Is ASTM A262, Practice E sufficient to ensure solution annealing of 316L stainless steel?

[Saad M.M.]

A vendor is using a continuous gas furnace for 316L stainless steel pipe solution annealing. The rolling speed is set to allow 6 minutes per mm (e.g. for 16 mm thick, the travel time is 96 minutes) including heating and soaking period in the continuous furnace. This is followed top/bottom by water spray for cooling/quenching. Distance between the furnace end and the water spray is about 1.5ft (500 mm).

I am worried about the temperature gradient between the furnace end and the water spray with consideration to the slow travel speed.

Now, Is ASTM A262, Practice E sufficient to ensure solution annealing of 316L stainless steel?
what if it was duplex SS ?

 

[EdStainless]

For duplex alloys the spec is A923.
It covers 3 methods and has acceptance criteria.
The concern with these alloys the formation of intermetallics.

My experience says that they could force air cool 316L and not get sensitization.
Just a caution, specifying practice E does not mean that you get the Sulfuric/CuSulfate test.
Spec one in Prac E says to do a micro and if it looks fine let it pass.

That speed sounds ridiculously slow. Even for material that thick.

 

[isoca]

The test according to A262 should give OK under any condition. Note that for 316L the test must be performed in sensitized condition.

 

[ShabsRBI]

As per SA-312 specification, the Practice A262 requires the test to be performed on sensitized specimens in the low Carbon and stabilized types and on specimens representatives of the as -shipped conditions for other types.

What does that statement means:

Does it mean that for low carbon and stabilized grade ( SS-316L) practice A262 is not applicable for as supply condition and only required post service or if any hot work is performed on the material?

 

[EdStainless]

It is applicable if you specify it.
And if you specify it then they will sensitize a sample, do a micro, and if there is any question they will proceed to do the corrosion test.

This test doesn't work well with high Mo alloys (317 and up).
The results can be hard to determine.