| 摘要 |
PURPOSE:To obtain a composite tool steel for hot working which is improved in durability by 2-10 times of the level in the prior art, by allowing the powder, plate or the like of an alloy to present on the surface of a steel blank material contg. C, Si, Mn, Cr as essential components, and irradiating a laser beam thereto to melt the surface layer part. CONSTITUTION:A steel blank material contg., by wt%, 0.2-2.0% C, 0.1-1.5% Si, 0.1-2.0% Mn, and 0.5-20% Cr as essential components, and contg. >=1 kinds among 0.5-10% Ni, 0.2-2% Mo, 0.1-1% V, 0.1-1% Nb, and 0.1-1% Ti is prepd. The powder, plate or bar of an alloy is allowed to present on the surface of such steel blank material by coating, adhering or the like, whereafter a laser beam is irradiated to the surface to melt quickly the surface layer alone. Thereafter, the surface layer is quickly cooled by the extraction of heat from the unmolten part of a low temp. around the molten metal, whereby the composite tool steel in a 0.1-10mm. thickness range for hot working contg. 1- 35% C and 1-25% Cr as essential components and further contg. >=1 kinds among 0.5-15% Ni, 0.2-5% Mo, 0.2-3% Co, 0.1-3% W, etc. in the chemical components is obtd. |
