| 摘要 |
PURPOSE:To produce a hot rolled wire rod of a high-Si steel which obviates generation of a disconnection and internal defect by heating the high-Si steel to a specific temp., hot rolling the steel to form a wire rod and cooling the wire rod at a specified average cooling rate. CONSTITUTION:The high-Si steel contg. by weight, about 0.5-0.7% C, about 1.0-1.8% Si, about 0.1-1.0% Mn, about 0.3-0.6% Cr, 0.030-0.250% V, and the balance iron and unavoidable impurities, and contg. one kind among 0.020-0.100% Al and 0.02-0.1% Nb at need is heated to 950-1,050 deg.C and is hot rolled to form the wire rod. The wire rod is quickly cooled down to about 700-800 deg.C to prevent the formation of coarse ferrite crystal grains. After the cooled wire rod is coiled on a coiler, the wire rod is cooled down to the transformation end temp. (Ar1) at about 2-3.5 deg.C/sec average cooling rate and is then allowed to cool. The wire rod which does not generate chevron cracks in drawing work and obviates the generation of the disconnection and internal defect is thereby obtd. |
