10CrNi3MoV钢低匹配对接接头的拉伸疲劳性能

Mechanical and fatigue properties of undermatching butt joints of 10CrNi3MoV steel

通过余高削平的10CrNi3MoV钢低匹配对接接头的拉伸和脉动拉伸疲劳试验,研究了匹配比对高强钢对接接头力学性能的影响,给出了匹配比与削平对接接头疲劳强度及寿命的关系方程.结果表明,随匹配比降低,削平对接接头抗拉强度、断后伸长率和疲劳强度降低,但匹配比对接头抗拉强度影响较小,对断后伸长率和疲劳强度影响较大;由于焊缝冶金强化和力学强化效应的作用,接头抗拉强度和疲劳强度远高于焊缝熔敷金属本身.匹配比过低的焊接结构缺少满足需要的塑性储备,以接头断裂模式为标准,进行了匹配比下限值的初步界定.

Based on the tension and pulse fatigue tests,the influence of mis-match ratio on mechanical performance of undermatching flush butt joints of 10CrNi3MoV steel was studied, and the empirical equations for the relationship between mis-match ratio and fatigue strength (or fatigue life) of joints were built. The results of experiments illustrated that the tensile strength, specific elongation and fatigue strength of flushing butt joints decreased with the decreasing mis-match ratio, and the influence on specific elongation and fatigue strength was obviously higher than that on the tensile strength. The tensile strength and fatigue strength of undermatching flush butt joints exceed their deposited metals by the metallurgic strengthening effect and constrained strength effect on weld metal. Because a low to excess of mis-match ratio welded structure lacking plasticity reserve of need, the preliminary definition of low limit of mis-match ratio was attempted under standard of the rupture models of welded joints.