How to control or increase passive file in stainless steel

[Best99]

I would like to know about method or process that can control or thicken passive film in stainless steel. When i search it from Google, there are informations talked about anodizing or electro polishing but these method used for non ferrous metal like aluminium,titanium etc. not stainless steel.

Thank you for kindly suggestion

 

[arunmrao]

"Passivation of stainless steel" by Dan Englebert

http://chemistry.about.com/gi/dynamic/offsite.htm?site=http://www.pfonline.com/articles/119806.html

 

[UconnMaterials]

Bodyslam,

Passive films are typically very thin (< 10nm). The thickness is controlled by diffusion, which is why they are thin when the passivation process is done at room temperature.

Best Regards,

Uconnmaterials

 

[mcguire]

The most corrosion resistant stainless alloys have the thinnest passive films, not the thickest. The reason is that their higher alloy contents permit the faster formation of Cr-rich layers. Use bases and acids like nitric to remove iron oxides and permit the Cr-rich layer to form without competition. The absence of halides is important because they undermine the Cr-OH bonding.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/