| 摘要 |
PURPOSE:To obtain at a low cost, a hot rolled steel plate good in workability utilizing the reserved heat of slab, by a method wherein the hot slab continuously casted by low alloy steel of a fixed composition is rolled under specified conditions without decreasing its temperature, then charged into a reheating furnace and thereafter hot-rolled. CONSTITUTION:The steel consisting of 0.10% max. C, 0.50% max. Mn, 0.10% max. Si, 0.020% max. P, 0.015% max. S, 0.01-0.09% Al, remainder Fe and inevitable impurities, is continuously cast. This hot slab is rolled by 5-30% reduction at Ar3-1,200 deg.C without decreasing temperature to Ar3 point max, MnS being precipitated, coarsened in low temperature heating and softened. At the same time, the site for precipitation of AlN is inducted and the precipitation and coagulation are achieved in heating at a low temperature. After heating it by charging it into a reheating furnace kept at 950-1,150 deg.C successively from this reduction, it is processed by fixed hot rolling. By this method, the hot rolled steel plate for processing can be obtained by little thermal consumption. |
