摘要
采用16Mn钢三点弯曲试样,研究了塑性冲击波和弹性冲击波作用区疲劳裂纹扩展速率da/dN的变化结果表明,经过爆炸处理,da/dN在整个冲击波作用区(约100mm)均有明显降低,以塑性冲击波作用区最为明显在整个纯弹性波作用区,如果△K相同,则爆炸处理后的da/dN在不同位置的弹性波作用区基本相同认为冲击波作用下材料具有的裂纹闭合效应使有效应力强度因子△K_(eff)的减小是da/dN下降的主要原因在塑性波冲击区,裂纹闭合主要由裂纹尖端产生的塑性形变和氧化物形成;
Changes of fatigue crack growth rate, dα/dN, at affecting region of eitherplastic or elastic shock wave have been studied with three-point bending specimens made oflow alloy steel 16Mn. The dα/dN at whole affecting regions by shock wave, about 100 mmdepth, is significantly reduced, especially at the plastic wave affecting region. Thedα/dN keeps basically constant at pure elastic wave affecting region under same ΔK. It isconsidered that the decrease of effective stress intensity factor ΔK_(eff) of the material with crackclosure effect is the main reason for reducing dα/dN after shock wave treatment. At plasticwave affecting region, crack closure occurs mainly through plastic deformations at crack tipand oxides; at elastic wave affecting region, through plastic deformations and roughness.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第6期A278-A282,共5页
Acta Metallurgica Sinica
基金
国家自然科学基金
