锻造过程中大截面塑料模具钢中空洞缺陷的闭合行为

Closure Behavior of Void Defects in Large-section Plastic Mold Steel during Forging

采用有限元法模拟了大截面塑料模具钢的锻造过程,采用代表体积元(RVE)模型模拟了锻造过程中模块内空洞缺陷的闭合行为。单个空洞的闭合行为表明:位于模块大变形区的P1点空洞在锻造过程中闭合,位于模块小变形区和难变形区的P2和P3点空洞仍保留0.62和0.65的相对体积。空洞缺陷的交互作用表明:水平排布空洞的闭合行为与单个空洞的一致,竖直排布空洞的闭合效率远低于单个空洞,P1、P2和P3点空洞的体积减小率比单个空洞分别缩小了52%、20%和10%;随着空洞间距的增大,水平排布空洞的闭合行为保持一致,而竖直排布空洞的闭合效率与单个空洞的闭合效率趋于接近,间距为0.01~0.05 mm的空洞的体积减小率分别为单个空洞的52%、65%、70%、76%和78%。载荷方向是决定空洞交互作用的关键,空洞取向和位置排布对空洞交互作用的影响程度相似,且均小于载荷方向的影响。

Finite element method was applied to simulate the forging process of large-section plastic mold steel,and representative volume element(RVE)model was adopted to simulate the closure behavior of void defects in the module during forging.The closure behavior of single void showed that the void defect at P1 point in the large deformation area of the module was closed during forging,while the void defects at P2 and P3 points in the small defomation area and hard-to-deform area of the module still retained a relative volume of 0.62 and 0.65.The interaction behavior of void defects showed that the closure behavior of void defects of horizontal arrangement was consistent with that of single void defect,while the closure efficiency of void defects of vertical arrangement was far lower than that of single void defect,and the volume reduction rates of void defects at P1,P2 and P3 points were 52%,20%and 10%smaller than those of single void defect,respectively.With the increase of void spacing,the closure behavior of void defects of horizontal arrangement was consistent,while the closure efficiency of void defects of vertical arrangement was similar to that of single void defect,and the volume reduction rates of void defects with spacing of 0.01 to 0.05 mm were 52%,65%,70%,76%and 78%of single void defect,respectively.The load direction was the key to determine the interaction behavior of void defects,and the influence of void orientation and location arrangement on their interaction behavior was similar and lower than that of loading direction.