腐蚀后M24高强度螺栓疲劳性能试验

为了探究高强度螺栓腐蚀后的疲劳性能,本文对浸油和无浸油的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；腐蚀后螺牙根部存在着蚀坑,浸油和无浸油螺栓腐蚀150天后螺牙根部的蚀坑直径达到1.5mm；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天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。

Experimental study on fatigue behavior of corroded M24 high strength bolt

To explore the fatigue behavior of high-strength bolts after corrosion, neutral salt spray accelerated corrosion tests are carried out on M24 high-strength bolts with and without oil-immersed treatment. Successively, morphology observation and constant amplitude fatigue tests are carried out on M24 high-strength bolts with different corrosion times. The results show that the surface rust layer of all high-strength bolts is composed of inner rust layer and outer rust layer. There were pits in the root of screw tooth after corrosion, and the diameter of pits in the root of screw tooth reached 1.5mm after 150 days of corrosion by oil-immersed and oil-free bolts. 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 destroyed in the early stage of corrosion, the fatigue life of oil-immersed bolt and oil-free bolt has little difference in the same corrosion time.