针对水泥挤压辊的压缩疲劳工况，采用自行设计的双切口疲劳试样，试验了45钢母材上堆焊六种Fe-C-Cr-Nb合金的压缩疲劳行为. 对疲劳试样表面进行原位观察和激光共聚焦裂纹分析，切口的应力应变集中促进其下方热影响区（HAZ）局部滑移线聚集并形成塑性变形区，同时在切口底部边缘萌生疲劳裂纹，穿过堆焊合金扩展进入HAZ. 疲劳裂纹还在熔合线萌生并扩展，最后导致疲劳失效. 试验结果表明，疲劳试样的a-N曲线近似为直线. 堆焊合金基体组织主要为高硬度马氏体时，疲劳裂纹扩展速率大，疲劳寿命仅5万次；基体组织为较软的铁素体或奥氏体时，裂纹扩展速率小，疲劳寿命长达54万次.
The compression fatigue behavior of six kinds of Fe-C-Cr-Nb surfacing alloys on the base metal of 45 steel was tested with self-designed dual-notch fatigue specimens according to the compression fatigue working condition of the cement squeeze roller. In-situ observation and laser confocal crack analyses were carried out on the surface of fatigue specimens. The stress-strain concentration of the notches accelerated the accumulation of slip lines at local HAZ just below the notches and plastic deformation zones formed there. At the same time, fatigue cracks were initiated at the bottom edge of the notches and propagated into HAZ through surfacing alloys. Fatigue cracks were initiated and propagated along the fusion line as well and eventually resulted in fatigue failure. The experimental results show that the a-N curves of fatigue specimens were approximately straight lines. When the matrix micro-structures of the surfacing alloys were mainly composed of martensite with high hardness, the fatigue crack propagation rate is big and the fatigue life is only 50,000 times. While the micro-structures were composed of soft ferrite or austenite, the propagation rate is small and the fatigue life is up to 540,000 times.
[1] 钟群鹏.材料失效诊断、预测和预防[M].长沙:中南大学出版社, 2009.
[2] Li S, Zhang Y, Qi L, et al. Effect of single tensile overload on fatigue crack growth behavior in DP780 dual phase steel[J]. International Journal of Fatigue, 2018, 106:49-55.
[3] 岑耀东,陈芙蓉.超声冲击处理冷轧钢板缝焊接头的疲劳性能[J].焊接学报, 2017, 38(6):115-119 Cen Yaodong, Chen Furong. Fatigue performance improvement of SPCC steel resistance seam welding by ultrasonic impact treatment[J]. Transactions of the China Welding Institution, 2017, 38(6):115-119
[4] Nelson D V, Long Z. Bending fatigue of carburized steel at very long lives[J]. Journal of Materials Engineering&Performance, 2015, 25(1):1-7.
[5] Rui F M, Ferreira L, Reis L, et al. Fatigue crack growth under cyclic torsional loading[J]. Theoretical&Applied Fracture Mechanics, 2016, 85:56-66.
[6] 修俊杰,李杨,张潇予.径向间隙对304L不锈钢振动疲劳性能的影响[J].焊接学报, 2017, 38(8):95-98 Xiu Junjie, Li Yang, Zhang Xiaoyu. Research on radial gap of 304L stainless steel piping with socket weld under vibration fatigue[J]. Transactions of the China Welding Institution, 2017, 38(8):95-98
[7] 朴钟宇,徐滨士,王海斗,等.表征涂层接触疲劳寿命方法的试验研究[J].中国机械工程, 2009, 20(13):1616-1618 Piao Zhongyu, Xu Binshi, Wang Haidou, et al. Investigation of characterization method for the contact fatigue-life of coating[J]. China Mechanical Engineering, 2009, 20(13):1616-1618
[8] 魏建军,潘健,黄智泉,等.耐磨堆焊材料在水泥工业的应用现状及发展前景[J].中国表面工程, 2009, 22(5):8-12 Wei Jianjun, Pan Jian, Huang Zhiquan, et al. The applying actuality and developing foreground of hardfacing materials in cement industry[J]. China Surface Engineering, 2009, 22(5):8-12
[9] 李庆华,黄博滔,周宝民,等.超高韧性水泥基复合材料单轴压缩疲劳性能研究[J].建筑结构学报, 2016, 37(1):135-142 Li Qinghua, Huang Botao, Zhou Baomin, et al. Study on compression fatigue properties of ultra high toughness cementitious composites[J]. Journal of Building Structures, 2016, 37(1):135-142
[10] 姚宁,尹东海,张广泰,等.橡胶压缩疲劳性能的研究[J].橡胶科技, 2015, 13(7):19-22 Yao Ning, Yin Donghai, Zhang Guangtai, et al. Compression fatigue properties of different rubber materials[J]. Rubber Science and Technology, 2015, 13(7):19-22
[11] 景玉龙,杜华太,江美娟,等.定载荷下MWNTs/NR复合材料动态压缩疲劳性能研究[J].弹性体, 2015(2):44-49 Jing Yulong, Du Huatai, Jiang Meijuan, et al. Research on the dynamic compressive fatigue property of MWNTs/NR composite in certain load[J]. China Elastomerics, 2015(2):44-49
[12] 陈汉林.水泥挤压辊堆焊层抗疲劳性能研究[D].长春:吉林大学, 2017.
[13] 王璞,董建新,张麦仓,等. GH864合金蠕变/疲劳裂纹扩展速率及a-N曲线分析[J].稀有金属材料与工程, 2011, 40(4):630-634 Wang Pu, Dong Jianxin, Zhang Maicang, et al. Analysis of fatigue/creep crack propagations rates and a-N curves of GH864 alloy[J]. Rare Metal Materials and Engineering, 2011, 40(4):630-634
[14] 刘新东,郝际平.连续介质损伤力学[M].北京:国防工业出版社, 2011.
