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Making AISI 420 as corrosion resistant as 304

I have some machined part made of material AISI 420. How can I can get corrosion resistance for the same? By passivation, or coating etc? I want to have corrosion resistance equivalent to AISI 304.

Chirag Patel
- Mumbai, Maharashtra, India

Passivating 420 alloy using a non nitric acid passivating solution will improve corrosion resistance but will not compare to corrosion resistance of 304.

Electroless nickel plating 420 with a high phosphorous nickel alloy will greatly improve the corrosion resistance. 18-25 micron thickness will provide maximum protection but service environment will determine if electroless nickel is comparable to 304 stainless.

Dayton Dailey
- Lake Zurich, Illinois, USA

I agree with Dayton on this. You can NEVER make 420 corrosion resistant steel as good as 304 stainless steel unless you coat it. Electropolishing will help a lot, also; but it will never be 304.

lee kremer
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Lee Kremer
Stellar Solutions, Inc.
supporting advertiser
McHenry, Illinois
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The corrosion resistance of 300 series SS is superior mainly because of the presence of nickel, which 400SS steels do not have. Anything you put on top will not change the chemical composition of the base metal and will protect it according to its own nature, imperviousness, adhesion and thickness. Thickness being equal EN is even better than plain 300 SS, but then again, how thick would the plate have to be to compete against an equivalent part made of solid 300 SS?

G. Marrufo-Mexico

Guillermo Marrufo
Monterrey, NL, Mexico

Electroless Nickel plating does substantially improve corrosion resistance. How does this plating perform for surface adhesion, particularly when it is moving in jig guides in surgical applications?

Narendra Damle
surgical equipment - Pune, Mah., India
September 3, 2009

September 2009

Hi, Narendra. This should not be an issue at all. Electroless nickel is applied to all sorts of parts, including machinery parts.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

August 26, 2011

Thank you Ted. We did have some adhesion issues initially, but after process improvements those were resolved. Is EN plating allowed for surgical cutting applications?

What is the best pickling-passivation process of AISI 420?


Narendra Damle
- Pune, Maharashtra, India

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