局部锈蚀钢材的低周疲劳试验研究

Experimental Study on Low Cycle Fatigue of Local Corroded Steel

处于腐蚀性工作环境中的钢结构工程常出现局部钢材锈蚀,对其疲劳性能的影响显著。为研究局部锈蚀钢材低周疲劳寿命的退化规律,以Q235钢板为基础材料,考虑局部锈蚀坑深度和锈蚀坑纵向长度2个因素,制作4个光滑试件,并采用电化学加速锈蚀法制作24块试件,同时对这2种试件进行轴向拉伸低周疲劳试验。试验结果表明:锈蚀坑纵向长度和锈蚀坑深度均能使钢材低周疲劳寿命下降,锈蚀坑深度是主要因素;对锈蚀试件疲劳寿命影响较大的锈蚀坑深度为0.60~1.10 mm区间,超出此区间,试件疲劳寿命将在低水平保持稳定。

Local steel corrosion often occurs in steel structure engineering in corrosive working environment,which has obvious influence on fatigue performance. In order to study the degradation law of low cycle fatigue life of locally corroded steel, taking Q235 steel plate as the basic material, four smooth specimens are made,and 24 specimens are made by electrochemical accelerated corrosion method, considering two factors of local corrosion pit depth and longitudinal length of corrosion pit. At the same time, the axial tensile low cycle fatigue tests of the two specimens are carried out. The test results show that the longitudinal length and depth of corrosion pits can reduce the low cycle fatigue life of steel, and the depth of corrosion pits is the main factor;The corrosion pit depth which has a great influence on the fatigue life of corroded specimens is 0.60~1.10 mm.Beyond this range, the fatigue life of specimens will remain stable at a low level.