加载路径对不锈钢球形件内高压成形过程影响

Influence of loading paths on hydroforming process of stainless steel spherical part

为了研究加载路径对不锈钢球形件内高压成形过程的影响,采用实验方法分析了加载路径对成形过程中缺陷形式的影响,获得了80%膨胀率成形管件的壁厚分布规律.结果表明:当初始内压与屈服强度比值小于0.21时,管坯形成两个皱纹,在整形阶段发生开裂;当初始内压与屈服强度比值大于0.25时,管坯在轴向进给阶段即发生开裂.在初始内压与屈服强度比值为0.21～0.25时,可以成形出合格管件,合格管件最大减薄点位于球形件的最大截面处,最大减薄率为24.5%.本文所成形不锈钢球形件内高压成形区间,合理初始内压与屈服强度比值范围为0.21～0.25.

The influence of loading paths on hydroforming process of a stainless steel spherical part and the defects pattern was analyzed by experiment. And then thickness distribution of the formed part with the biggest expansion ratio up to 80% was gotten. It is shown that two wrinkles appear when the ratio of the initial pressure to the yield strength is smaller than 0. 21 and bursting occurs during the calibration. However, bursting occurs during axial feeding when the ratio of the initial pressure to the yield strength is bigger than 0. 25. The part can be formed successfully with the ratio of the initial pressure to the yield strength selected in the range from 0. 21 to 0. 25. The biggest thinning appears in the top of the sphere and the biggest thinning rate is 24.5%. A hydroforming process window of the stainless steel spherical part is established, and in this process window the reasonable ratio of the initial pressure to the yield strength is in the range from 0.21 to 0. 25.