUESTION:

We believe that Alloy 400, UNS N04400, should be included in both the latest version of MR0175 and the imminent ISO 15156 standard. As outlined in the foreword of MR0175-2003, “Many of the guidelines and specific requirements in this

standard are based on field experience with the materials listed . . . “

We propose that Alloy 400, UNS N04400, be added to Section 8, Special

Components, Paragraph 8.4.2, Diaphragms, Pressure-Measuring Devices, and Pressure Seals.

(MP INQUIRY #2003-07)

REVISED ANSWER 2005-09-01:

The revised version of Table A.13 is included in Reference 3.

In what paragraph are the requirements for wrought bar in nickel-copper alloy (i.e., UNS N04400 and N04405)? In the 2002 version, these materials were covered in Paragraph 4.1.1.

(MP INQUIRY #2003-09 Q1)

ANSWER:

These alloys, UNS N04400 and N04405, are no longer in the standard except in Paragraphs 10.6.2.2 and 10.7.3.

QUESTION:

We manufacture a fluid-handling product machined from UNS N04400 and N04405 in the cold-worked condition with a hardness less than 35 HRC. We have certified that this product meets MR0175 based on Paragraph 4.1.1.1 of MR0175-2002.

a) May we continue to certify that this product meets MR0175-2003, since this material is mentioned in Paragraph 10.6.2.2?

b) Is it acceptable to continue to certify meeting MR0175-2002?

(MP INQUIRY #2003-10 Q1)

ANSWER:

The MP cannot provide interpretations involving the certification of equipment. We can only interpret the current edition of MR0175. Paragraph 10.6.2.2 states that UNS N04400 and N04405 may be used for gas lift equipment.

QUESTION:

What are the reasons for the exclusion of nickel-copper alloys, e.g., UNS N04400, from the materials listed in Section 4?

(MP INQUIRY #2003-26 Q1)

ANSWER:

The wrought nickel-copper alloys were removed from the general section of NACE Standard MR0175 because of concerns from field failures of UNS N05500. It was expected that as a result of ballots over the 6-plus years of drafts that the 2003 edition of MR0175 would include the reinsertion of UNS alloys N04400 and UNS N04405 into the appropriate equipment sections. This has not been the case. There has not been a single ballot for including these alloys. However, the ISO Maintenance Panel has agreed to put forward for ballot to the ISO Oversight Committee and ISO WG 7 a proposal to include these two alloys into the Instrumentation and Control Devices Paragraph 8.4. If the ballot passes, the alloys will be included in a 2004 addendum to ISO 15156/NACE MR0175-2004 in the table currently numbered A.16.

QUESTION:

NACE Standard MR0175-96, Section 4, includes Paragraph 4.1.1 titled Nickel- Copper Alloys specifically listing UNS N04400 (K-Monel), UNS N04405, and N05500. These CRA metals have been omitted from MR0175-2003 except for brief mention under Section 10 for specific equipment not related to our business. We are a manufacturer of process gauges, some of which are for use in sour gas environments. These metals (especially N04400) have always been used in our (and other manufacturers') gauges for pressure-containing parts having direct exposure to sour gas. Have these materials been omitted for a reason or are they still acceptable?

(MP INQUIRY #2003-29)

MR0175 was revised based on several years of balloting and input from NACE TG 081 members. Several alloys were eliminated from the general section of the document because members were concerned that these alloys were being used without appropriate restrictions to the environment. There were no ballots, or comments on ballots during this process, to insert Monel alloys back into the document in the section on gauges. The MR0175 document will within this year become ISO 15516/MR0175. At this time, ISO/NACE will begin to accept ballots for revisions. Attached is the standard format for balloting. Prior to or in lieu of balloting, Section 16 may be used... Also, please note that in Paragraph 1.10.2, “The user may replace materials in kind for existing wells or for new wells within a given field if the design basis for the equipment has not changed.” This Paragraph allows customers to purchase materials that have provided satisfactory performance in the past, even if the materials are not listed in the current 2003 edition.

QUESTION:

We manufacture instrumentation and in particular, BOURDON TUBE-type pressure gauges. Due to the manufacturing process, 316 SS tube exceeds the hardness limit in NACE MR0175. The alternative has always been to supply “MONEL” UNS N04400 to comply with NACE MR0175. Paragraph 8.4 would previously have referenced N04400 in Section 4, thus meeting the requirements. We note N04400 is referenced in Section 10 only, specific to downhole equipment. We are holders of your standard NACE MR0175-2003. We have a particular query regarding UNS N04400. The 2003 edition of the standard does not contain in Section 4 (CRAs) a section for nickel-copper alloys (NACE MR0175—ALL PREVIOUS ISSUES), and as UNS N04400 does not fall within the stated parameters within Section 4, can you please clarify: Is UNS N04400 no longer within the scope of MR0175-2003 section 4, or will an amendment be issued to re-include it in Section 4?

(MP INQUIRY #2003-31)

REVISED ANSWER 2005-09-01:

The wrought nickel-copper alloys were removed from the general section of NACE Standard MR0175 because of concerns from field failures of UNS N05500. There were no ballots for the drafts of MR0175-2003 to reinsert UNS N04400 and UNS N04405 into the appropriate equipment sections. The ISO Maintenance Panel has agreed to put forward for ballot to the ISO Oversight Committee and ISO WG 7 a proposal to include these two alloys in the Instrumentation and Control Devices Paragraph 8.4. If the ballot passes, the alloys will be included in a 2004 addendum to NACE MR0175/ISO 15156.

The revised version of Table A.13 that addresses any equipment or component is included in Reference 3.

A.4.2

QUESTION:

According to NACE Standard MR0175-2003, 625 material, as a solid-solution nickel- based alloy, is acceptable only in the solution-annealed condition. This constitutes a major change with respect to previous editions, in which 625 material was accepted up to 35 HRC regardless of the delivery condition. The annealed condition is

considered the most suitable condition by most of our customers and we are not aware of problems or failures with material 625 used in this condition for NACE applications. Unless a real problem exists in using annealed 625, we would like to understand whether:

• The definition of solution annealing given in NACE Standard MR0175-2003 has to be interpreted to exclude 625 material in the annealed condition; or

• For 625 material, annealing performed in a given temperature range (to be suitably defined, even more narrow than the range from 1,600 to 1,900°F) can be considered a solution-annealing heat treatment as defined in Section 2.

(MP INQUIRY #2003-11)

ANSWER:

Tables A.12, A.13, and A.14 in ISO 15156 provide answers to your requests for interpretations.

NACE will be adopting ISO 15156 in 2003 as a technically equivalent document. The nickel-based alloys may be used in the annealed or solution-annealed condition within the requirements of these ISO tables.

Please also refer to the definition of “solution-annealed” in Section 2 of NACE Standard MR0175. This definition does not prescribe the temperature for the solution-annealing heat treatment.

A.4.2, Table A.12 QUESTION:

Question on Alloy 31 (UNS N08031)

The typical chemical composition of this alloy is: Fe bal, Ni 31, Cr 27, Mo 6.5, Cu 1.2, N 0.20. Based on the individual heat chemistry, the alloy could be either a nickel-based alloy (nickel being the highest element) or high-performance stainless steel in which iron is the highest element.

NACE MR0175-2002:

*Alloy 31 appears in Section 4: Nonferrous Metals.

*4.1.3 Nickel-Iron-Molybdenum Alloys Paragraph 4.1.3.14 (provides allowed use and the table of balloted data).

NACE MR0175-2003: The nonferrous section is no longer present in this version. *Section 4 is now entitled “Corrosion-Resistant Alloys (CRAs)--All Other Alloys Not Defined As Carbon and Low-Alloy Steels and Cast Irons in Section 3”

*Section 4.11 Solid-Solution Nickel-Based Alloys (Category) appears to be the section in which Alloy 31 fits the category of 4.11.1: 19.0% Cr min., 29.5% Ni + Co min., and 2.5% Mo min. No specific mention of alloy 31 is made in this section. *The balloted table of data for alloy 31 appears in Appendix C: Ballot Submittal Data, Table C7.

It appears that name of this alloy UNS N08031 (alloy 31) began to disappear in this version.

I fully understand that this document NACE MR0175-2003 is no longer valid and now has been replaced by NACE MR0175/ISO 15156 First Edition, Part 3.

NACE MR0175/ISO 15156 First Edition, 2003-12-15, Part 3 (Comments and Questions)

It appears that alloy 31 (UNS N08031) should appear in Section A.4 Solid-solution nickel-based alloys.

It would further appear that alloy 31 (UNS N08031) fits the materials type 4c

described in Table A.12 as: 19.5% Cr min., 29.5% Ni + Co min., and 2.5% Mo min. Is this the material type/grouping that alloy 31 (UNS N08031) should be grouped with?

Table D.4 lists various alloys included in the Section A.4 Solid-solution nickel-based alloys. Alloy 28 (Alloy 28 in reality is not a nickel-based alloy) and 32 are listed in this table. No mention is made of alloy 31 in this table or within the document. Could 32 be a typo error and should be 31??

It appears that alloy 31 (UNS N08031) has completely disappeared from this version. I would appreciate clarification on this point. Alloy 31 (UNS N08031) should be listed in this NACE MR0175/ISO 15156-3 First Edition, 2003-12-15, Part 3 document. If this is an error, how do we get it corrected and if this is not an error how do we get alloy 31 in this document?

(MP INQUIRY #2004-15)

ANSWER:

Alloy 31 as you describe it fits in Type 4c as defined in NACE MR0175/ISO 15156-3, Table A.12.

Alloys that comply with the requirements of Table A.12 for solid-solution nickel-based alloys are not individually listed in NACE MR0175/ISO 15156-3, Annex A. The document makes use of alloy types in order to avoid the listing of all possible examples of such alloys.

Similarly, NACE MR0175/ISO 15156-3, Table D.3, as noted in its title, does not attempt to provide an exhaustive list of alloys that can meet the requirements of these types of alloys.

Please note it is not a requirement of NACE MR0175/ISO 15156 that an alloy be individually listed to meet the requirements of the document.

If a solid-solution nickel-based alloy, as defined in NACE MR0175/ISO 15156-3, Table A.12, is used within the environmental and metallurgical limits defined in Table A.13 or Table A.14 it meets the requirements of the standard.

A.4.2, Table A.14

QUESTION:

Table 4 (for precipitation-hardenable, 6Mo alloys) (NACE MR0175/ISO 15156-3, Sub-clause A.9.2, Table A.33) permits elemental sulfur in the environment at 450°F, but not at 425°F, yet again at 400°F. Where does the user discover whether sulfur is or is not acceptable for applications between these temperatures? This is odd enough, but Table 6 (for 6 Mo, precipitation-hardenable 6 Mo alloys) (NACE MR0175/ISO 15156-3, Sub-clause A.4.2, Table A.14) does allow sulfur at 425°F. Are the precipitation-hardenable versions of these alloys more resistant to cracking than their solution-annealed and cold-worked analogs?

(MP INQUIRY #2003-13 Q3)

ANSWER:

In response to your questions 3 and 4a): The data used in NACE MR0175-2003 and NACE MR0175/ISO 15156-3 represent the limits of successful laboratory tests reported to NACE so far. In some cases the available data cannot be used to answer the questions you pose.

QUESTION:

(a) Table 6 (NACE MR0175/ISO 15156-3, Sub-clause A.4.2, Table A.14) permits sulfur at 300°F in any H2S partial pressure, but not at 425°F. Where, if anywhere,

between 425°F and 300°F are alloys in this category sulfur-resistant? If an oil- company client has a well with bottom-hole temperature of 350°F with produced brine that contains sulfur, will an alloy like 2550 (UNS N06975) be sufficiently resistant, or (b) must C-276 (UNS N10276) be deployed?

(MP INQUIRY #2003-13 Q4)

ANSWER

(a) In some cases the comparisons you make are not strictly valid because the data sets for the materials considered vary in the H2S limits, in the temperature limits, and

in the metallurgical limits that are imposed. It is thought that the limits given are conservative and further testing could demonstrate that the true limits are less restrictive than those shown; see also the answer to MP Inquiry #2003-13 Q6 under ISO 15156-1 Clause 5.

ANSWER:

(b) UNS N10276 would be acceptable.

QUESTION:

Could you please confirm that the kPa units of the H2S column of ISO 15156-3,

Table A.14 are incorrect and that the units should be MPa not kPa?

(MP INQUIRY #2004-07)

REVISED ANSWER 2005-09-01:

The revised version of Table A.14 is included in Reference 3.

QUESTION:

NACE MR0175/ISO 15156-3: We make bellows for use in Safety Relief Valves. We use all nickel alloy materials but we are particularly concerned with Inconel 625/Inconel 625LCF. In previous editions of the NACE standard, the material

hardness value for UNS N06625 is clearly stated as being acceptable to 35 HRC maximum, but in the above-referenced latest edition we are finding it difficult to trace this requirement and keep our records and practices updated. Would you please confirm the hardness requirements stated in the above-referenced latest edition and also reference relevant paragraphs and tables.

We buy the strip material in the solution-annealed condition, but there is a certain amount of work hardening that takes place during the bellows forming process.

(MP INQUIRY #2004-10)