NACE MR-01-75 and Welding Stainless 316L 2

[beh188]

The way NACE MR-01-75 has been explained to me is that it is basically is a hardness limit and grain structure requirement that is needed to protect material from sulfide corrosion.

If you have NACE MR-01-75 compliant stainless 316L material, and you weld this material, does it require heat treatment after welding to be compliant with NACE MR-01-75?

My opinion would be generally no, because you cannot harden 316L stainless by the heat exposure from welding, and it is 316L material, so it should be relatively insensitive to carbide precipitation.

 

[SJones]

Not if the hardness testing of the procedure qualification demonstrates that heat treatment is not necessary.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[arunmrao]

With 316L chemistry,there is little possibility of increase in hardness,nor are the carbides likely to precipitate. You might need to demonstrate by measuring the hardness and prove conformance,so that no further heat treatment is required.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[blacksmith37]

"Someone" explained MR-01-75 wrong; It was written to prevent hydrogen stress cracking /sulfide stress cracking/
(several other names) stress cracking , of conventional steels (not austenitic). It did not address corrosion of any kind. However , who knows where ISO will take it?
TX RR Comission Forced its developement after an accident at an ARCO (former oil co.) wellhead killed several.

 

[SJones]

And the point of the above rant is what?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[blacksmith37]

The point was that MR 01-75, does not address austinitic stainless requirements, and that the ISO document may be different.
Being on T1-F1 from about 1980 to 1995, I got indoctrinated to staying on point of only dealing with HSCC/SSCC when answering inquiries.

 

[mrfailure]

In fact, post-weld heat treatment is not recommended for non-stabilized grades such as Type 316L. In particular, you run the risk of inducing sensitization because you will be in the sensitization range for additional time to allow precipitation. You also do not improve the properties you want to improve. While there are exceptions, they do not apply in this instance. Check out ASM Handbook Volume 6 p. 694-5 for a good discussion on this topic including the exceptions that would allow PWHT.

 

[SJones]

There are no technical difference between MR0175 and ISO 15156.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04