RESEARCH ON HOT FORMING PROCESS OF A RETAINING RING OF HIGH-NITROGEN STEEL

Mn18Cr18N, the high-nitrogen steel, is the 2nd generation material for manufacturing the retaining ring of firepower generators. In this paper, the hot deformation behavior of the material was investigated by thermo-mechanical modeling tests. And the flow stress curves of the steel were obtained for various combinations of the temperature and strain rate. Based on the results of the tests, the complex forming process of a retaining ring including punching, expanding and extrusion with an enclosure was put forward and simulated by means of numerical simulation method. The results indicate that the process is a novel and force-saved practical technology for manufacturing heavy retaining rings.

镦挤复合变形力的理论解

尝试用上限法求解非稳态镦挤复合变形。通过剖分网格建立运动学许可速度场，实测的法兰盘镦粗半径R0带入求解；比较了理论值与实测值的误差，得到了吻合较好的上限解。

汽车双联主动齿轮的冷锻成型工艺

介绍了汽车变速箱中的一个关键零部件—双联主动齿轮的冷态镦粗、挤压及冲孔的复合成型工艺。该生产工艺自动化程度高、成型质量好,在很大程度上减少了锻后机加工的工作量,节约了大量的金属原材料及机加工成本。

基于Deform-3D的带齿轴套锻造工艺仿真与实践

某带齿轴套需经过缩径、镦粗、反挤压、冲孔等多级锻造实现成形,其工艺复杂、效率低、成本高,急需改进。提出了一种闭式锻造新工艺,采用组合式冲头结构实现了一次锻造成形。并利用有限元技术对改进后的工艺进行了全面分析,包括带齿轴套的成形经过、应力应变分析、载荷曲线变化、轴套锻后温度分布等。根据模拟结果可知,改进后的工艺简单可靠,得到的带齿轴套充填完整,不存在表面缺陷,内部流线连续均匀,质量较好。在同等条件下利用液压机进行了锻造试验,获得的产品与模拟效果一致,经质检,产品的齿形清晰完整,各处尺寸均能达到要求,表明改进后的工艺能起到提高生产效率和降低成本的作用,同时证实了有限元技术在工艺研究方面的指导作用。