Pitting Performance - 304 vice 304L

[mshimko]

Does anyone have data or thoughts on the pitting performance of Type 304 stainless steel versus Type 304L?
Are they expected to be similar, or is one significantly different?

 

[NickE]

They should (if the non-low carbon matl' isn't sensitized) be exactly the same.... (AFAIK, but mcguire will be along, or maybe even edstainless)

 

[metengr]

mshimko;
From the reference "Corrosion of Stainless Steels" by John Sedricks, there is a table (page 120) that summarizes the effects of elements on the pitting resistance of austenitic stainless steels in chloride solutions. The effects are either beneficial, variable, no effect, detrimental or not investigated.


Agree with NickE. For carbon, the effect on pitting resistance is listed as variable. Carbon would have no effect on pitting resistance in solid solution unless it is precipitated as a carbide.

 

[EdStainless]

IF everything else is equalthey will be the same.
Often you find that lower C heats also have higher N. This leads to higher pitting resistance. You can't really measure it unless you are doing electrochemical work because the efefct is slight and 304 doesn't have much pitting resistance to start with.
The only other chemistry factors to look at are the Cr and Mo. Some 304(L) heats have a lot of residual Mo which helps pitting, but it isn't something that you can sound on.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[mshimko]

Thanks for all your comments. My issue was evaluating 304 in a soil environment with limited data, and I found a study in the same area that used 304L. I was hoping I was justified in using the 304L data since sensitization & intergranular corrosion don't come into play (at least I hope not).

0.