图(a)和(b)为DZ2(0.17V0Nb)加热到850℃、900℃保温1h,油淬,然后在675℃回火4h,其显微组织的OM形貌。由图可知,DZ2(0.17V0Nb)钢组织为回火马氏体,部分马氏体板条已发生回复,且试验钢在900℃保温1h获得的组织更粗大。
Figures (a) and (b) show the OM morphology of the microstructure of DZ2 (0.17v0Nb) heated to 850℃, 900℃ for 1h, oil quenched, and then tempered at 675℃ for 4h. It can be seen from the figure that the microstructure of DZ2 (0.17V0Nb) steel is tempered martensite, and some martensite slat has recovered, and the microstructure of the test steel is thicker after holding at 900℃ for 1h.