摘要
分别对轧态、空冷和盐浴等温3种条件下U20Mn新型贝氏体重轨钢紧凑型拉伸试样的Ⅱ区疲劳裂纹（疲劳扩展稳定区）的扩展速率进行了测定,并用激光扫描共聚焦显微镜（LEXT）对其疲劳裂纹的扩展轨迹进行观察分析,研究不同组织类型对贝氏体钢疲劳裂纹扩展行为的影响。结果表明：疲劳裂纹在粒状贝氏体组织中的扩展偏折程度较为平缓,在条片状贝氏体组织中偏折严重,且随着条片的细化,其偏折程度也越大,所对应的Ⅱ区疲劳裂纹扩展速率也相应呈减缓趋势。
The fatigue crack propagation rates of fatigue zone（ fatigue propagation Ⅱ zone） of a new U20 Mn bainite heavy rail steel compaction test sample under three conditions（ rolling state,air-cooled state and 380 ℃ salt bath isothermal treatment） were measured.The fatigue crack propagation path was observed by laser scanning confocal microscopy（ LEXT）,and the effects of different microstructure on the fatigue crack propagation behavior of the bainitic steel were studied. The result shows that the deflection degree of the fatigue crack in granular bainite is relatively smooth,but in the lamellar bainite is serious. With the refinement of the strip,the degree of deflection is greater,and the fatigue crack propagation rate in the corresponding Ⅱ zone also decreases accordingly.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2018年第2期119-124,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51361021)
内蒙古自然科学基金(2017MS0511)
内蒙古自治区科技创新引导基金
关键词
钢轨
贝氏体组织
疲劳裂纹扩展速率
裂纹扩展路径
rail
bainite structure
fatigue crack propagation rate
crack propagation path
