摘要
应用弹塑性断裂力学和ΔJ参数 ,研究了原始状态与热渗氢后 3 4 7L不锈钢堆焊层短裂纹的疲劳破坏特性。并用 da/d N=C(ΔJ) n 计算了裂纹扩展速度和门槛值。结果表明 ,在氢的作用下 ,3 4 7L钢堆焊层裂纹扩展的门槛值 (ΔJth) ,从 3 55× 1 0 - 6 MN/m,下降为热渗氢后的 2 52× 1 0 - 6MN/m,da/d N～ΔJ曲线也比原始状态的向左移 ,提高了裂纹扩展速度。断口分析表明 ,氢既有在柱状晶界及滑移面上位错塞积处聚集 ,促进脆化的作用 。
The investingation on low frequency fatigue with short crack of the weld overlay cladding of 347L steel in original and hydrogen charged conditions indicated that the d a /dN~Δ J relation consisted of three stages relating to three equations with the model of d a /dN=C(Δ J ) n, respectively, on which the calculation of threshold value Δ J th ≈355×10 -6 MN/m for original and Δ J th ≈252×10 -6 MN/m for themal Hydrogen charged was based. The results showed that hydrogen increased obviously the propagation rate of the fatigue crack. In addition, the different crack propagation mechanism had been observed in three propagation stages after fracture analysis by SEM.
出处
《机械工程材料》
CAS
CSCD
北大核心
2000年第3期18-20,共3页
Materials For Mechanical Engineering
基金
浙江省自然科学基金资助项目! ( 5 980 2 3 )
