Cause analysis on quenching cracking of 40CrNiMo7 steel forged shaft

doi:10.13251/j.issn.0254-6051.2021.02.040

Abstract

Abstract: Causes of 40CrNiMo7 steel forged shaft cracking were analyzed by means of macroscopic morphology observation, chemical composition analysis, hardness test, metallographic analysis, energy spectrum analysis and other methods. The results show that the crack of the forged shaft is a longitudinal quenching crack, due to that the Cr element in the steel exceeds the standard, and increases the cracking tendency. The specimen surface has more TiN inclusions and Al₂O₃, MnS etc., and a decarburized layer of about 0.6 mm, which promotes the formation of cracks. The generated structural stress during quenching causes the surface to exhibit a tensile stress state, and with the help of decarburized layer and non-metallic inclusions, the fracture strength of the material is exceeded and cracking occurs.

Key words: 40CrNiMo7 steel, quenching cracking, structural stress, decarburized layer, inclusions

CLC Number:

TG156.35

Zhang Jiawen, Fu Tianliang, Wu Hao, Wang Zhaodong. Cause analysis on quenching cracking of 40CrNiMo7 steel forged shaft[J]. Heat Treatment of Metals, 2021, 46(2): 213-217.

References

[1] 王敬忠,李科元,刘阿娇,等.40CrNiMo钢国内外研究现状[J].钢铁,2018,53(5):1-10.
Wang Jingzhong,Li Keyuan,Liu Ajiao,et al.Research status of 40CrNiMo steel at home and abroad[J].Iron and Steel,2018,53(5):1-10.
[2] 钟德惠,孙熙钟.浅析淬火裂纹产生的原因及防止措施[J].科技风,2013(8):39.
[3] 刘玉,左训伟,陈乃录,等.淬火纵向裂纹的有限元模拟[J].材料热处理学报,2019,40(3):160-167.
Liu Yu,Zuo Xunwei,Chen Nailu,et al.Finite element simulation of longitudinal quenching crack[J].Transactions of Materials and Heat Treatment,2019,40(3):160-167.
[4] 姜如松,廖永红.40CrMnMo钢单体泵泵体淬火开裂分析及对策[J].金属热处理,2016,41(12):187-191.
Jiang Rusong,Liao Yonghong.Quenching crack analysis and counter measures of 40CrMnMo steel single pump body[J].Heat Treatment of Metals,2016,41(12):187-191.
[5] 《钢的热处理裂纹和变形》编写组编.钢的热处理裂纹和变形[M].北京:机械工业出版社,1978:48-50.
[6] 刘进益.热处理裂纹分析—典型淬火裂纹[J].东方电机,2009,37(1):44-51.
[7] 邹中秋,马爱斌,宋丹,等.RM-2热作模具钢淬火开裂原因分析[J].金属热处理,2007,32(12):100-102.
Zou Zhongqiu,Ma Aibing,Song Dan,et al.Failure analysis on quenching cracking of RM-2 hot-working die steel[J].Heat Treatment of Metals,2007,32(12):100-102.
[8] 王大业,王明胜,雷艳.国产锰叉所取试样的多冲疲劳断裂过程的研究[J].西安建筑科技大学学报(自然科学版),1985(1):114-125.
Wang Daye,Wang Mingsheng,Lei Yan.Investigation onprocess of fatigue fracture of railroad frogs under repeated impact[J].Journal of Xi’an University of Science and Technology(Natural Science Edition),1985(1):114-125.
[9] 印小松,董旭刚,周兵,等.42CrMo曲轴裂纹原因分析及改进措施[J].金属加工(热加工),2016(11):78-80.
[10] 甘美露,张强,王书强,等.42CrMo钢蜗杆开裂原因分析[J].理化检验(物理分册),2020,56(2):39-43.
Gan Meilu,Zhang Qiang,Wang Shuqiang,et al.Cause analysis on cracking of 42CrMo steel worm[J].Physical Testing and Chemical Analysis(Part A:Physical Testing),2020,56(2):39-43.
[11] 平海凤.成功的热处理工艺—淬火裂纹的对策(二)[J].国外金属热处理,1998(5):13-15.
[12] 焦丽,陈德良,焦红倩,等.40Cr钢圆钢开裂原因分析[J].热处理,2018,33(2):44-48.
Jiao Li,Chen Deliang,Jiao Hongqian,et al.Analysis on cause for 40Cr steel round bar cracking[J].Heat Treatment,2018,33(2):44-48.
[13] 侯婷.8620H钢齿轮表面裂纹分析[J].金属热处理,2017,42(7):180-184.
Hou Ting.Analysis of surface crack on 8620H steel gear[J].Heat Treatment of Metals,2017,42(7):180-184.
[14] 纪嘉明,吴晶.水泵泵轴淬火裂纹分析[J].排灌机械,2004(5):20-22.
Ji Jiaming,Wu Jing.Analysis of quenching cracks of pump axle[J].Drainage and Irrigation Machinery,2004(5):20-22.

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