摘要
采用阶梯能量示波冲击试验法研究了铸造双相不锈钢冲击弯曲破断时,裂纹的萌芽、生长、扩展3个阶段与载荷-位移曲线及断口的对应关系,研究了裂纹的生长与扩展速率。结果表明,裂纹萌芽于屈服后的第2个载荷-位移曲线高峰。裂纹生长的临界尺寸对应于载荷-位移曲线平台后的第2个下跌槛。裂纹生长对应于断口上的启裂区。裂纹扩展对应于断口上的扩展区。在启裂前区裂纹以较低速率波动生长,启裂后区裂纹的生长速率更趋减缓。裂纹扩展的前期扩展速率很高,后期则迅速下降。裂纹从萌芽到生长至临界尺寸耗费了总破断功的76.2%。
The relationship between the three steps of crack initiation, growth and propagation and the curve of load-distance and fracture was studied for the as-cast duplex stainless steel through step sharp impact test, and crack growth and propagation rate were obtained. The results show the crack is initiated after the 2nd high peak of load-displacement curve. The critical size, crack growth and propagation correspond with the 2nd slump after the curve terrace the initiation of fracture, and the spread of fracture respectively. The cracks grow in a low fluctuating rate before initiation; the growth rate of crack is much lower after initiation. The propagation rate is higher during the early propagation, but it decreases rapidly in the later. Approximate 76.2% of total fracture works is consumed from the initiation to the critical size.
出处
《铸造技术》
CAS
北大核心
2007年第8期1059-1062,共4页
Foundry Technology
关键词
CSS
启裂区
扩展区
生长速率
扩展速率
CSS （cast stainless steel）
Crack initiation
Crack propagation
Growth rate
Propagation rate
