| 摘要 |
<p>PURPOSE: To provide an advantageous effect of improved machinability and grindability by hot working the particles of a tool steel alloy of specific sulfide size and sulfur content and forming a fully dense and consolidated mass. CONSTITUTION: The nitrogen-gas-atomized and prealloyed particles of a tool steel alloy having <=15μm maximum sulfide size and 0.10 to 0.30 wt.% sulfur content are hot worked into a fully dense and consolidated mass, by which a machinable powder-metallurgy produced sulfur-containing tool steel article is formed. The tool steel alloy has a composition consisting of, by weight, 0.80-3% C, 0.20-2% Mn, 0.10-0.30% S, <=0.04% P, 0.20-1.50% Si, 3-12% Cr, 0.25-10% V, <=11% Ho, <=18% W, <=10% Co, <=0.10% N, <=0.025% O, and the balance iron with incidental impurities. By this method, the serious adverse effect of sulfur and occurring sulfide on mechanical properties can be prevented.</p> |
