孔边R型面挤压强化工艺技术研究

The Research on the Expansion Process for Hole's Edge R

针对小孔挤压、喷丸工艺无法有效提高零件孔边R型面的疲劳强度问题,研究提出了一种新型孔边R型面挤压强化工艺技术,设计了一套有效的挤压工艺装备。通过工艺试验验证表明,挤压后的孔边R型面与孔边、孔壁的过渡更圆滑,显著降低了R型面的表面粗糙度,大幅提高了其表面残余压应力水平,增大了残余压应力层厚度,使孔结构的疲劳寿命提高了40倍。

While the hole expansion process and shot peening process can＇t improve the fatigue strength of the hole＇s R surface effectively, a new hole＇s edge R expansion process is developed. By process tests with the new expansion equip- ments, the results show the new process could make the surface of the hole structure more smooth, improve the surface roughness of the hole＇s edge R significantly, the level of residual compressive stress on the surface could been improved greatly, and the thickness of the residual compressive stress layer could been increased. The fatigue life of the hole structure could been increased by 40 times.