超高强度钢MJ螺纹滚压强化工艺研究

The Process Research for MJ Thread Rolling Strengthening of Ultrahigh-strength Steel

采用专用滚轮对超高强度钢MJ螺纹牙底进行滚压强化，用SEM观察滚压前、后螺纹牙底的形貌变化，并测量滚压强化后的塑性变形量，用MTS疲劳试验机进行疲劳试验。结果表明，滚压强化后，MJ螺纹牙底有明显的光亮滚压带，完全覆盖了机械加工表面的车刀痕，表面形貌更光滑。经测量，滚压强化后，螺纹小径发生了0．005-0．015mm的塑性变形；与未滚压强化试样对比，滚压强化试样的疲劳寿命得到了显著提高。

Perform rolling strengthening for MJ thread root of ultrahigh strength steel with special roller, observe shape variation of thread root with SEM prior and post rolling, measure plastic deformation value post rolling strengthening and perform fatigue test with MTS fatigue testing machine. Results indicate that there is clearly bright roller band at MJ thread root post rolling strengthening, and completely cover turning tool mark of machining surface so that surface shape is more smooth. Small diameter of thread causes plastic deformation of 0. 005-0. 015 mm by measuring post rolling strengthening. Compared with not rolling strengthening samples, fatigue life of roiling strengthened samples is clearly improved.