锻压技术

中碳微合金非调质钢36MnVS4连杆胀断缺陷分析

英文标题：Analysis on bulging fracture defects for medium carbon microalloy non-quenched and tempered steel 36MnVS4 connecting rod

作者：黄博远董帅君孙建林张朝磊

单位：北京科技大学材料科学与工程学院

关键词：非调质钢胀断加工掉渣断口不齐控锻控冷技术

分类号：TG142.1

出版年,卷(期):页码：2023,48(7):228-233

摘要：

通过合金成分分析、显微组织定量表征、断口形貌观察及力学性能测定，对中碳微合金非调质钢36MnVS4连杆断口掉渣和断口不齐缺陷进行分析。在VW 50030标准和TCCMI 13.1—2021标准下进行比较，结果表明：4支连杆组织为珠光体+铁素体，均无异常组织，晶粒度均为5.5~6.0级，不符合标准要求；缺陷连杆的抗拉强度、屈服强度、断后伸长率符合标准，但断面收缩率为26.5%~27.4%，明显低于合格连杆的32.8%~33.5%的断面收缩率，未达到要求。断口不齐的主要原因为断口附近的Ca、Si氧化物夹杂物，在断口侧面发现激光切槽的位置较深，不仅改变胀断轨迹，还降低断面收缩率；掉渣的主要原因为断口附近出现微孔型断裂韧窝，改变了断口表面状态。最后提出采用控锻控冷技术精确控制组织性能是解决问题的关键。

Through analysis of alloy composition, quantitative characterization of microstructure, observation of fracture morphology and measurement of mechanical properties, the slag dropping at fracture and irregular fracture defects of medium carbon microalloy non-quenched and tempered steel 36MnVS4 connecting rod were analyzed. Under VW 50030 and TCCMI 13.1—2021 standards, the results show that the structures of four connecting rods are pearlite+ferrite without abnormal structure, and the grain size is all Grade 5.5-6.0, which does not meet the standard requirements. The tensile strength, yield strength and elongation after fracture of the defective connecting rods meet the standards, but the section shrinkage is 26.5%-27.4%, which is significantly lower than that (32.8%-33.5%) of the qualified connecting rods and does not meet the requirements. The main reason of irregular fracture is the Ca and Si oxide inclusions near the fracture. The position of laser cut groove is found to be deep on the side of fracture, which not only changes the bulging fracture trajectory, but also reduces the section shrinkage. The main reason of slag dropping is that microporous fracture dimples appears near the fracture, which changes the surface state of fracture. Finally, it is proposed that the use of thermo mechanical control process to accurately control the microstructure and properties is the key to solve the problem.

基金项目：

作者简介：黄博远（1996-），男，博士研究生 E-mail：597707542@qq.com 通信作者：张朝磊（1984-），男，博士，副教授 E-mail：zhangchaolei@ustb.edu.cn

参考文献：

[1]陈蕴博，马鸣图，王国栋.汽车用非调质钢的研究进展[J].中国工程科学，2014，16(2)：4-17.

Chen Y B, Ma M T, Wang G D. Resent progress of nonquenched and tempered steel for automotive sheet [J]. Strategic Study of CAE, 2014, 16(2): 4-17.

[2]Gu Z, Yang S, Ku S, et al. Fracture splitting technology of automobile engine connecting rod [J]. The International Journal of Advanced Manufacturing Technology, 2005, 25: 883-887.

[3]宋晓磊，李杨.发动机连杆裂解加工新技术[J].现代制造技术与装备，2017，(6)：140-142.

Song X L, Li Y. New technology for splitting cracking of engine connecting rod [J]. Modern Manufacturing Technology and Equipment, 2017, (6): 140-142.

[4]张朝磊，刘雅政.汽车胀断连杆用非调质钢的应用现状与发展[J].材料导报，2017，31(5)：58-64.

Zhang C L, Liu Y Z. Application and development of aircooled forging steel for automotive fracture splitting connecting rod [J]. Materials Reports, 2017, 31(5): 58-64.

[5]Li J R, Ji Y, Liu Y Z, et al. Effects of austenitizing temperature and cooling rate on the mechanical properties of 36MnVS4 steel for automobile engine connecting rod [J]. Materials Science Forum, 2017, 898: 1195-1197.

[6]张朝磊，胡佳丽，李戬，等.胀断连杆用非调质钢C70S6的材料特性及组织性能控制[J].材料导报，2020，34（S1）：444-447.

Zhang C L, Hu J L, Li J, et al. Characteristic and properties control of aircooled forging steel C70S6 for fracture splitting connecting rod [J]. Materials Reports, 2020, 34（S1）: 444-447.

[7]师周龙，邵成伟，惠卫军，等.连杆用36MnVS4钢的胀断性能[J].钢铁研究学报，2014，26(4)：42-45.

Shi Z L, Shao C W, Hui W J, et al. Fracture splitting properties of steel 36MnVS4 for connecting rod [J]. Journal of Iron and Steel Research, 2014, 26(4): 42-45.

[8]李晓辉，张朝磊，李戬，等.国产非调质钢 36MnVS4 连杆胀断缺陷分析[J].塑性工程学报，2018，25(1)：151-155.

Li X H, Zhang C L, Li J, et al. Analysis for fracture splitting defect of domestic ailcooled forging steel 36MnVS4 connecting rod [J]. Journal of Plasticity Engineering, 2018, 25(1):151-155.

[9]张朝磊，魏旸，方文，等.非调质钢36MnVS4汽车发动机连杆胀断缺陷分析[J].材料导报，2018，32(14)：2458-2461.Zhang C L, Wei Y, Fang W, et al. Fracture splitting defects analysis of automotice connecting rod made of aircooled forging steel 36MnVS4[J].Materials Reports, 2018, 32(14): 2458-2461.

[10]VW 50030，VOLKWAGEN Pleuelstangen[S].

[11]T/CCMI 13.1—2021，发动机胀断连杆毛坯技术条件第1部分：乘用车发动机胀断连杆[S].

T/CCMI 13.1—2021，Technical specification for the fracture splitting connecting rod blank of engine—Part 1：The fracture splitting connecting rod for passenger vehicle[S].

[12]赵静.发动机连杆裂解后大端孔变形量的影响因素分析[J].汽车工艺师，2019，(12)：37-40.

Zhao J. Analysis of the factors influencing the deformation of the large end hole of the engine connecting rod after cracking [J]. Auto Manufacturing Engineer, 2019, (12): 37-40.

[13]苏培林，程焱，王冠，等.激光加工胀断连杆裂解槽技术研究现状[J].激光与光电子学进展，2021，58(11)：59-67.

Su P L, Cheng Y, Wang G, et al. Research status of laser processing technology of broken connecting rod cracking groove [J]. Laser & Optoelectronics Progress, 2021, 58(11): 59-67.

[14]孟凡荣，单淑梅，冯炳瑞.连杆胀断机激光切槽问题分析与改进[J].制造技术与机床，2015，(5)：136-137.

Meng F R, Shan S M, Feng B R. Analysis and improvement of laser grooving problem for connecting rod cracking machine [J]. Manufacturing Technology & Machine Tool, 2015, (5): 136-137.

[15]邓军伟，徐俊峰，姜增强，等.胀断MC11H连杆横向断面收缩率低的原因[J].理化检验-物理分册，2022，58(1)：57-61.

Deng J W, Xu J F, Jiang Z Q, et al. Cause of low transverse percentage reduction of areashrinkage of fracture MC11H connecting rod [J]. Physical Testing and Chemical Analysis, Part A: Physical Testing, 2022, 58(1): 57-61.

[16]Danilov S V, Khotinov V A, Urtsev N V, et al. Influence of crystallographic texture of TMCP pipe steel on the nature of deformation and fracture during tensile testing [J]. Procedia Structural Integrity, 2022, 40: 112-117.

[17]刘江，徐皓，杨德行，等．38MnVS非调质钢活塞锻后控制冷却工艺[J]．锻压技术，2022，47(1)：180-184，202．

Liu J，Xu H，Yang D H，et al. Controlled cooling process of 38MnVS non-quenched and tempered steel piston after forging[J]. Forging & Stamping Technology, 2022, 47(1): 180-184, 202.

[18]陈思联，董瀚，徐乐，等.适合性能差异化控制的高强度非调质钢及锻件制造方法[P].中国：CN201510812376.7,2016-03-02.

Chen S L, Dong H, Xu L, et al. Highstrength nonquenched and tempered steel and forging manufacturing methods suitable for performance differentiation control[P].China: CN201510812376.7, 2016-03-02.

服务与反馈：

【本网站尚未开通全文下载服务】【加入收藏】