2205双相不锈钢焊接结构疲劳裂纹扩展速率研究

Fatigue Crack Behavior of Welded Structure of Duplex Stainless Steel 2205

在不同应力比R下,采用标准SE(B)试样,在PLG-200高频试验机上对2205双相不锈钢的焊缝(WM)、热影响区(HAZ)和母材(BM)进行疲劳裂纹扩展速率试验,获得了2205双相不锈钢在各种应力比下的回归方程和扩展速率da/dN与应力强度因子ΔK的关系曲线。结果表明:2205双相不锈钢焊接结构中焊缝裂纹扩展速率最低,抗疲劳裂纹扩展能力最高;母材疲劳裂纹扩展速率最高,抗疲劳裂纹扩展能力最差;焊缝对应力变化的灵敏度最高,热影响区次之,母材最弱。

Take standard SE （B） as a sample, the fatigue crack growth behavior of weld metal （WM） , heat affected zone （HAZ） and base metal（BM） of Duplex Stainless Steel 2205 were tested on PLG-200 fatigue testing machine under different stress ratios. Through regression analysis of experimental data, the regression equation and the curve of the propagation rate da/dN and the stress intensity factor AK were obtained. The results show that the fatigue crack growth rate of WM is the slowest and the ability to resist fatigue crack growth is the highest in the three parts while BM is just the opposite. Secondly, as for the sensitivity to the stress change, WM is the highest, then HAZ, and BM is the lowest.