摘要
针对大型工程机械用800 MPa低合金高强度钢及其焊接接头,进行低周疲劳性能研究。试验在常温下进行,对称三角波加载。试验结果表明,母材两个轧制方向的应变疲劳寿命没有明显差别,焊接接头的疲劳寿命偏低。焊接接头的局部软化是应变集中,导致应变疲劳寿命降低的主要原因。应变疲劳断口有明显的条纹特征,母材疲劳断口上伴有与条纹平行的二次裂纹,焊接接头的疲劳断口条纹清晰且宽度较细。试验确定的循环应力应变特性参数和应变疲劳寿命参数有明显的相关关系。
Low cycle fatigue performance of 800 MPa grade high strength low alloy steel and its welded joint for construction machinery was studied.The test was conducted under triangular wave loading and ambient temperature.It is indicated that the fatigue life has no obvious difference between two rolling directions,and the fatigue life of welded joint is lower than that of base metal.The main reason of the decrease in the strain fatigue life is the local softness and then the local strain concentration of welded joints.There exists clear fatigue striation feature.There are secondary cracks parallel to the fatigue striations on the fractograph of base metal.The striations are clear and the width of striation is narrow on the fractograph of welds.Moreover,there is obvious correlation between the cycle stress-strain characteristic parameters and the strain fatigue life parameters.
出处
《兵器材料科学与工程》
CAS
CSCD
2011年第1期24-27,共4页
Ordnance Material Science and Engineering
关键词
低合金高强度钢
焊接接头
低周疲劳
high strength low alloy steel
welded joint
low cycle fatigue
