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NACE 0175 and 0103 interpretation

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Stevemcg66

Petroleum
Nov 11, 2022
5
US
Hi All,
I'm a new user and need some feedback about hot working 316/316L SS.
Here is the scenario:
Steel mill creates a 316/316L SS billet. All the chemicals and physicals are good and they solution anneal it so it conforms to MR0175 and 0103.
Then an extruding company hot forms it into a much smaller shape for us.
Does the extruded shape still meet the NACE requirements?

I can only find where the standard addresses cold work and cold deformations and also that hot work can not he a substitute for annealing.
There is literally nothing about hot working after the anneal...so is it allowed?
 
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You said it yourself, no process anneal allowed.
After hot work it would need to be re-annealed to still meet MR0175.

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P.E. Metallurgy, consulting work welcomed
 
I'm sorry, I don't think I said no process anneal allowed.
I believe the intent of the statement is that you can't substitute a process anneal for an independent annealing process.
The material was already annealed and then hot formed which does not induce the stresses that annealing gets rod of. The important part here is hot formed which there is nothing in either standard setting hot forming is not allowed.
The question still remains...here it is in a different way.
Does a solution anneal carry through with a secondary hot forming process or does the hot form force a second anneal?
 
Annealing for corrosion resistance is done to remove residual stress and carbides. Are you introducing residual stress by hot forming (working below the annealing temperature)? Are you introducing carbides (working above the sensitizing temperature)? If yes to either then it sounds like you should re-anneal after and or skip the first anneal.
 
Curiouus... if this is so critical..., why would NACE leave it out of the standards?
 
I guess one could argue that since post work is not specifically allowed then it is disallowed.
 
Agree, but post work is specifically not allowed if cold work.
It could also be argued that hot work is allowed because it is not prohibited.
Yes?
This is my dilemma...
 
The annealing temperature is above the sensitizing range. It's not possible to do the work while staying above the annealing temp and below the sensitizing temp.

Part of the annealing process is a rapid quench through the sensitizing range. Is this going to be possible after your hot work?
 
Quench or thermally stabilized are both acceptable for annealing.
I don't have the exact hot process yet, but will post when I do.
The thermal stabilization may be key.
 
The way that we looked at this is if you can prove that your hot work is always in the anneal temperature range and meets some measured uniformity and is recorded like you would HT then quenching from above the min anneal temp would pass.
But I have never seen a hot work operation that is monitored and recorded well enough to qualify.
There are always cold spots, and no one will certify +/-25F at the end of hot work.
So we simply prohibited process annealing and required actual solution anneal as that was out reading of "hot work can not he a substitute for annealing".
I have only ever seen one operation where they extruded and then rolled the parts straight into a holding furnace.
The parts stabilized at a controlled temp and then were quenched.

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P.E. Metallurgy, consulting work welcomed
 
Which part of Table A.2 is being applied: generic, or S31603? For the latter, it will NOT comply. For the former, will the 316/316L seriously be "thermally stabilised?"

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
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