Cr12MoV钢的隐晶马氏体及其强韧化

Cryptocrystalline Martensites and Strengthening and Toughening of the Cr12MoV Steel

文章对Cr12MoV 钢的隐晶码氏体及其强韧化进行了研究。电镜分析表明,Cr12MoV 钢的淬火隐晶马氏体的微观形态与亚结构随淬火奥氏体化温度不同而异。950℃及其以下奥氏体化温度淬火,可获得单一的板条状位错融隐晶马氏体;而经950～1100℃奥氏体化温度淬火,则获得了由针(片)状孪晶马氏体与板条状位错马氏体构成的混合隐晶马氏体组织,并且孪晶马氏体随奥氏体化温度升高而增多。经机械性能试验发现,隐晶马氏体的微观形态与亚结构对钢的强韧性有直接影响。因此,为了使Cr12MoV 钢得到最有效的强韧化效果,不仅要均匀化和细化钢中的碳化物,而且要控制钢中隐晶马氏体的微观形态与亚结构。

The cryptocrystalline martensites and the strengtheming and toughening of the Cr12MoV steel have been invesigated.TEM examination showed that the morphology of the cry- ptocrystalline martensites and their substructures are changed with the different austenitizing ■peratures.The cryptocrystalline lath martensite with dislocated substructure was obtained by quenching from austenitizing temperature 950℃ below;but the mixed martensites which were com- posed of the cryptocrystalline lath martensite with dislocated substructure and the cryptocrystal- line needle-like(plate)martensite with twin substructure were observed after quenching from austenitizing temperatures range from 950℃,to 1100℃,and the needle-like(plate)martensite with twin substructure grew in quantity uhen the austenitizing temperature was going up.It was found that by mechanical property tests,the morphology and the substructure of the cryptocrysta- lline martensites were having a direct influence on the strength and toughness of the Cr12MoV steel.In order to attain the strengthening and.the toughening of the Cr12MoV steel,it is neces- sary not only to make the carbide homogeneons and refined,but also to control the morphology and the substructures of the matensite.