• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2024, Vol. 60 ›› Issue (16): 118-129.doi: 10.3901/JME.2024.16.118

• 材料科学与工程 • 上一篇    下一篇

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新型马氏体耐热钢耦合控制下蠕变-疲劳循环变形研究

赵雷1,2, 张利宾1,2, 宋恺1,2, 徐连勇1,2, 韩永典1,2, 郝康达1,2   

  1. 1. 天津大学材料科学与工程学院 天津 300350;
    2. 天津市现代连接技术重点实验室 天津 300350
  • 收稿日期:2023-10-17 修回日期:2024-02-01 出版日期:2024-08-20 发布日期:2024-10-21
  • 作者简介:赵雷(通信作者),男,1985年出生,博士,副教授,博士研究生导师。主要研究方向为焊接结构及增材结构的疲劳、断裂、蠕变与损伤。E-mail:zhaolei85@tju.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(52075374)。

Research on Creep-fatigue Cyclic Deformation of New Martensitic Heat Resistant Steel

ZHAO Lei1,2, ZHANG Libin1,2, SONG Kai1,2, XU Lianyong1,2, HAN Yongdian1,2, HAO Kangda1,2   

  1. 1. School of Materials Science and Engineering, Tianjin University, Tianjin 300350;
    2. Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350
  • Received:2023-10-17 Revised:2024-02-01 Online:2024-08-20 Published:2024-10-21

摘要: 蠕变疲劳相互作用(Creep fatigue interaction,CFI)是制约电力和航空等领域高温部件可靠运行的主要因素。采用应变控制(Conventional strain-controlled creep fatigue interaction,CCFI)和应力-应变混合控制(Hybrid stress-strain controlled creep fatigue interaction,HCFI)两种耦合控制模式研究新型马氏体耐热钢的蠕变-疲劳性能,对比两种模式下的蠕变损伤累积规律和微观损伤机制,分析总应变范围、保载时间和保载应力对新型马氏体耐热钢蠕变-疲劳性能的影响。结果表明,CCFI和HCFI的断裂寿命随总应变范围增大而降低。此外,增大保载应力以及保载时间会降低HCFI寿命。当HCFI中保载应力或保载时间增加时,单个循环所累计的蠕变损伤会显著增加,这说明HCFI试验更适合表征蠕变损伤主导的CFI。针对两种控制模式下的蠕变-疲劳寿命预测,讨论寿命分数法(Time fraction,TF)、延性耗散法(Ductility exhaustion,DE)以及修正的应变能密度耗散法(Modified strain energy density exhaustion,MSEDE)的预测精度。结果表明,修正的应变能密度耗散法由于考虑平均应力对蠕变-疲劳的影响,可以更好地表征蠕变疲劳中的蠕变损伤。对于HCFI采用了平均蠕变速率对DE和MSEDE模型进行修正,使得其预测的平均相对误差降低了一半。

关键词: 蠕变-疲劳, 应力-应变混合控制, 寿命预测, 损伤演化

Abstract: Creep fatigue interaction(CFI) is the primary factor which restricts the safe operation of high-temperature components in many fields. Two modes, conventional strain-controlled creep fatigue interaction(CCFI) and hybrid stress-strain controlled creep fatigue interaction(HCFI) are adopted to study the creep-fatigue properties of G115 martensitic heat resistant steel. In addition, the accumulation of creep damage and microstructural evolutions under these two modes are compared. The effects of total strain range, load holding time, and load holding stress on creep-fatigue properties of G115 steel are emphatically analyzed. The results show that the rupture lives of CCFI and HCFI are reduced as the total strain range increased. Moreover, the rupture life of HCFI is reduced with the increasing hold stress and hold time. The accumulated creep strain in one cycle increased when the hold stress or the hold time increased in HCFI. This indicated that HCFI test is more suitable for characterizing creep-dominated CFI. For creep-fatigue life prediction under two modes, the predictive accuracy of time-fraction(TF) method, ductility-exhaustion(DE) method and modified strain energy density exhaustion(MSEDE) method are discussed. The results show that the MSEDE method can better describe creep damage in creep-fatigue considering the effect of average stress on creep fatigue. For HCFI, the average creep rate is used to modify DE and MSEDE models, which reduces the mean relative error of prediction by half.

Key words: creep-fatigue, hybrid stress-strain controlled, life prediction, damage evolution

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