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研究了经高温高压渗氢后 ,30 9L 和 347L 不锈钢堆焊层短裂纹的低频疲劳特性。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 ,经热渗氢后 ,30 9L和 347L堆焊层裂纹扩展的门槛值 (ΔJth)分别从空气中的 196× 10 - 6 MN/m和 35 5× 10 - 6 MN/m,下降为 144× 10 - 6 MN/m和 2 5 2× 10 - 6 MN/m;da/d N～ ΔJ曲线也比空气中的向左移 ,提高了裂纹扩展速度。说明热渗氢显著增加了不锈钢堆焊层低频破坏的敏感性
The low-frequency fatigue characteristics of short cracks in 30 9L and 347L stainless steel overlays after high temperature and high pressure hydrogenation were studied. The crack propagation velocity and threshold were calculated using da / d N = C (ΔJ) n. The results show that the threshold value of crack growth (ΔJth) of 30 9L and 347L overlay layers decreases from 196 × 10-6 MN / m and 35 5 × 10-6 MN / m in air to 144 × 10 - 6 MN / m and 2 5 2 × 10 - 6 MN / m, respectively. The da / d N ~ ΔJ curve is also shifted to the left of the air, increasing the crack growth rate. It shows that the thermal hydrogen permeability significantly increases the sensitivity of low frequency destruction of stainless steel overlay