PRODUCTION OF HOT ROLLED PLATE OF HIGH TENSILE STRENGTH STEEL EXCELLENT IN FATIGUE CHARACTERISTIC

摘要

PURPOSE: To control the fatigue limit ratio of a starting plate to ≥0.5 and to maintain superior fatigue characteristics even after performing baking aging treatment, etc. ;CONSTITUTION: At the time of producing a hot rolled plate of high tensile strength steel, a continuously cast slab having a composition containing, by weight, 0.05-0.20% C, 0.50-2.00% Si, 0.50-2.00% Mn, ≤0.01% Al, and 0.003-0.020% N is reheated up to 1050-1250°C and hot rolling is finished at a temp. in the range between Ar₃ and (Ar₃+100)°C. Then the resulting plate is cooled down to ≤400°C at ≥30°C/sec average cooling rate and coiled.;COPYRIGHT: (C)1994,JPO&Japio