摘要
研究了在600~20℃热疲劳试验条件下,铸态蠕墨铸铁热疲劳裂纹萌生和扩展行为。结果表明：基体组织的强度、热稳定性以及石墨形态能影响热疲劳裂纹的萌生和扩展。主裂纹的扩展是从人工缺口出发,避开珠光体区域,穿过铁素体区域。裂纹沿着蠕虫状石墨与基体组织的边界或铁素体-珠光体晶界前进。随着热疲劳次数的增加,珠光体中的渗碳体分解,强度下降,裂纹扩展速度加快。
The thermal fatigue crack initiation and propagation behavior of as-cast vermicular graphite cast iron under thermal cycle conditions of 600-20℃ was investigated. The results show that the initiation and propagation of thermal fatigue crack are affected by the strength and thermal stability of the microstructure and the morphology of graphite. The propagation of the major crack begins from the artificial gap, which can avoid the pearlite region, and pass the ferrite region. The crack increases along the outline between vermicular graphite and matrix or the grain boundary of ferrite-pearlite. With the thermal fatigue number increasing, the cementite in the pearlite is decomposed, the strength drops, and the crack propagation speed is accelerated.
作者
陈丹
吴素珍
陈海军
冀佳彬
CHEN Dan;WU Suzhen;CHEN Haijun;JI Jiabin(Department of Mechanical Engineering,Henan University of Engineering,Zhengzhou 451191,China)
出处
《热加工工艺》
CSCD
北大核心
2018年第16期61-64,共4页
Hot Working Technology
基金
河南省科技发展计划项目(162102210285)
关键词
蠕墨铸铁
热疲劳裂纹
萌生
扩展
vermicular graphite cast iron
thermal fatigue crack
initiation
propagation
