整体式挂车支承桥主轴变温挤压成形工艺

Extrusion forming process with variable temperature for integral main shaft of trailer support bridge

根据13 t整体式挂车支承桥主轴产品的结构特点,提出了无缝钢管挤压缩径成形新工艺。通过精确控制温度场梯度,提高无缝钢管变形区的支撑能力,实现端部缩径系数大幅降低。采用数值模拟结合工艺试验的方法,揭示了主轴成形过程中金属的流动状态以及关键工艺参数对产品成形性和壁厚分布的影响规律。结合主轴的形状尺寸要求和变温成形的工艺性,对工艺参数的取值或选择范围进行了优化。在双向挤压液压机上进行了工艺试验并得到了形状尺寸合格的样件,各工序变形区的壁厚分实测数值与数值模拟基本吻合,验证了数值模拟的正确性和工艺的可行性。与传统工艺相比,新工艺实现了挂车主轴少火次、短工艺流程的精密快捷成形。

According to the structure characteristics of the main shaft of a type of 13 t integral trailer support bridge,the neck-extruding technology for manufacturing the main shaft with a seamless steel tube was put forward. Then,the support capacity of the deformation zone of seamless steel tube was improved by controlling the temperature gradient precisely,and the coefficient of necking at the end was greatly reduced. Through the numerical simulation and practical experiment,the influences of metal flow status and key process parameters on the formability and wall thickness distribution of the metal during the forming process were obtained,and the value or range of the corresponding process parameters were optimized by combining with the shape-size of the main shaft and the manufacturability of extrusion with variable temperature. Furthermore,the practical experiments were conducted on a bidirectional extrusion hydraulic press,and the samples with qualified shape and size were obtained. In addition,the wall thickness distribution in deformation zone in each process basically agreed with that of the numerical simulation,which indicates that the numerical simulation was reasonable and the forming process was feasible.Compared with the traditional process,the new technology realized the precision and quick forming of the main shaft with less heating passes and technical processes.