Practicality of solution annealing heat treatment of Stainless steels?
Practicality of solution annealing heat treatment of Stainless steels?
(OP)
It is specified to do solution annealing heat treatment after welding of stainless steels & other nickel/chrome alloys. Often this is not practical if welding is done in the field (eg piping runs). This requirement is then waived?
What guidelines are available concerning the above?
When must it be done? or can be waived? What are the consequences?, benefits. What precautions or procedures may be used if it is not carried out?
Naren
e-mail: naren.sukaih@sapref.com
What guidelines are available concerning the above?
When must it be done? or can be waived? What are the consequences?, benefits. What precautions or procedures may be used if it is not carried out?
Naren
e-mail: naren.sukaih@sapref.com
Naren Sukaih
naren.sukaih@sapref.com
RE: Practicality of solution annealing heat treatment of Stainless steels?
RE: Practicality of solution annealing heat treatment of Stainless steels?
RE: Practicality of solution annealing heat treatment of Stainless steels?
Do we need solution annealing for duplex steel, UNS S31803?
The thickness of my plate is 12.7mm. Please advise. Thank you.
Regards,
Lee
hockchong.lee@akerkvaerner.com
RE: Practicality of solution annealing heat treatment of Stainless steels?
RE: Practicality of solution annealing heat treatment of Stainless steels?
As Stanweld points out it is not usually a requirement and would normally only be specified for some particular reason. Ours was removal of residual stresses.
RE: Practicality of solution annealing heat treatment of Stainless steels?
RE: Practicality of solution annealing heat treatment of Stainless steels?
Also less known is the fact that austenitic and duplex welds have significantly poorer corrosion resistance than the wrought base metal. A long anneal can reduce this problem. Patented versions of 304L and 316L have titanium additions to prevent this phenomena by gettering oxygen and sulfur before they can cause de-chromization.
RE: Practicality of solution annealing heat treatment of Stainless steels?
You should always use low carbon grades to minimize sensitization.
You should also weld with filler metals that are alloyed to help improve the corrosion resistance of the welds. In austenitic alloys this usually means higher Cr and Mo, along with higher Ni. In duplex alloys the weld fillers have a different phase balance so that the un-annealed welds end up with the correct microstructure.
In a 3XX stainless I don't like annealing temps above 2150F. But to be honest more damage is done during slow heating and cooling. If you are annealing parts that must be heated and cooled slowly you need to really know what you are doing or you can end up worse off.
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Corrosion never sleeps, but it can be slowed down.