Welding under the scope of NACE MR0175

[jim]

Since I need to weld plate SA-516 Gr 60 with thickness 30mm to ASME IX in conjunction with NACE MR 0175, I would like the EN 10204 3.1 certificates (not only for the raw material but also for the welding consumables) to state compliance with that NACE. Even the raw material certificate covers such a requirement, the manufacturer of welding consumables (ER70S-6, E7018-1) has told me that such a statement of compliance could not be done on the 3.1 certificate of the welding consumables. After having reviewed the NACE MR 0175, I believe that these filler metals are in compliance with the requirements of this standard and I am not able to understand the refusal of the manufacturer. Could any one advise me and moreover if possible give me some instructions for such a welding.

[Ballbearing]

Jim,
There is no requirement for a manufacturer to state NACE MR0175 on their certificates.
Their carbon steel GTAW wire for example must comply with AWS SFA 5.18 and that is all they are interested in.
Your requirement is not a code requirement, it is a specification requirement.
If you want NACE compliant welding consumables you would have to order them as such - eg. max Carbon, max Manganese, max Silicon etc and even then there is no guarantee that they will state NACE MR0175 compliant on the certificate.
Why not print out the welding consumable requirements from NACE MR0175 and attach it to the back of the consumable certificate ?
I do not have access to NACE MR0175 - does it state your 3.1 welding consumable certificate must "list" compliance with NACE MR0175 or just that they must comply with the standard ?
Cheers,
BB

[Peter Johansson]

The manufacturer of the filler metals does not give you NACE compliance certificate since such a compliance depends on the specific characteristics of the equipment like thickness of the materials, raw material designations, PWHT requirement, etc. For example, if you perform welding as per ASME IX of carbon steel plate in thickness 40mm without doing PWHT then this welding may not be in compliance with NACE requirements.

As far as this specific combination of plate and filler metals are concerned, they can cover the NACE requirements provided that:

The SA-516 Gr 60 steel met the below requirements:
1. It has been produced as hot-rolled (if it is flat rolled then it shall met the heat treatement and chemical composition requirements of NACE MR0175).
2. It shall have hardness lower than 22HRC.
3. It shall contain less than 1% mass fraction nickel (Ni).
4. It shall have carbon equivalent CE=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15 less than 0.43%.

The welding shall met the following requirements:
1. The qualification of the welding procedure shall include hardness testing that shall be as defined in table A1 of NACE MR0175 (at your case: The hardness shall be lower than 250HV10 or 5 for weld root/weld cup. The weld cup hardness could be maximum 275HV10 or 5 if the equipment user agrees, the parent metal(s) are over 9 mm thickness and the weld cap is not exposed directly to the sour environment).
2. If the hardness requirement cannot be met, then PWHT is required at 620 deg C. The maximum weld zone hardness shall be 250 HV10 or 5.
3. The filler metals shall contain less than 1% mass fraction nickel (Ni).
4. Taking into consideration the chemical composition of the raw material and its thickness, the necessity of preheat (as defined in ASME VIII, Appendix R) and PWHT (as defined in ASME VIII, UCS-56) should be verified.

[jim]

Ballbearing, the NACE MR0175 does not state that the 3.1 welding consumable certificate must "list" compliance with this standard as well as it does not give specific requirements for the welding consumables and thus there is no such a printing out that could be attached to the back of the consumable certificate. Instead it states that consumables should be selected in accordance with good practice and to achieve the required cracking resistance as well as it establishes requirements for the PQR. After yours and Peter's posts and further consideration of the NACE MR0175, I have concluded that it is the manufacturer's responsibility to select the appropriate welding consumables suitable for the intended service provided that the PQR will be qualified as required by NACE MR0175.
Thanks both of you!

[Ramin-Kondori]

The Filler metal manufacturer can not and will not give you such certificate.
You can do either of the following (or both):

1) On your PQR, you can add hardness test, chemical analysis results and CE calculations. If they meet MR0175 requirements then it will serve you as a production PQR as well as the proof that you can produce welds which meet the requirements of MR0175. You may apply pre-heat, PWHT or any other technique you are supposed to use in actual welding job.

2) You may go for all weld metal qualification that is been used for filler metal qualification and do all the required tests as per MR0175 as a supporting document for your client.

Best of luck.
Ramin Kondori
IWE AT 0070