30Cr MnSi A钢亚温淬火时组织形态的观察

研究了30CrMnSiA钢亚温淬火前原始组织及加热速度对亚温淬火所获复合组织形态的影响,亚温淬火可获得针状,颗粒状和类针状复合组织,各种形态的复合组织中,未溶铁素体均分布于奥氏体晶界上,对加热保温过程中奥氏体的晶粒长大起阻碍作用,类针状复合组织中的铁素体和奥氏体晶粒的尺寸均比大颗粒状复合组织的细小,而与小颗粒状复合组织的相当,因此,与具有最佳强韧性的针状复合组织相比较,类针状复合组织的获得将有可能在保证强韧性不降低的条件下,简化热处理工艺。

Morphologies of steel 300 MnSiA during Intercritical Heat-Treatment(IHT)

The effects of original structure and beating rate on the morphology of steel 30CrMnSiA are studied. Acicular F+M complexed structure, granular F+M complexed structure and like-acicular F+M complexed structure are gotten during IHT. The remained F is always distributed on the grain boundary of the original A in all the structures mentioned above, and the F retards the growth of A grains. The grain sizes of F and A in like-acicular structure are smaller than those in the coarse granular F+M complexed structure and are the same as those in the fine granular F+M complexed structure. Compared with the acicular complexed structure which is good in strength and toughness, the like-acicular complexed structure is to be obtained and has no loss of strength and toughness.