图(a)为DZ2(0.17V0Nb)钢两次淬火后的奥氏体晶粒形貌,由图可知,奥氏体晶粒均为等轴晶粒,通过直线截距法统计奥氏体晶粒尺寸可知,DZ2(0.17V0Nb)钢两次淬火后的奥氏体平均晶粒尺寸分别为11µm,与一次淬火工艺下的奥氏体晶粒尺寸相比晶粒细化程度为63.3%。
Figure (a) shows the austenite grain morphology of DZ2 (0.17V0Nb) steel after quenching twice. It can be seen from the figure that all austenite grains are equiaxed. The average austenite grain size of DZ2 (0.17V0Nb) steel after quenching twice is 11µm, respectively. The grain refinement is 63.3% compared with the austenite grain size under the primary quenching process.