4340 nitrogen levels 2

[mcguire]

4340 has no nitrogen spec. Does anyone know a typical value?

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[metengr]

Based on information I have seen and a project that I was involved with regarding low alloy steel -

For BOF steels, typical range is 30-50 ppm

For EAF air melt, typical range is 40-120 ppm.

 

[TVP]

I concur with the ranges provided by metengr. If the 4340 goes through vacuum degassing after the ladle station in an EAF process, then definitely toward the low end, 40-70 ppm.

 

[arunmrao]

Just curious,why are you looking for Nitrogen in 4340 grade please?

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[mcguire]

Arunmrao
I'm doing some research on hydrogen embrittlement and hydrogen's interaction with dislocations. The dislocation density in martensite is a function of interstitial level, but some data I have for 4340 omits nitrogen level. So, in the VAR 4340 mentioned I will use the level suggested by TVP.
This gives a dislocation density of 1.5 x 10 (exp13)/cm2 if anyone is interested, as-quenched, of course.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[arunmrao]

As always, you deserve a star for your pioneering work.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[mcguire]

I still want to come see you!

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/