316 stainless heat treatment

[djwink]

What is the recommended processing/heat treatment for 316 stainless following a forging process, i.e. time/temp/cooling method etc.? Note that only a portion of the component will be forged while the remainder of the component will remain in the as annealed condition from the supplier.

 

[Dhurjati Sen]

Dear djwink,

It depends on what is desired from the final product, else why would you go for forging at all?

Regards.

DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[EdStainless]

The typical approach would be to solution anneal the entire piece. While the unforged portion may still be fine and even the forged portion may be OK there will be a place in between where the material was heated in the sensitizing range for long enough to be an issue.
If the mechanical properties and corrosion resistance of the entire piece matter than anneal it.

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P.E. Metallurgy, Plymouth Tube

 

[djwink]

edstainless

I appreciate your response!

What temp range and method of cooling (quench, air cool, slow cool in furnace) would you recommend for the annealing process?

 

[Maui]

It depends on the section thickness of your forgings:

https://www.metalshims.com/t-316-Stainless-Steel-technical-data-sheet.aspx

These austenitic stainless steels are provided in the mill annealed condition ready for use. Heat treatment may be necessary during or after fabrication to remove the effects of cold forming or to dissolve precipitated chromium carbides resulting from thermal exposures. For the Type 316 alloy the solution anneal is accomplished by heating in the 1900 to 2150° F (1040 to 1175° C) temperature range followed by air cooling or a water quench, depending on section thickness. Cooling should be sufficiently rapid through the 1500-800° F (816-427° C) range to avoid reprecipitation of chromium carbides and provide optimum corrosion resistance. In every case, the metal should be cooled from the annealing temperature to black heat in less than three minutes.