长期高温高压氢暴露对Cr-Mo钢断裂韧性和裂纹行为的影响  

Effect of Long-term High Temperature and Pressure Hydrogen Exposure on Fracture and Fatigue Behaviors of Cr-Mo Steel

作　　者：李晓刚[1,2] 李明[1] 董超芳[1] 陈华[1] 李晓刚 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]中国科学院金属研究所金属腐蚀与防护国家重点试验室,沈阳110016

出　　处：《北京科技大学学报》2002年第4期418-421,共4页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(No.59971011);"973"资助项目(No.199900650)

摘　　要：选用Cr-Mo钢经400℃,20MPa,104h氢暴露后进行拉伸、断裂韧性和疲劳试验.结果表明:Cr-Mo钢已经发生了氢腐蚀,氢蚀使Cr-Mo钢强度、塑性和断裂韧性均有所降低,也使断裂机制由韧窝型转变为解理脆性.氢蚀使疲劳裂纹扩展行为也发生了变化,疲劳裂纹扩展速率增加,ΔKth降低.Cr-Mo钢氢蚀后,随应力比增加,疲劳裂纹扩展门槛值大幅度降低.Cr-Mo steel exposed to hydrogen gas at 400℃, 20MPa for 105 h were checked for making tensile test, fracture and fatigue test in order to investigate the effect of hydrogen attack on mechanical properties of Cr-Mo steel. The results showed that strength, ductility and fracture toughness were lowered caused by hydrogen attack for Cr-Mo steel. The fracture mechanism was changed from dimple fracture surface to embri-ttlement by hydrogen attack. The propagation rate of fatigue crack of Cr-Mo steel with hydrogen attack was increased caused by hydrogen attack, but threshold values decreased largely with increasing of stress ratio R. The fatigue mechanism was also changed from ductility to embrittlement by hydrogen attack.

关 键 词：高温高压氢暴露 断裂韧性 裂纹行为 CR-MO钢 氢蚀 疲劳裂纹 门槛值 断裂机制 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG172.3[金属学及工艺—金属材料]