摘要
金属材料焊接接头的腐蚀疲劳失效往往会引发严重的工程事故。本工作对G20Mn5QT/Q355异种钢对接焊接接头在模拟海水环境下的腐蚀疲劳性能进行了研究,开展了其在3.5%NaCl溶液中的腐蚀疲劳试验,并对腐蚀疲劳断口进行了扫描电子显微镜试验,分析了其腐蚀疲劳的失效机理。揭示了在较大应力水平(>220 MPa)下,母材缺陷及焊接缺陷是导致裂纹形核的主要原因;而在较小应力水平(≤220 MPa)下,表面蚀坑是导致裂纹形核的主要原因。分别采用Stromeyer公式与基于三参数威布尔分布的模型建立了对接焊接接头的腐蚀疲劳寿命预测方法,结果表明三参数威布尔分布的腐蚀疲劳S-N曲线拟合精度更高,对实际工程疲劳设计具有指导意义。
Corrosion fatigue failure of welded joints of metal materials often leads to serious engineering accidents.In this work,the corrosion fatigue behavior of butt-welded joints of G20Mn5QT/Q355D dissimilar steel is studied,and the corrosion fatigue test in 3.5wt%NaCl solution is carried out.The corrosion fatigue fracture is observed by scanning electron microscope(SEM),and the failure mechanism of corrosion fatigue is analyzed.It is revealed that the defects(casting defects and welding defects)are the main causes of crack nucleation under the larger stress level(≥220 MPa).However,under the smaller stress level(≤220 MPa),the corrosion pit on the surface is the main cause of crack nucleation.The corrosion fatigue S-N curves of butt welded joints are established by Stromeyer expression and three-parameter Weibull distribution,respectively.The results show that the corrosion fatigue S-N curve with three-parameter Weibull distribution is more applicable in the prediction of corrosion fatigue life.
作者
芦燕
余振超
王如琦
LU Yan;YU Zhenchao;WANG Ruqi(Key Laboratory of Coast Civil Structure Safety of China Ministry of Education,Tianjin University,Tianjin 300350,China;School of Civil Engineering,Tianjin University,Tianjin 300350,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第19期170-176,共7页
Materials Reports
基金
国家自然科学基金(52278199,52022067)
天津市科技计划项目(23ZYYYJC00010)。
