基于微粒子喷丸处理的螺栓防松能力改善研究

目的基于试验测试结果,研究微粒子喷丸(FPP)技术对螺栓防松性能的影响及机理。方法使用微粒子喷丸工艺处理了两种硬度不同的螺栓(不锈钢螺栓和镀锌螺栓),使用螺栓横向振动试验装置在液压伺服万能疲劳试验机上对以上两种类型的未喷丸螺栓及喷丸螺栓进行了反复加载振动试验。试验结束后,使用扫描电镜(SEM)对螺纹配合处的螺栓螺牙进行了磨损形貌观察。结果未喷丸情况下,镀锌螺栓比不锈钢螺栓的防松能力低约40%。微粒子喷丸处理后,镀锌螺栓的防松能力提高了28%,而不锈钢螺栓的防松能力提高了15%,微粒子喷丸对镀锌螺栓的防松能力提高更加显著。螺纹表面的磨损程度越低,螺栓的防松能力越强。结论微粒子喷丸处理提高了螺牙表面的硬度,减轻了螺牙的磨损程度,从而改善了螺栓的防松性能。微粒子喷丸技术对螺栓防松能力的改善程度随着螺栓螺牙表面硬度的增加而增大。

Improvement of Anti-loosening Performance of Bolts Treated by Fine Particle Peening

The work aims to effects of fine particle peening (FPP) technology on anti-loosening performance of bolts based on experimental test results. Two types of bolts of different hardness (stainless steel bolts and galvanized bolts) were treated by applying FPP technology. Then, repeatedly vibration tests were performed to the aforesaid original and shot-peened bolts with a transverse vibration testing apparatus on a hydraulic servo fatigue tester. Wear morphology of bolt threads where screw-thread fit occurred with a SEM after the tests. The anti-loosening performance of galvanized bolts was 40% lower than that of stainless steel bolts. After the galvanized bolts and stainless steel bolts were treated by particle shot blasting, the anti-loosening performance of the two types of bolts increased by 28% and 15%, respectively. The anti-loosening performance of galvanized bolts improved more remarkably after particle shot blasting. The lower the wear degree was, the better the anti-loosening performance would be. Particle shot blasting treatment can improve hardness of thread surface, wear degree of thread and improve anti-loosening performance of bolts. Improvement effect of particle shot blasting technology on the anti-loosening performance of bolts increases as surface hardness of bolt threads increases.