16MnR钢焊接接头疲劳裂纹扩展行为及裂纹闭合效应的研究

Study on Fatigue Crack Spread Behavior and Closing Effects of 16MnR Steel Welding Joints

测定了16MnR母材、焊缝以及热影响区三种试件的疲劳裂纹扩展速率和在四个应力比(R=0.1,0.3,0.5,0.8)下的门槛值。得到了在疲劳裂纹扩展中速区和低速区的扩展规律。此外,还研究了残余应力和应力比对该钢种疲劳门槛值的影响,以及近门槛值域内疲劳裂纹的闭合效应。

Determines the fatigue crack spread rote of the 16MnR base metal、weld metal and heat affect zone, and the crack spread rules under constant-amplitude is gained. The threshold stress intensities and the fatigue crack spread rates near threshold under four stress ratios (R=0.1、0.3、0.5、0.8)are measured two. In addition, the effect of stress ratio and residual stress on the threshold value is researched, and the fatigue crack spread mechanism and crack closure behaviour near the threshold value is discussed.