在工厂无大型退火炉的情况下,对于未经正常化处理的25号热轧钢板,我们采用的是焊后正火的办法,使其达到《HB7—13—72》规定的标准。正火可以起到细化奥氏体晶粒、消除魏氏组织、消除轧制钢的带状组织和内应力的作用,从而提高其强度、塑性和韧性,改善钢的机械性能。该轧制状态原材料的原始组织(图1)呈魏氏组织(约2～3级),无明显带状组 In the absence of a large-scale annealing furnace in the factory, we adopted a post-normalizing method for No. 25 hot-rolled steel sheet that has not been normalized to meet the standard of “HB7-13-72”. Normalizing can refine the austenite grains, eliminate Widmanstatten, eliminate the effect of the banded structure and internal stress of the rolled steel, thereby enhancing its strength, ductility and toughness, and improving the mechanical properties of the steel. The raw material of the rolling state of the original organization (Figure 1) was Wei’s tissue (about 2 to 3), no obvious band group