摘要
采用直流电位法,对国内试制的某超超临界汽轮机高中压转子用1Cr10Mo1W1NiVNbN钢在600℃下的蠕变裂纹、蠕变-疲劳裂纹萌生与扩展行为进行了研究,得到了该钢在不同初始应力强度因子条件下的蠕变裂纹扩展孕育时间关系式和蠕变裂纹扩展速率关系式.研究了不同保持时间对蠕变-疲劳裂纹扩展行为的影响,同时还分析了在不同条件下裂纹扩展行为与时间和循环的相关性.结果表明:疲劳缩短了蠕变-疲劳裂纹的扩展孕育期,加快了裂纹的扩展速度;在载荷保持时间较短的情况下,蠕变-疲劳裂纹扩展行为与循环相关;而在载荷保持时间较长的情况下,裂纹扩展行为与时间相关.
Initiation and growth behavior of creep and creep-fatigue cracks in the 1Cr10Mo1W1NiVNbN steel newly developed for ultra supercritical（USC） high/medium-pressure steam turbine rotors were investigated using DC current method at 600 ℃,during which 2 formulae were obtained for calculation of creep crack initiation time and growth rate under conditions of different initial stress intensity factors.Influence of hold time on creep crack growth behavior was studied while correlation between the growth behavior and time/cycle frequency analyzed.Results show that fatigue action may reduce the initiation time of creep-fatigue cracks and accelerate the crack growth rate.Creep-fatigue crack growth behavior is cycle-dependent under short hold-time conditions,but becomes time-dependent under long hold-time conditions.
出处
《动力工程学报》
CAS
CSCD
北大核心
2010年第4期304-308,共5页
Journal of Chinese Society of Power Engineering
基金
上海市科委重大科技攻关资助项目(08dz11003)
