海洋腐蚀环境下Q690高强钢对接焊缝连接的力学性能研究

Study on mechanical properties of Q690 high-strength steel butt weld joint in marine corrosive environment

为研究海洋环境腐蚀对高强钢对接焊缝力学性能的影响,对不同锈蚀程度下的高强钢对接焊缝连接进行了微观形貌扫描和静力拉伸试验,分析了试件表面形貌与腐蚀时间的变化规律,建立了屈服强度、极限强度、弹性模量等力学参数的退化关系,基于二次塑流模型给出了不同腐蚀程度下高强钢对接焊缝连接的本构模型。结果表明:随着腐蚀时间的增加,红褐色腐蚀产物逐渐增多,试件的屈服强度、极限强度和弹性模量逐渐减小,延性降低;在腐蚀100d后,蚀坑深度达到440μm,弹性模量相对降低7.8%,屈服强度降低了8.28%;二次塑流模型能准确模拟不同腐蚀程度下高强钢对接焊缝连接的应力-应变关系,具有良好适用性。

To study the effect of marine environmental corrosion on the mechanical properties of high-strength steel butt weld joint,the micro-morphological scanning and static tensile tests of high-strength steel butt weld joints under different degrees of corrosion were carried out.The variation law of surface morphology and corrosion time of the specimen was analyzed,and the degradation relationship of mechanical parameters such as yield strength,ultimate strength and elastic modulus were established.Based on the secondary plastic flow model,the constitutive model of high-strength steel butt weld joint under different corrosion degrees was given.The results show that with the increase of corrosion time,the reddish-brown corrosion products gradually increase,and the yield strength,ultimate strength and elastic modulus of the specimens decrease gradually,and the ductility decreases.After 100 days of corrosion,the pit depth reached 440μm,the elastic modulus decreased by 7.8%relatively,and the yield strength decreased by 8.28%.The secondary plastic flow model can accurately simulate the stress-strain relationship of high-strength steel butt weld joints under different corrosion degrees,and has good applicability.