Chemical reacation of 201 stainless steel

[tsutter]

Is 200 series stainless steel more likely to rust when exposed to Iodine, or dishware detergent, than 300 series stainless steel? The seam are welded with 200 series rod and wire brushed to clean up the color.

 

[mcguire]

That depends. The only thing that counts is chromium, nitrogen and molybdenum, not nickel. So, as a generality 200's and 300's are not different.

That having been said, people usually think 201 for 200 series and 304 for 300 series. 304 has 18% Cr and 201 has only 16%, so 201 is at a slight disadvantage.

There are lots of dishwashers and washing machines made with both grades and they both work fine. Just make sure the welds are low sulfur and that there is no sensitization.
Don't leave any crevices.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[EdStainless]

It is good practice to make sure that your weld filler for 201 is slightly over alloyed. I have seen some 201 that would result in higher ferrite numbers, which would make the welds less corrosion resistant in low pH environments.

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Plymouth Tube

 

[strider6]

the SS200 has been developed as a cheaper substitute of the SS 300 (instead of Ni there is more Mn). The corrosion resistance of SS200 is generally lower than that of SS304.

http://www.worldstainless.org/NR/rd...F53504A87667/3265/200seriesstainlesssteel.pdf

"200 Series Stainless Steel

Most growth in 200-series use over recent years has been in low-nickel and therefore lowchromium versions which have less corrosion resistance than grade 304. The end result has been corrosion failures in some applications and dissatisfied customers."

http://www.worldstainless.org/About+stainless/What+is/Categories/200+Series+Stainless+Steel.htm

“New 200-series” steels:An opportunity or a threat to the image of stainless steel?

http://www.worldstainless.org/NR/rd...iessteelsAnopportunityorathreattotheimage.pdf

S

Corrosion Prevention & Corrosion Control

 

[mcguire]

Guys
Do not blindly accept the propaganda that nickel company-funded organizations pump out. I can personally cite case after case of successful conversion from 304 to 201. The only problem people have had is getting service centers to stock it.
There is simply no need to use more nickel than absolutely necessary.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/