25CrMnB履带钢冲裁断裂成因分析

doi:10.13251/j.issn.0254-6051.2021.12.047

摘要/Abstract

摘要： 通过金相和硬度试验,研究了25CrMnB履带钢不同部位组织与硬度的分布规律,对热轧25CrMnB履带钢出现冲裁断裂问题的原因进行了分析。结果表明,水冷样品比空冷样品硬度更高,且诱导齿处易出现硬度偏高的问题,断裂首先于诱导齿处发生。履带钢冲裁断裂的原因是出现了混晶组织、网状铁素体和粒状贝氏体组织,材料受力时在异常组织处形成应力集中,导致微裂纹萌生并扩展,引起履带钢冲裁时开裂。混晶组织与网状铁素体出现的原因是终轧温度过高。根据EDS分析结果,粒状贝氏体出现的原因主要是Mn和B元素微观偏析。

关键词: 25CrMnB履带钢, 异常组织, 粒状贝氏体, 硬度分布

Abstract: Distribution law of microstructure and hardness of different parts in the 25CrMnB track steel was studied by means of metallographic and hardness tests, and the cause of blanking fracture of hot-rolled 25CrMnB track steel was analyzed. The results show that the hardness of the water-cooled specimen is higher than that of the air-cooled specimen, and the hardness of the inducing tooth parts of the track steel where the failure occurs firstly is more likely to be abnormally high. The reason of blanking fracture of the track steel is the appearance of mixed grain structure, reticular ferrite and granular bainite. High stress concentration could occur at the abnormal microstructure when the material is stressed, which leads to the initiation and propagation of microcracks and the blanking failure of track steel. The reason for the appearance of mixed grain structure and reticular ferrite is too high final rolling temperature. On the basis of EDS analysis, the main reason for the appearance of granular bainite is the segregation of microscopic elements of Mn and B.

Key words: 25CrMnB track steel, abnormal microstructure, granular bainite, hardness distribution

中图分类号:

TG142.1

田雨, 于浩. 25CrMnB履带钢冲裁断裂成因分析[J]. 金属热处理, 2021, 46(12): 282-288.

Tian Yu, Yu Hao. Blanking failure analysis of 25CrMnB track steel[J]. Heat Treatment of Metals, 2021, 46(12): 282-288.

参考文献

[1]邓通武. 钒对25CrMnB钢履带板耐磨性能的影响[J]. 特殊钢, 2019, 40(5): 67-70.
Deng Tongwu. Effect of vanadium on wear resistance of track shoe of steel 25CrMnB[J]. Special Steel, 2019, 40(5): 67-70.
[2]赵基, 杜超. 25MnB履带板用钢的热处理工艺[J]. 金属热处理, 2015, 40(10): 192-194.
Zhao Ji, Du Chao. Heat treatment process of 25MnB steel track board[J]. Heat Treatment of Metals, 2015, 40(10): 192-194.
[3]张群, 王德勇, 阚开. 连续冷却速度对挖掘机履带用钢15B36-M相变和显微组织的影响[J]. 金属热处理, 2020, 45(5): 115-118.
Zhang Qun, Wang Deyong, Kan Kai. Effect of continuous cooling rate on phase transformation and microstructure of 15B36-M track steel for excavator[J]. Heat Treatment of Metals, 2020, 45(5): 115-118.
[4]邓通武. 25CrMnB钢228节距履带的热处理工艺[J]. 金属热处理, 2012, 37(12): 89-91.
Deng Tongwu. Heat treatment process of 25CrMnB steel 228 pitch crawler belt[J]. Heat Treatment of Metals, 2012, 37(12): 89-91.
[5]朱鹏霄, 李毅, 冯坤, 等. 淬火温度对25CrMnB钢组织与性能的影响[J]. 金属热处理, 2018, 43(1): 175-178.
Zhu Pengxiao, Li Yi, Feng Kun, et al. Effect of quenching temperature on microstructure and properties of 25CrMnB steel[J]. Heat Treatment of Metals, 2018, 43(1): 175-178.
[6]康永林, 朱国明. 大型H型钢轧制过程数值模拟及应用[J]. 山东冶金, 2009, 31(5): 1-4.
Kang Yonglin, Zhu Guoming. Large size H-beams rolling process numerical simulation and application[J]. Shandong Metallurgy, 2009, 31(5): 1-4.
[7]程鼎, 薛东妹, 潘涛, 等. 微合金化H型钢轧后空冷的温度场及组织和性能[J]. 钢铁研究学报, 2009, 21(7): 33-36.
Cheng Ding, Xue Dongmei, Pan Tao, et al. Temperature field of microalloyed H beam after hot rolling and its influence on microstructure and mechanical performance[J]. Journal of Iron and Steel Research, 2009, 21(7): 33-36.
[8]祖方遒. 材料成形基本原理[M]. 北京: 机械工业出版社, 2010.
[9]霍建生, 阎冬. 700 MPa级高强度耐候钢过冷奥氏体连续冷却相变行为[J]. 金属热处理, 2021, 46(7): 94-98.
Huo Jiansheng, Yan Dong. Continuous cooling transformation behavior of undercooled austenite of 700 MPa high strength weathering resistance steel[J]. Heat Treatment of Metals, 2021, 46(7): 94-98.
[10]Taylor K A. Grain-boundary segregation and precipitation of boron in 0.2 percent carbon steels[J]. Metallurgical and Materials Transactions A, 1992, 23(1): 107-119.
[11]李晓鹏, 党孟军, 张艳芳. 网状铁素体对盘条性能的影响[J]. 金属制品, 1999(2): 29-31.
Li Xiaopeng, Dang Mengjun, Zhang Yanfang. Effect of ferrite net on the mechanical properties of wire rods[J]. Steel Wire Products, 1999(2): 29-31.
[12]Mazancová E, Mazanec K. Physical metallurgy characteristics of the M/A constituent formation in granular bainite[J]. Journal of Materials Processing Technology, 1997, 64(1): 287-292.
[13]Chen J, Tang S, Liu Z Y, et al. Microstructural characteristics with various cooling paths and the mechanism of embrittlement and toughening in low-carbon high performance bridge steel[J]. Materials Science and Engineering A, 2013, 559: 241-249.
[14]Tian D, Karjalainen L P, Qian B, et al. Cleavage fracture model for granular bainite in simulated coarse-grained heat-affected zones of high-strength low-alloyed steels[J]. JSME International Journal, 1997, 40(2): 179-188.
[15]Luo Yi, Peng Jinmin, Wang Hongbin, et al. Effect of tempering on microstructure and mechanical properties of a non-quenched bainitic steel[J]. Materials Science and Engineering A, 2010, 527(15): 3433-3437.
[16]徐祖耀. 低锰钢的锰偏析[M]. 北京: 冶金工业出版社, 1979.
[17]许映, 刘涛, 龙威, 等. B+级铸钢中粒状贝氏体的形成原因分析[J]. 材料热处理学报, 2019, 40(8): 105-109.
Xu Ying, Liu Tao, Long Wei, et al. Cause analysis of granular bainite formation in B+grade cast steel[J]. Transactions of Materials and Heat Treatment, 2019, 40(8): 105-109.
[18]裴丙红, 张红斌, 曹美姣, 等. 论GH901合金真空熔炼铸锭中硼的宏观偏析[J]. 特钢技术, 2006, 12(3): 5-13.
Pei Binghong, Zhang Hongbin, Cao Meijiao, et al. Argumentation on themacrosegregation of boron in vacuum melting pouring ingot of GH901 alloy[J]. Special Steel Technology, 2006, 12(3): 5-13.
[19]冉旭, 陈莉, 邬占田, 等. 20CrMnTi钢粒状贝氏体的消除[J]. 吉林工学院学报, 1999, 20(2): 15-20.
Ran Xu, Chen Li, Wu Zhantian, et al. Elimination of granular bainite in 20CrMnTi steel[J]. Journal of Jilin Institute of Technology, 1999, 20(2): 15-20.