passivation

By js55

Date 03-29-2011 16:39

After. Not much point before.

By TimGary (****)

Date 03-29-2011 18:15

Definately after.
The purpose of the passivation is to rejuvinate the microns thick chromium layer on the outside of the material, where it has been damaged through handling and welding, in order to maximize corrosion prevention properties.

Tim

By Milton Gravitt (***)

Date 03-29-2011 18:43

Thanks guys.

M.G.

By James Kelly Date 04-17-2011 21:23

Strictly speaking, stainless steel "passivates" in air.

Chemical or mechanical treatment after welding is to remove any imbedded iron, from assorted steel or cast iron machine parts, as well as to remove heat tint (of course, your inspector/customer may or may not agree with me).