温度对动车组车轮钢服役次生疲劳裂纹起裂扩展特性影响

摘要/Abstract

摘要： 高速动车组车轮材料在严酷服役温度条件下的抗疲劳裂纹起裂与扩展能力是制定车轮合理维修周期和进行服役寿命评估的基础。选用高速动车组用ER8C车轮钢作为研究对象，对其在-60~60 ℃服役温度范围内进行了应力疲劳试验及疲劳失效机制探讨。结果表明：随着测试温度的升高，轮辋、轮辐材料疲劳寿命均呈现出显著缩短趋势；在较高的服役温度条件下，试样出现了半椭圆形的次生疲劳裂纹起裂扩展形貌特征，且由于轮辋与轮辐不同位置材料强度韧性的差异，使得产生次生疲劳裂纹起裂扩展形貌特征所对应的温度条件不同，对于轮辋材料，当试验温度升高到50 ℃时，试样开始产生次生疲劳裂纹，而对于轮辐材料，当试验温度升高到30 ℃时，试样便开始产生次生疲劳裂纹；通过对主次生疲劳裂纹的扩展特性比较分析可知，随着应力强度因子幅值的增大，材料微观薄弱区域由珠光体片层层间转变为珠光体团晶粒边界。

关键词: 车轮钢, 疲劳裂纹扩展, 次生裂纹, 服役温度

Abstract: School of Mechanical Engineering,Southwest Jiaotong University,Chengdu，610031
For high-speed railway wheel steels under severe service temperature conditions, fatigue crack initiation and growth behavior are important for planning maintenance interval and assessing residual lifetime. Fatigue tests were conducted under -60~60 ℃ test conditions for ER8C high-speed railway wheel steels and fracture morphologies were observed. The results show that the fatigue lifetime decreases as the temperature increases for both of wheel rim and web steels. Secondary fatigue crack initiation and growth area with shape of half ellipse exists under high testing temperature conditions. Furthermore, for wheel rim and web, the generation temperatures of secondary fatigue crack initiation and growth areas are different due to the diversity of steel strength and toughness, for wheel rim，this critical temperature is 50 ℃ while it is 30 ℃ for wheel web. Based on the comparison of growth characteristics between the main and secondary cracks, it may be concluded that the weak area changes from pearlite lamella to grain boundary of pearlite colony as the stress intensity factor range increases.

Key words: railway wheel steel； fatigue crack growth； secondary fatigue crack, service temperature

中图分类号:

U270.4

方修洋;黄伟;王俊国. 温度对动车组车轮钢服役次生疲劳裂纹起裂扩展特性影响[J]. 中国机械工程.

FANG Xiuyang;HUANG Wei;WANG Junguo. Effects of Temperature on Secondary Fatigue Crack Initiation and Growth Behavior of High-speed Railway Wheel Steels[J]. China Mechanical Engineering.

参考文献

[1]马蕾, 王文健, 郭俊, 等. 低温下高速车轮材料滚动磨损与疲劳损伤行为[J]. 机械工程学报, 2017, 53(20)：113-120.

MA Lei, WANG Wenjian, GUO Jun, et al. Rolling Wear and Fatigue Damage Behavior of High-speed Wheel Materials at Low Temperature[J]. Journal of Mechanical Engineering, 2017, 53(20)：113-120.

[2]杨柳青, 胡明, 赵德明, 等. CRH5动车组车轮低温概率疲劳寿命研究[J]. 中国机械工程, 2018, 29(9)：1115-1119.

YANG Liuqing, HU Ming, ZHAO Deming, et al. Research on Probabilistic Fatigue Lifes of CRH5 EMU Wheels at Low Temperature[J]. China Mechanical Engineering, 2018, 29(9)：1115-1119.

[3]张玉玲, 潘际炎. 低温对钢材及其构件性能影响研究综述[J]. 中国铁道科学, 2003, 24(2)：89-96.

ZHANG Yuling, PAN Jiyan. Study on Performance of Steel and the Components under Low Temperature[J]. China Railway Science, 2003, 24(2)：89-96.

[4]ZHU Z Y,LI G D, DAI G Z, et al. Mechanisms and New Parameter Attribute Reduction of High-speed Railway Wheel Rim Steel Subjected to Low Temperature Fatigue[J]. Materials Science & Engineering A, 2016, 673：476-491.

[5]WALTERS C L, ALVARO A, MALJAARS J. The Effect of Low Temperatures on the Fatigue Crack Growth of S460 Structural Steel[J]. International Journal of Fatigue, 2016, 82：110-118.

[6]张青松, 朱振宇, 高杰维, 等. 各向异性和偏轴加载对1050车轮钢疲劳性能的影响[J].金属学报, 2017, 53(3)：307-315.

ZHANG Qingsong, ZHU Zhenyu, GAO Jiewei, et al. Effect of Anisotropy and Off-axis Loading on Fatigue Property of 1050 Wheel Steel[J]. Acta Metallurgica Sinica, 2017, 53(3)：307-315.

[7]NIKAS D, AHLSTROM J, MALAKIZADI A. Mechanical Properties and Fatigue Behaviour of Railway Wheels Teels as Influenced by Mechanical and Thermal Loadings[J]. Wear, 2016, 366/367：407-415.

[8]AHLSTROM J, KARLSSON B. Modified Railway Wheel Steel: Production and Evaluation of Mechanical Properties with Emphasis on Low-cycle Fatigue Behavior[J]. Metallurgical and Materials Transaction A, 2009, 40(7)：1557-1667.

[9]宋志坤, 谢基龙, 张励忠, 等. 铁道货车车轮CL60钢在450 ℃时的低循环疲劳行为[J]. 北京交通大学学报, 2012, 36(4)：131-134.

SONG Zhikun, XIE Jilong, ZHANG Lizhong, et al. Low Cycle Fatigue Behaviours at 450 ℃ of CL60 Steel for Railway Freight Wheel[J]. Journal of Beijing Jiaotong University, 2012, 36(4)：131-134.

[10]杨冰, 赵永翔. 两种终加工工艺下LZ50车轴钢疲劳短裂纹扩展行为对比研究[J]. 铁道学报, 2013, 35(5)：34-39.

YANG Bing, ZHAO Yongxiang. Comparative Study on Short Fatigue Crack Growth Behavior of Axle Steel LZ50 with Two Final Processing Methods[J]. Journal of the China Railway Society, 2013, 35(5)：34-39.

[11]RAY K K, NARASAIAH N, SIVAKUMAR R. Studies on Short Fatigue Crack Growth Behavior of a Plain Carbon Steel Using a New Specimen Configuration[J]. Materials Science and Engineering A, 2004, 372：81-90.

[12]AKHMAD A, KORDA Y, MUTOH Y, et al. In Situ Observation of Fatigue Crack Retardation in Banded Ferrite-pearlite Microstructure due to Crack Branching[J]. Scripta Materialia, 2006, 54：1835-1840.

[13]LU W G, WANG Z, ZHAO J. Life Prediction by Ferrite-pearlite Microstructural Simulation of Short Fatigue Cracks at High Temperature[J]. International Journal of Fatigue, 2015, 80：349-356.

[14]MOHAMMAD S M, YOSHIHARU M. Effects of Size and Spacing of Uniformly Distributed Pearlite Particles on Fatigue Crack Growth Behavior of Ferrite-pearlite Steels[J]. Materials Science and Engineering A, 2010, 527：2592-2597.