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研究采用J积分方法研究了GH690合金在饱和氢水浴条件下不同载荷速率的断裂韧性,探讨了载荷速率对断裂行为的影响机制。研究发现,当载荷速率低于0.07 mm/min时,饱和氢水中GH690合金的断裂韧性随载荷速率的降低而下降。低载荷速率下,水浴中的氢以Cottrell氢气团的形式随位错迁移到裂纹尖端,并在晶界碳化物处富集,降低晶界碳化物与基体界面之间的结合强度,导致合金的断裂韧性降低。
The J integral method was used to study the fracture toughness of GH690 alloy at different loading rates in a saturated hydrogen water bath and the mechanism of the effect of loading rate on the fracture behavior was discussed. The results show that the fracture toughness of GH690 alloy in saturated hydrogen water decreases with the decrease of loading rate when the loading rate is lower than 0.07 mm / min. At low loading rates, hydrogen in the water bath migrates to the crack tip with dislocations in the Cottrell hydrogen mass and enriches at the grain boundary carbides, reducing the bond strength between the grain boundary carbides and the matrix interface, causing the Fracture toughness decreased.