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Passivation of 440

What is the best passivation process for 440c?

Dave Mortenson
Pullbrite, Inc. - Fremont, California USA
2000

Electropolishing is considered the best way to passivate stainless steel. What particular application did you have in mind?

Tom Pullizzi
Falls Township, Pennsylvania
2000

2000

We use the Type 8 formulation found in AMS2700, which is the same as the Type VIII found in the olde QQ-P-35C [link is to free spec at Defense Logistics Agency, dla.mil]. 45-55% nitric acid in water, 120-130F, for 30 minutes minimum. We don't use a chromate dip afterward.

Lee Gearhart
metallurgist - E. Aurora, New York

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