Method for hardening steel

Details Method for hardening steel Method for hardening steel

1981-03-20

1982-12-28

Sheehan, John P.

Metal treatment

Process of modifying or maintaining internal physical...

Chemical-heat removing or burning of metal

148 124, 148 203, C21D 118

Patent

active

043660088

ABSTRACT:
A method of hardening steel so that it may have a surface layer with sufficient hardness to permit fabrication into machinery parts with a minimum of strain developed therein. The method comprises heating steel at a temperature in a range not lower than 100.degree. C. below its A.sub.1 transformation point (about 630.degree. C.) and not higher than 50.degree. C. thereabove (about 780.degree. C.) in an atmosphere consisting solely of ammonia gas, or composed of ammonia gas and at least one of organic liquids, petroleum gases, endothermic gases and neutral gases, while ammonia gas is being supplied continuously at a lower flow rate, or at a higher flow rate followed by a diffusion treatment to austenitize a surface layer of the steel by penetration of nitrogen thereinto, and quenching the steel to transform the austenitized surface layer into a martensite layer.

REFERENCES:
patent: 2339223 (1944-01-01), Holt
patent: 3137596 (1964-06-01), Unterweiser
patent: 3265541 (1966-08-01), Elias
patent: 3282746 (1966-11-01), Zlotek
patent: 3357869 (1967-12-01), Shepeljakousky
patent: 3647572 (1972-03-01), Todd et al.
patent: 3705058 (1972-12-01), Kolozsuari et al.
patent: 4047981 (1977-09-01), Arnold et al.
patent: 4124199 (1978-11-01), Jones et al.
patent: 4145232 (1979-03-01), Solomon

Affiliated with

Also associated with

Rating

Method for hardening steel does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method for hardening steel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for hardening steel will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1335908