ASTM A967 NITRIC FOR WELDED ASSEMBLY

[mdthurwitz]

Hi all

I need to passive a welded assembly (ss304 welded to ss303)
can any one recommend the right nitric process (1,2,3,4 ) per the A967?
pros/cons etc...

any info will be helpful

thanks!

 

[unclesyd]

First off your metal combination is odd and I/m a little amazed that you got a metallurgical a bond with any strength with the 303 SS. In the HNO3 pickling solution the 303 SS can corrode quite rapidly, it will get smutty.
303 SS is not amendable to passivation with any solution. If aesthetics isn't a problem a heat tint in an oxidizing atmosphere will give you some protection, not much.