HIGH-CARBON AND SILICON-CONTAINING ULTRA-HARD SUPER-TOUGH HIGH-SPEED STEEL

摘要

The present invention concerns a high-carbon and silicon-containing ultra-hard super-tough high-speed steel and heat treatment process thereof. The composition of the steel is (in wt%): C 0.6-1.1, W 5.50-6.75, Mo 4.50-5.50, Cr 3.80-4.40, V 1.75-2.20, Mn 0.15-0.40, S ≤0.03, P ≤0.03, Si 0.8-1.2, and balanced Fe. The heat treatment process includes: quenching at 1180-1220 , followed by triple tempering at 550-560 , 1-2 hrs for each; and the steel with a carbon-content of 0.6-0.85% needs to be subjected to super-saturation carburization prior to quenching so as to reach a carbon-content of 0.95-1.10% at the surface. The present invention could make products low in price and good in strength and toughness, with a hardness up to 67±1 HRC after heat treatment.