30CrMnSiA钢板表面塑性损伤的细观机理研究

MESOMECHANISM OF DUCTILE DAMAGE ON THE SURFACE OF 30CrMnSiA STEEL PLATE

采用单向拉伸试样，研究了３０ＣｒＭｎＳｉＡ钢板分别沿轧制、宽度两个方向拉伸时表面塑性损伤的发展规律。通过扫描电子显微镜观测表明，表面塑性损伤的细观机理是表面空穴形核、扩张和聚合的过程。随着塑性应变的增大，表面空穴的形核是按多级规律进行的，其总体平均意义下的面积百分数是单调增长的，且增长的速率逐渐加快。文中还提出一个表征板材抗表面损伤特性的材料参数。

The mesomechanism of ductile surface damage has been investigated by use of the tensile specimensmade of the 30CrMnSiA steel plate both longitudinally and transversely. The results of observation undter thescanning electron microscope show quantitatively that the growth microprocess of ductile surface damage includethe nucleation,growth and coalescence of surface voids. With the increasing of plastic strain,the microvoid nucleation is multistage,but the area fraction of growing voids raises monotonously. Then a material parameter for theresistance of ductile surface damage has been suggested based on the void density curve.