基于响应面法的枝杈类锻件挤压成形折叠缺陷参数化研究

Study on parameterization of folding defects in extrusion forming process of branch forgings based on response surface method

以枝杈类锻件挤压成形过程中枝杈根部产生的折叠缺陷为研究对象,采用数值模拟、响应面法及试验相结合的方法进行研究,将影响折叠缺陷程度最大的3个参数,即挤压速度v、冲头底锥相对直径d/D和模具圆弧外端与冲头环形平面距离h作为设计变量,建立了枝杈根部最大折叠长度Llap的目标函数关系式。研究结果表明,增大挤压速度v、模具圆弧外端与冲头环形平面距离h以及减小冲头底锥相对直径d/D均可减小折叠长度,并且对最大折叠长度Llap影响的主次顺序为d/D>h>v。试验结果与数值模拟结果均验证了Llap函数表达式的正确性,3种方法所得最大折叠长度误差为5.44%~15.02%。

In view of the folding defect at branch roots in the extrusion process of branch-type forgings,the combination method of numer-ical simulation,response surface method and experiments was carried out.The function expression of the maximum folding length Llap at the branch roots was established considering the three factors that have the maximum degree on folding defect as the design variables inclu-ding extrusion speed v,relative diameter d/D of the punch base cone and the distance h between outer end of the die arc and annular sur-face of punch.The results show that by increasing the extrusion speed v and the distance h,or decreasing the relative diameter d/D,the folding length can be reduced obviously,and the influence level on the maximum folding length is d/D>h>v.The Llap function expression was verified by the numerical simulation and experiment results,and the maximum length error of the three methods is 5.44%-15.02%.