Summary for nitrogen quenching 316l Discussion
Nitrogen quenching for 316L stainless steel is discussed as an alternative to water quenching after annealing an investment-cast component. The questioner, Joseph Caron of Paramus, New Jersey, asked whether a supplier’s proposal to quench in nitrogen would be acceptable for reaching 75-85 HRB instead of water. The answer says nitrogen quenching is a common practice after annealing stainless steels, especially after vacuum annealing. The important requirement is not the medium itself but that the parts cool rapidly through roughly 1600F down to below 800F. If nitrogen can do that within a few minutes, it should be acceptable; very large parts may be a concern. The response also notes that hardness will not be significantly affected by cooling rate, and that rapid cooling is mainly needed to avoid sensitization and preserve corrosion resistance.
Q. I have an application for annealing a Investment Cast 316L S.S. component and then water quenching to achieve a hardness of 75-85 hrb.. The supplier is proposing to Quench in Nitrogen.
Please advise if this is acceptable as opposed to Quenching in water?
Joseph Caron
– Paramus, New Jersey
2001
A. Nitrogen quenching is a common practice following annealing of stainless steels, especially for vacuum annealing. The key to the stainless steel quench is to cool the parts rapidly through the temperature range from about 1600F down to below 800F. If the nitrogen quench can accomplish this for your parts within even a few minutes, you should be OK. I would expect a problem only for very large parts. The hardness will not be affected significantly by the cooling rate. The fast cooling is to avoid sensitization and maintain optimum corrosion resistance.
Larry Hanke
Minneapolis, Minnesota
2001
Q. Hello, I am looking for information with respect to annealing of 316L and quenching it very fast with Argon. Do you have any information about this topic.
Kind regards
Hub Merx
– Kerkrade, Limburg, Netherlands
December 19, 2012