脉冲电流对疲劳后30CrMnSiA钢组织结构的影响  

Effect of electropulsing on the fatigued heat-rolled 30CrMnSiA steel

作　　者：吕宝臣[1,2] 周亦胄 王宝全[1,2] 郭敬东 

机构地区：[1]中国科学院金属研究所 [2]沈阳材料科学国家(联合)实验室

出　　处：《材料研究学报》2003年第1期15-18,共4页Chinese Journal of Materials Research

基　　金：国家自然科学基金No.59931020;50141002;国家重点基础研究发展规划基金G1999065009

摘　　要：对在应力控制下预疲劳卸载的热轧态30CrMnSiA钢样品进行高密度脉冲电流处理后,得到了细小均匀的等轴晶组织,晶粒尺寸远小于热轧样品的晶粒尺寸。处理后样品的疲劳寿命显著提高。高密度脉冲电流使疲劳形成的位错产生运动,当刃型位错的距离达到临界距离时,位错发生湮灭,使局部的位错密度梯度增大,在位错密度低的地方发生再结晶形核,使钢发生再结晶。Pre-fatigued heat-rolled 30CrMnSiA steel sample was treated by high density electropulsing, then fine and uniform equiaxed grain was obtained and grain size was much fine than that of the original sample. The fatigue life of samples was prolonged after treatment. It is supposed that the dislocations moved when suffering electropulsing, a dipole consisting of edge dislocations of opposite sign will annihilate to form a vacancy when spacing of the edge dislocations became smaller than critical spacing. The increase of the local dislocations density gradient causes the recrystallizing nucleus to be formed in the lower dislocation density regions.

关 键 词：脉冲电流 30CRMNSIA钢 组织结构 疲劳 晶粒细化 脉冲电流处理 再结晶 

分 类 号：TG156.99[金属学及工艺—热处理] TG142.1[金属学及工艺—金属学]