Nitrogen in Steel
Nitrogen in Steel
(OP)
I notice in many of the duplex steels, and alloy steels, higher concentrations of nitrogen are used (say 0.2-0.3%). As a Chemical Engineer, I can't comprehend how gasious nitrogen can stay in solution of steel at 2000F. Boiler Feedwater is stripped essentially all of its O2 and N2 (50 ppm) at 300F.
Can someone explain how that much nitrogen stays in the steel during a 2000F manufacturing process.
Thanks
Can someone explain how that much nitrogen stays in the steel during a 2000F manufacturing process.
Thanks





RE: Nitrogen in Steel
RE: Nitrogen in Steel
RE: Nitrogen in Steel
RE: Nitrogen in Steel
In austenitic steels or in the austenite phase of duplex stainless steels, nitrogen is quite soluble. At atmospheric pressure of nitrogen, 304 is at equilibrium when it has about 0.25% nitrogen at solidus temperature.
Manganese ehhances nitrogen solubility as does molybdenum.
So you really don't have to try hard to keep the nitrogen in. In fact, it would take a vacuum treatment or flushing the molten metal with inert gas to get it out.
RE: Nitrogen in Steel
We add nitrogen into our steels using nitrided ferro-chrome, which typically contain 3% or 6% nitrogen. We are induction melting, in air, and our losses aren't that great.
RE: Nitrogen in Steel
Unfortunately this is not available in India and I do not know if anyone would be interested in supplying small batch quantities. Please try and help me in sourcing this material.
RE: Nitrogen in Steel
As a stupid chem. ing., heavily infected by mechanics, I am theoretically interested in the process of making nitrided ferro-chrome. If it is similar to nitriding steel, so the process seems to be rather simple, it can be easely accomplished practically anywhere.
Best regards Andras
RE: Nitrogen in Steel
How small is a small quantity?
I will make enquiries and see if anybody here in the UK can make any suggestions. Perhaps somebody nearer to you than I am may have an idea - any Australians or Japanese out there who can help??
RE: Nitrogen in Steel
Bruv
RE: Nitrogen in Steel
Arunmrao (if you see this - you didn't mark the thread)
I've had a word around and most nitrided FeCr in this part of the world comes from one of two sources, either South Africa or Germany. The South Africans are at Middleburg Steel & Alloys, but I've not yet found a decent link to them. Links you might find useful are: www.aimcornet.com/metalagentxt3.htm (South Africa) www.hernic.co.za. (South Africa)www.elektrowerk.de/en/index2.html (Germany)
Hopefully one will be able to help
Best of luck
Bruv
RE: Nitrogen in Steel