Thomas F Kinneman

US Patent:

41393759, Feb 13, 1979

Filed:

Feb 6, 1978

Appl. No.:

5/875615

Inventors:

Jack Solomon - Rye NY
Thomas F. Kinneman - Peekskill NY

Assignee:

Union Carbide Corporation - New York NY

International Classification:

B22F 300

US Classification:

75224

Abstract:

In a process for sintering powder metal parts comprising: (a) passing the parts through a furnace adapted therefor from its upstream end to its downstream end, said furnace having two successive zones, an upstream zone, which is maintained at a temperature in the range of about 800. degree. F to about 2200. degree. F and a cooling zone, said furnace further having an atmosphere therein comprising carbon monoxide, hydrogen, carbon dioxide, water and nitrogen distributed throughout the zones; (b) permitting the parts to reside in the upstream zone for a sufficient length of time to cause sintering; and (c) removing the sintered parts from the furnace, the improvement comprising: introducing a mixture consisting essentially Of methanol and nitrogen into the upstream zone at a point where a temperature of at least about 1500. degree. F is maintaied, the methanol and nitrogen being in a ratio sufficient to provide, when subjected to such temperature, an atmosphere comprising, in percent by volume, about 1 to about 20 percent carbon monoxide; and about 1 to about 40 percent hydrogen; and balance nitrogen.