腐蚀后M24高强度螺栓疲劳性能试验

Fatigue Test of M24 High Strength Bolt after Corrosion

为了探究高强度螺栓腐蚀后的疲劳性能,对浸油和无浸油的M24高强度螺栓开展了中性盐雾加速腐蚀试验,对不同腐蚀程度的高强度螺栓分别开展了形貌观察和常幅疲劳试验。结果表明:所有高强度螺栓表面锈层均由内锈层和外锈层组成;腐蚀后螺牙损失严重,并且螺牙根部也存在蚀坑;随着腐蚀时间的增加螺栓的疲劳寿命逐渐降低,浸油和无浸油螺栓腐蚀150 d之后疲劳寿命分别下降了36%和28%;由于浸油螺栓表面的保护层在腐蚀前期被破坏,相同腐蚀时间浸油和无浸油两种螺栓的疲劳寿命相差较小。

To explore the fatigue behavior of high-strength bolts after corrosion,neutral salt spray accelerated corrosion tests were carried out on M24 high-strength bolts with and without oil-immersed treatment.Successively,morphology observation and constant amplitude fatigue tests were carried out on M24 high-strength bolts with different corrosion time.The results show that the surface rust layer of all high-strength bolts is composed of inner rust layer and outer rust layer.After corrosion,pits were observed in the root of screw tooth.With the increase of corrosion time,the fatigue life of oil-immersed and oil-free bolts decreases by 36%and 28%respectively after 150 days of corrosion.Because the protective layer on the surface of oil-immersed bolt is damaged in the early stage of corrosion.The fatigue life shows little difference between oil-immersed bolt and oil-free bolt with same corrosion time.