锻造理论与工艺的进展

Development of Forging Theory and Technology

塑性加工原理中，在镦粗工艺理论方面，发现、提出与研究了平板间镦粗圆柱体的新理论。在此基础上，提出了广义滑移线法和力学分块祛。为了克服平板激粗时其镦粒体内变形不均匀与应力状态不佳的两大缺陷，从改变毛坯端部的边界条件入手，提出了一种新工艺──锥形板镦粗。在拔长工艺理论方面，应用方柱体镦粗的两个新力学模型与拔长的刚端影响问题，论证了只有砧宽比一个工艺参数的不足，而应补充一个新的工艺参数──料宽比，才能正确描述拔长体中心区域的应力状态与有效控制锻件质量，并进一步解决了该拔长理论工艺参数量值的合理匹配与确定，在“锻造条件对毛坯内部空洞闭合的影响”研究中，提出了增加料宽比对横向拉应力控制的“新FM（FreefromMannesmanneffect）法”。并在此基础上提出了横向无拉应力锻造法。用上述理论指导工艺生产，可大幅度提高锻件的质量。

In plastical processing mechanics, on upsetting, anew theory for upsetting a cylinder between two flat platens isdiscovered, proposed and studied. Based on this, generalizedsliding line method and mechanical apart method are put for-ward. To overcome the uneven distribution of deformation andthe unsatisfied stress state in the internal of flat platens upset-ted blanks, a new theory, V-shaped die upsetting is broughtforward, considering the boundary condition of the blank end.On stretching, tWo new mechanical models for upsetting blankwith square cross section and the rigid end effecting instretching proved that only one technological parameter, thetool width ratio, is not sufficient to describe the internal stressstate correctly and to control the quality of forgings effectively,and another parameter, blank width ratio, should be added.The matching and decision of Stretching technological parame-ters axe solved. In researching the effect of forging conditionson closing the internal cavities, new FM (Free from Ma-rmesmann effect) method with the adding of blank width ratioto control crossing tensile sbess is proposed, accordingly thefree from crossing tensile stress forging method is also advan-ced. All the abovc mentioned theories can, to a large extent,improve the quality of foreings if they were used in decidingtechnology.