摘要
研究了30CrMnsiNi2A高强钢在恒幅载荷下的小裂纹起始特征和裂纹扩展特性试验结果表明，小裂纹起始于缺口表面初始缺陷（如夹杂或孔洞）处在应力比R＝0的恒幅载荷下，未显示小裂纹效应；在R＝－1的恒幅载荷下，则显示出小裂纹效应的存在利用裂纹闭合模型和微观结构缺陷作为初始裂纹尺寸的方法预测了小裂纹扩展速率和疲劳全寿命，预测值与实验值符合良好.
Single-edge-notched tension (SENT) specimens under constant load amplitude were used to obtain the small crack growth information via an acetate replica method. The observed results show that more cracks are surface ones and initiated at inclusion-particles or voids on the surface of the notch. Steel 30CrMnSiNi2A does not exhibit a significant short crack effect when stress ratio R=0. But a slight small crack effect was observed at R=-1, and the short cracks can grow below the long crack threshold. Using the closure crack growth model and a microstructural defect as an initial crack, the small crack growth rate and the total fatigue life can be predicted and the predicted results are in reasonable agreement with experiments.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第3期277-286,共10页
Acta Metallurgica Sinica
基金
国防科工委"八五"预研项目
关键词
裂纹
扩展速率
疲劳
寿命
预测
高强钢
small crack, crack growth rate,fatigue life prediction
