Hardenable alloy steel powder contg. manganese - and with low oxygen content so dense, high strength powder forgings can be obtd.

摘要

The alloy comprises by wt. 0.1-0.7% C; 2% max. Ni; 1% max. Mo; 0.2-1.75% Mn; 0.04-1.51% Cr; 0.1% max. Si; 5000 ppm. max. O2; balance iron. Pref. alloys contain (a) 0.2-0.6% C; (b) 0.04-0.8% Cr; (c) 0.55-1.75% Mn; (d) 1.8% Ni; (e) 0.25% Mo. The pref. annealing treatment is at 750-1200 degrees C in a reducing atmos., esp. H2 or cracked ammonia. Used as e.g. powders for sintering and/or forging, where a high carbon content is present, not only to assist hardenability but also to maintain a low oxygen content so the porosity of the final product, e.g. a forging, is reduced, and the mechanical properties improved. With a low O2 content the oxidn. of the Mn present is avoided.