| 摘要 |
<p>PURPOSE:To produce a steel with a fine structure high in toughness and ductility by subjecting an intermediate forming material, obtd. by subjecting a carbon steel or a low allay steel having a specified carbon content to rough rolling, to finish rolling in which the surface temp., working temp. and working strains are specified. CONSTITUTION:An intermediate forming material obtd. by subjecting the slab of a carbon steel contg. 0.6 to 10% C to hot rolling is heated or cooled to 850 to 1050 deg.C surface temp. and to the working temp. T ( deg.C) at which the final target gamma grain size in the curve of the working temp.-the size number of boundary recrystallized grains is found by the formula I:T50XN+1380+ or -30; where N denotes the target gamma grain diameter. Successively, it is subjected to finish rolling into a final product shape by working strains (e) readable from the finish rolling temp. in the curve of the working temp.-boundary recrystallized strains found by the formula II: e=-0.002XT+2.15+ or -0.04. Thus, the high carbon steel with a target fine pearlitic structure can be obtd.</p> |
