中碳钢高温形变热处理强化机理探讨

ENHANCEMENT MECHANISM OF DEFORMATIVE HIGH TEMPERATURE TREATMENT OF MEDIUM CARBON STEEL

经比较高温形变热处理反常规热处理后的55SiMnVB 钢55碳钢的力学性能及组织结构,本文得出了形变强化的原因:形变使位错密度增加及形成稳定的位错亚结构,改变了碳化物的析出和分布以及孪晶结构所处的位置。而形变织构及晶粒的细化,不是形变强化的主要原因。晶粒细化对材料的塑韧性有着较大的影响。

Cause for deformative ative enhancement is concluded after a comparison between the mechanical properties and metallography of 55Si MnVB steel and 55 carbon steel:It is deformation that increases the den- sity of dislocation and leads to a stable dislocated sabstrueture both of wh- ich alter the segregation and distribution of the carbide and the location of the twin crystalline structurc.But the deformed texture and the reduc- tion in grain size are not important to deformative enhancement.How- ever,the reduction of grain size has,to a certain extent,an effect on the plastic toughness of the material.