Comparison of short fatigue crack behaviors for LZ50 axle steel under two loading frequencies
-
摘要: 在加载频率为180、15Hz条件下, 分别利用高频疲劳试验机和电液伺服疲劳试验机完成了各6根光滑漏斗形圆棒试样的短裂纹复型试验。试验结果表明: 在微观短裂纹(MSC) 阶段, 主导短裂纹的扩展均经历2次显著的减速过程, 在加载频率为180Hz, 扩展率降至最小值时, 裂纹统计平均尺度分别为11.49、106.32μm, 在15Hz下分别为14.14、122.29μm; 考虑试样个体间不可避免地存在微观结构细节差异, 从统计角度出发, 可以认为2次减速完成时的裂纹尺度分别对应铁素体晶粒平均直径14.26μm和富珠光体带状结构间距111.53μm这2种特征尺度; 进入物理短裂纹(PSC) 阶段后, 扩展率随主导短裂纹尺度增加持续上升; 2种加载频率下主导短裂纹扩展率曲线和密度曲线在很大程度上相互重合, 变化趋势一致, 整体来看无显著差异; 在MSC阶段, 低加载频率下的短裂纹扩展率略高于高加载频率下的结果, 但差异并不明显, 最大速率差未超过一个数量级; 加载频率15Hz下短裂纹突破微观组织结构障碍消耗的寿命占总寿命比例较小, 2次降速对应的平均寿命分数分别为0.027和0.525, 而180Hz下对应的寿命分数分别为0.071和0.688;通过统计分析, 对比了7种常用统计分布, 确定了主导短裂纹尺度服从极大值分布, 疲劳寿命分数和有效短裂纹密度服从极小值分布。Abstract: Under the loading frequencies of 180 and 15 Hz, short fatigue crack replica tests of six hourglass shaped specimens were carried out by using the high-frequency fatigue testing machine and the electrohydraulic servo fatigue testing machine, respectively.Test result shows that, at the microstructural short crack (MSC) stage, the growth of dominant short crack experiences two significant reduction processes.According to the two lowest growth rates, the statistical average crack sizes under the loading frequency of 180 Hz are 11.49 and 106.32μm, respectively, while the sizes under 15 Hz are 14.14 and 122.29μm, respectively.In consideration of the inevitable microstructural differences among the specimens, it is believed that the two main dominant crack growth rates decrease when the crack sizes are close to the average diameter 14.26μm of ferrite grains and to the average interval 111.53 μm of rich pearlite banded structures, respectively.At the physical short crack (PSC) stage, the growth rate of dominant short crack accelerates continuously with the increase of its size.The growth rate curves and density curves of dominant short crack under two loading frequencies overlap to a great extent and have the same change trends.In general, no significant differences exist.The growth rate of dominant short crack is slightly higher under low loading frequency than under high loading frequency at the MSC stage, but the difference is unobvious and less than a magnitude.The consumption life accounts for a smaller proportion of total life when the dominant crack breaks through the obstacles of microstructures, the fatigue life fractions are 0.027 and 0.525 under 15 Hz, respectively, and are0.071 and 0.688 under 180 Hz in the two significant reduction processes of dominant short crack growth.Based on 7 commonly used statistical distributions and comparative analysis, the distributions of size, fatigue life fraction and effective density of dominant short crack are determined, the size obeys the maximum distribution, and the fatigue life fraction and effective short crack density obey the minimum distribution.
-
Key words:
- vehicle engineering /
- LZ50 axle steel /
- fatigue short crack /
- loading frequency /
- growth rate
-
图 6 车轴钢短裂纹复型试验疲劳断口
Figure 6. Fatigue fractures of LZ50axle steel after short crack replica test
图 10 疲劳寿命分数的极小值累积分布曲线
Figure 10. Minimum cumulative distribution curves of fatigue life fraction
图 11 有效短裂纹密度的极小值累积分布曲线
Figure 11. Minimum cumulative distribution curves of effective short crack density
图 9 主导短裂纹尺度的极大值累积分布曲线
Figure 9. Maximum cumulative distribution curves of dominant short crack size
-
[1] YANG Bing, MA Bai-quan, ZHAO Yong-xiang, et al. Short fatigue crack growth at different maintenance times for LZ50steel[J]. Strength of Materials, 2015, 47 (1): 114-121. doi: 10.1007/s11223-015-9636-0 [2] MILLER K J. The short crack problem[J]. Fatigue and Fracture of Engineering Materials and Structures, 1982, 5 (3): 223-232. doi: 10.1111/j.1460-2695.1982.tb01250.x [3] 王正, 谭伟同, 王璐, 等. 高温低周疲劳短裂纹萌生的数值模拟[J]. 机械工程材料, 2014, 38 (3): 90-95. https://www.cnki.com.cn/Article/CJFDTOTAL-GXGC201403021.htmWANG Zheng, TAN Wei-tong, WANG Lu, et al. Numerical simulation of low-cycle short fatigue crack initiation at high temperature[J]. Materials for Mechanical Engineering, 2014, 38 (3): 90-95. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GXGC201403021.htm [4] PEARSON S. Initiation of fatigue cracks in commercial aluminium alloys and the subsequent propagation of very short cracks[J]. Engineering Fracture Mechanics, 1975, 7: 235-247. doi: 10.1016/0013-7944(75)90004-1 [5] LANKFORD J. The growth of small fatigue cracks in 7075-T6aluminium[J]. Fatigue and Fracture of Engineering Materials and Structures, 1982, 5 (3): 233-248. doi: 10.1111/j.1460-2695.1982.tb01251.x [6] 洪友士, 方飚. 疲劳裂纹萌生及发展的细观过程和理论[J]. 力学进展, 1993, 23 (4): 468-486. https://www.cnki.com.cn/Article/CJFDTOTAL-LXJZ199304001.htmHONG You-shi, FANG Biao. Microscopic process and description for the initiation and propagation of short fatigue cracks[J]. Advances in Mechanics, 1993, 23 (4): 468-486. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-LXJZ199304001.htm [7] HYSPECKY P, STRNADEL B. Conversion of short fatigue cracks into a long crack[J]. Fatigue and Fracture of Engineering Materials and Structures, 1992, 15 (9): 845-854. doi: 10.1111/j.1460-2695.1992.tb00061.x [8] MACADRE A, ARTAMONOV M, MATSUOKA S, et al. Effects of hydrogen pressure and test frequency on fatigue crack growth properties of Ni-Cr-Mo steel candidate for a storage cylinder of a 70 MPa hydrogen filling station[J]. Engineering Fracture Mechanics, 2011, 78: 3196-3211. doi: 10.1016/j.engfracmech.2011.09.007 [9] 付正鸿, 陈辉, 苟国庆, 等. 载荷频率对690 (TT) 合金腐蚀疲劳裂纹扩展行为的影响[J]. 材料热处理学报, 2016, 37 (2): 36-41. https://www.cnki.com.cn/Article/CJFDTOTAL-JSCL201602007.htmFU Zheng-hong, CHEN Hui, GOU Guo-qing, et al. Effect of frequency on corrosion fatigue crack growth behavior of 690 (TT) alloy[J]. Transactions of Materials and Heat Treatment, 2016, 37 (2): 36-41. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JSCL201602007.htm [10] STAEHLER J M, MALL S, ZAWADA L P. Frequency dependence of high-cycle fatigue behavior of CVI C/SiC at room temperature[J]. Composites Science and Technology, 2003, 63 (15): 2121-2131. doi: 10.1016/S0266-3538(03)00190-8 [11] 张亚军. 加载频率与应变比对10CrNi5Mo高强钢低周疲劳寿命的影响[J]. 理化检验—物理分册, 2010, 46 (3): 164-170. https://www.cnki.com.cn/Article/CJFDTOTAL-LHJW201003009.htmZHANG Ya-jun. Effect of loading frequency and strain ratio on low cycle fatigue life of 10CrNi5Mo high strength steel[J]. Physical Testing and Chemical Analysis Part A: Physical Testing, 2010, 46 (3): 164-170. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-LHJW201003009.htm [12] MAYER H, PAPAKYRIACOU M, PIPPAN R, et al. Influence of loading frequency on the high cycle fatigue properties of AlZnMgCu1.5aluminum alloy[J]. Materials Science and Engineering: A, 2001, 314 (1/2): 48-54. [13] 邓彩艳, 王红, 龚宝明, 等. 加载频率及焊接缺陷对5A06铝合金TIG焊接头超高周疲劳性能的影响[J]. 焊接学报, 2015, 36 (12): 61-64. https://www.cnki.com.cn/Article/CJFDTOTAL-HJXB201512015.htmDENG Cai-yan, WANG Hong, GONG Bao-ming, et al. Effects of loading frequency and welding defects on very-highcycle fatigue properties of 5A06aluminum alloy TIG welded joints[J]. Transactions of the China Welding Institution, 2015, 36 (12): 61-64. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-HJXB201512015.htm [14] SAKAMOTO H, TAKEZONO S, NAKANO T. Effect of stress frequency on fatigue crack initiation in titanium[J]. Engineering Fracture Mechanics, 1988, 30 (3): 373-382. doi: 10.1016/0013-7944(88)90195-6 [15] 翟婉明, 金学松, 赵永翔. 高速铁路工程中若干典型力学问题[J]. 力学进展, 2010, 40 (4): 358-374. https://www.cnki.com.cn/Article/CJFDTOTAL-LXJZ201004003.htmZHAI Wan-ming, JIN Xue-song, ZHAO Yong-xiang. Some typical mechanical problems in high-speed railway engineering[J]. Advances in Mechanics, 2010, 40 (4): 358-374. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-LXJZ201004003.htm [16] 杨冰. LZ50车轴钢的随机疲劳短裂纹行为研究[D]. 成都: 西南交通大学, 2010.YANG Bing. Study on the random short fatigue crack behavior of LZ50axle steel[D]. Chengdu: Southwest Jiaotong University, 2010. (in Chinese). [17] 赵永翔. 低周疲劳短裂纹行为和可靠性分析[D]. 成都: 西南交通大学, 1998.ZHAO Yong-xiang. Short behaviour and reliability analysis in low cycle fatigue[D]. Chengdu: Southwest Jiaotong University, 1998. (in Chinese). [18] 赵永翔, 高庆, 王金诺. 不锈钢管道焊缝金属疲劳短裂纹行为的试验研究I—材料微观结构和研究方法[J]. 金属学报, 2000, 36 (9): 931-936. doi: 10.3321/j.issn:0412-1961.2000.09.007ZHAO Yong-xiang, GAO Qing, WANG Jin-nuo. Experimental observations on the short fatigue crack behaviour of a stainless steel pipe-weld metal I—material microstructures and research approach[J]. Acta Metallurgica Sinica, 2000, 36 (9): 931-936. (in Chinese). doi: 10.3321/j.issn:0412-1961.2000.09.007 [19] ZHAO Yong-xiang, GAO Qing, WANG Jin-nuo. Interaction and evolution of short fatigue cracks[J]. Fatigue and Fracture of Engineering Materials and Structures, 1999, 22 (6): 459-467. doi: 10.1046/j.1460-2695.1999.00195.x [20] 杨冰, 赵永翔. 表面滚压对LZ50车轴钢疲劳短裂纹行为的影响[J]. 金属学报, 2012, 48 (8): 922-928. https://www.cnki.com.cn/Article/CJFDTOTAL-JSXB201208005.htmYANG Bing, ZHAO Yong-xiang. Influence of surface rolling on short fatigue crack behavior for LZ50axles steel[J]. Acta Metallurgica Sinica, 2012, 48 (8): 922-928. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JSXB201208005.htm [21] MILLER K J. The behaviour of short fatigue cracks and their initiation, PartⅠ—A review of two recent books[J]. Fatigue and Fracture of Engineering Materials and Structures, 1987, 10 (1): 75-91. doi: 10.1111/j.1460-2695.1987.tb01150.x [22] MILLER K J. The behaviour of short fatigue cracks and their initiation, PartⅡ—A general summary[J]. Fatigue and Fracture of Engineering Materials and Structures, 1987, 10 (2): 93-113. doi: 10.1111/j.1460-2695.1987.tb01153.x [23] 赵永翔, 高庆, 王金诺. 不锈钢管道焊缝金属疲劳短裂纹行为的试验研究Ⅱ—裂纹萌生、扩展与交互作用[J]. 金属学报, 2000, 36 (9): 937-943. doi: 10.3321/j.issn:0412-1961.2000.09.008ZHAO Yong-xiang, GAO Qing, WANG Jin-nuo. Experimental observations on the short fatigue crack behaviour of a stainless steel pipe-weld metalⅡ—crack initiation, growth and interaction[J]. Acta Metallurgica Sinica, 2000, 36 (9): 937-943. (in Chinese). doi: 10.3321/j.issn:0412-1961.2000.09.008 [24] 赵永翔, 杨冰, 高庆. 1Cr18Ni9Ti管道焊缝金属疲劳短裂纹萌生与早期扩[J]. 核动力工程, 2003, 24 (2): 127-132 https://www.cnki.com.cn/Article/CJFDTOTAL-HDLG200302006.htmZHAO Yong-xiang, YANGBing, GAO Qing. Initiation and early propagation of short fatigue cracks on weld metal of 1Cr18Ni9Ti pipes[J]. Nuclear Power Engineering, 2003, 24(2): 127-132(in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-HDLG200302006.htm [25] 赵永翔, 杨冰, 高庆. 1Cr18Ni9Ti管道焊缝金属的物理疲劳短裂纹扩展试验研究[J]. 核动力工程, 2005, 26 (6): 579-584. doi: 10.3969/j.issn.0258-0926.2005.06.012ZHAO Yong-xiang, YANG Bing, GAO Qing. Experiment of physical short fatigue crack propagation of 1Cr18Ni9Ti weld metal[J]. Nuclear Power Engineering, 2005, 26 (6): 579-584. (in Chinese). doi: 10.3969/j.issn.0258-0926.2005.06.012 [26] 赵永翔, 孙亚芳, 高庆. 分析常用7种统计分布的统一线性回归方法[J]. 机械强度, 2001, 23 (1): 102-106. doi: 10.3321/j.issn:1001-9669.2001.01.028ZHAO Yong-xiang, SUN Ya-fang, GAO Qing. Unfied linear regression method for the analysis of seven commonly used statistical distributions[J]. Journal of Mechanical Strength, 2001, 23 (1): 102-106. (in Chinese). doi: 10.3321/j.issn:1001-9669.2001.01.028 [27] 赵永翔, 王金诺, 高庆. 确定有限疲劳可靠性数据良好假设分布的一种统一方法[J]. 中国机械工程, 2001, 12 (12): 1343-1347. doi: 10.3321/j.issn:1004-132X.2001.12.005ZHAO Yong-xiang, WANG Jin-nuo, GAO Qing. Unfied approach for determining an appropriate assumed distribution of limited fatigue reliability data[J]. China Mechanical Engineering, 2001, 12 (12): 1343-1347. (in Chinese). doi: 10.3321/j.issn:1004-132X.2001.12.005 -
下载:
点击查看大图
图(11) / 表(5)
计量
- 文章访问数: 321
- HTML全文浏览量: 63
- PDF下载量: 366
- 被引次数: 0
