| 摘要 |
PURPOSE:To obtain a high performance tool steel having excellent toughness, durability, abrasion resistance, etc. by adding >=1 kind of rare earth elements (REM) into slag or/and a consumable electrode, and performing electro-slag refining. CONSTITUTION:>=1 kind of REMs are added into slag or/and a consumable electrode so as to be incorporated at 5-20wt% in the slag, and electro-slag refining (ESR) is performed, whereby a tool steel is produced. The content of REMs in the steel material by said refining is adequately about 0.0005-0.6wt%. The steel ingot obtd. by using the above-mentioned method has an extremely good casting surface and is free from slag sticking, besides it has characteristics described in PURPOSE. Since the ingot thereof has excellent hot workability and a good surface, it exhibits an extremely high yield of production and is advantageous particularly as a material for high speed tool steel and cold die steel having a low yield of hot working. The REMs to be added into the slag are preferably REM oxides or/and REM fluorides, for which, for example, REM2O3, REM.F3, etc. are more preferably used. |
