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.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
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
