Does passivation help against Chromium Carbide precipitation?

[trainguy]

All,

2 questions:

1) Is it possible to get chromium carbide precipitation in a low-carbon stainless steel grade, such as AISI 301LN?

2) Will passivation of 301LN stainless prevent carbide precipitation?

Thanks!
tg

 

[TugboatEng]

Carbide precipitation is a heat issue. The material needs to be annealed and rapidly quenched to prevent carbide precipitation. Surface treatments will not correct carbide precipitation.

 

1) After a very long period of time. But SS with carbon content less than 0.020% is immune for all practical purposes. Add Nitrogen and you may have Cr2N precipitation, but I haven't encountered that in any literature. Process this alloy with due attention to time at temperature and this steel's corrosion resistance will be alright (and because it is L grade, unlikely to be specified for high temperature service where damage can happen).
2) No. The two phenomena are unrelated.

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