中南大学学报（自然科学版）2025，Vol.56Issue(6)：2228-2235,8.DOI:10.11817/j.issn.1672-7207.2025.06.008
应力比对高碳Q—P—T钢疲劳裂纹扩展行为的影响
Effect of stress ratio on fatigue crack propagation behavior of high carbon quenching-partitioning-tempering steel
摘要
Abstract
Fatigue crack growth tests and microstructure characterization of high carbon quenching-partitioning-tempering(Q-P-T)steel were carried out at three different stress ratios(R=—0.5,0,0.5),respectively.The results show that the crack propagation rate of high carbon Q-P-T steel increases with the increase of stress ratio R.The fatigue crack propagation is a mixture of transgranular fracture and intergranular fracture.With the increase of R,intergranular fracture in the crack stable expansion region gradually increases.When the effective stress intensity factor range ΔKeff is used to characterize the crack growth rate of the sample,the crack growth rate curves at different R almost overlap,indicating that the crack closure effect is the mechanism by which the stress ratio affects the crack growth rate.When R=-0.5,the geometrically necessary dislocation density near the crack is higher than that of the other two groups and is evenly distributed,indicating that more uniform plastic deformation occurs in the process of fatigue crack propagation,and the crack tip is easier to close,resulting in a decrease in the driving force of crack propagation,thus delaying the crack propagation.关键词
淬火—分配—回火(Q-P-T)工艺/应力比/裂纹扩展/裂纹闭合Key words
Q—P—T process/stress ratio/crack propagation/crack closure分类
矿业与冶金引用本文复制引用
宋子欣,秦盛伟,朱志民,刘冰阳..应力比对高碳Q—P—T钢疲劳裂纹扩展行为的影响[J].中南大学学报（自然科学版）,2025,56(6):2228-2235,8.基金项目
国家超级计算郑州中心创新生态系统建设科技专项(201400211200) （201400211200）
国家自然科学基金资助项目(52001281) （52001281）
河南省高等学校重点科研项目计划(25A430025)(Project(201400211200)supported by the Department of Science and Technology of Henan Province （25A430025）
Project(52001281)supported by the National Natural Science Foundation of China （52001281）
Project(25A430025)supported by the Education Department of Henan Province) （25A430025）
