目的 分析并解决某家用汽车左后轮轮毂轴承单元五颗高强度螺栓在Vm工况（针对新研发汽车的路况测试）下全部断裂导致车轮脱落的问题。通过对失效螺栓进行系统研究,找出断裂的根本原因并提出切实可行的改进措施,以确保汽车轮毂螺栓的可靠性与安全性。方法 采用断口形貌观察、金相组织检测、化学成分分析、硬度测试、轴承螺栓牢固性能试验以及仿真验证等手段。通过与同批次未使用样件进行对比,分析断裂螺栓的失效机理。结果 因机械损伤引发应力集中,进而导致疲劳断裂,疲劳裂纹主要源于螺纹根部的表面损伤区域。具体的外部因素包括车轮多次拆装导致拧紧力矩不足（低于推荐值）以及未使用刹车盘定位孔导致螺栓应力集中。而内部因素则为螺栓材料中存在尺寸20~30 μm的夹杂物颗粒,降低了材料的疲劳强度,从而加速了螺栓的失效。结论 根据实验结果,总结了螺栓断裂的失效机理,发现疲劳裂纹的形成与外部拧紧力矩不足（主要原因）、刹车盘定位孔未规范使用以及螺栓材料中的夹杂物颗粒密切相关。一般耐久性试验结果表明,当拧紧力矩不足时,螺栓会过早断裂。而一般耐久性仿真分析结果表明,预紧力不足导致被夹紧件最大滑动距离增大。预紧力不足会增加微动磨损,引发螺栓机械损伤导致的疲劳断裂。为了防止类似事故的发生,提出了改进措施：严格按照标准力矩拧紧螺栓,并在重复拆装时适当提高拧紧力矩;规范使用刹车盘定位孔;优化冶炼工艺以减少夹杂物,并加强热处理质量控制,提升材料的均质性和疲劳强度。
Abstract
The work aims to analyze and address the failure of all five high-strength bolts in the left rear wheel hub bearing unit of a passenger vehicle, which fracture under Vm operating conditions (a road test for newly developed automobiles) and result in wheel detachment, identify the root cause of the fracture through systematic investigation of the failed bolts, and propose feasible improvement measures to ensure the reliability and safety of automotive wheel hub bolts. In this study, fracture surface morphology observation, metallographic analysis, chemical composition analysis, hardness testing, bearing bolt fastening performance tests, and simulation validation were employed. A comparison with unused samples from the same batch was made to analyze the failure mechanism of the fractured bolts. The fatigue failure was caused by stress concentration initiated by mechanical damage. The fatigue cracks primarily originated from surface damage at the thread root. Specific external factors included insufficient tightening torque (below the recommended value) due to multiple wheel removals and the failure to use the brake disc locating hole, leading to stress concentration in the bolts. Internal factors included the presence of inclusions of approximately 20-30 μm in size in the bolt material, which reduced the material's fatigue strength and accelerated bolt failure. Based on the experimental results, the failure mechanism of bolt fracture is summarized. It is found that the formation of fatigue fracture is closely related to insufficient external tightening torque (the main cause), improper use of brake disc positioning holes, and inclusion particles in the bolt material. The general durability test verifies that bolts would fracture prematurely when the tightening torque is insufficient. Meanwhile, the general durability simulation analysis confirms that insufficient preload leads to an increase in the maximum sliding distance of the clamped parts. It is concluded that insufficient preload will increase fretting wear, causing mechanical damage to the bolts and resulting in fatigue fracture. To prevent similar accidents, the study proposes the following improvement measures: strictly tighten bolts according to the standard torque, and appropriately increase the tightening torque during repeated disassembly and assembly; standardize the use of brake disc positioning holes; optimize the smelting process to reduce inclusions, and strengthen heat treatment quality control to improve material homogeneity and fatigue strength.
关键词
高强度螺栓 /
SCM435钢 /
断裂 /
拧紧力矩 /
预紧力
Key words
high-strength bolts /
SCM435 steel /
fracture /
tightening torque /
preload
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参考文献
[1] 蓝秀琼, 陈建华. 汽车用高强度组合螺栓断裂失效分析[J]. 机械强度, 2018, 40(5): 1263-1265.
LAN X Q, CHEN J H.Fracture Failure Analysis of a Auto High Strength Assembling Bolt[J]. Journal of Mechanical Strength, 2018, 40(5): 1263-1265.
[2] ZHAO L H, LI Q C, FENG J Z, et al.Service Life Prediction Method for Wheel-Hub-Bearing under Random Multi-Axial Wheel Loading[J]. Engineering Failure Analysis, 2021, 122: 105211.
[3] 李博, 胡伟叶, 沈以赴, 等. 飞机框架结构件振动疲劳失效分析[J]. 金属热处理, 2011, 36(9): 83-87.
LI B, HU W Y, SHEN Y F, et al.Vibration-Fatigue Failure Analysis of an Aircraft Frame Component[J]. Heat Treatment of Metals, 2011, 36(9): 83-87.
[4] 夏洪花, 陈荣, 封彤波, 等. 某发动机低压一级叶片裂纹失效分析[J]. 金属热处理, 2019, 44(S1): 243-245.
XIA H H, CHEN R, FENG T B, et al.Failure Analysis of Cracks on Low Pressure First Stage Blades of an Engine[J]. Heat Treatment of Metals, 2019, 44(S1): 243-245.
[5] KOPPISETTI S B, NALLU R, PENMETSA R R.Passenger Cars Wheel Performance Test Simulation for Service Life Evaluation: A Review[J]. Journal of Failure Analysis and Prevention, 2022, 22(4): 1370-1392.
[6] 吕源, 易聪, 周留成, 等. 1Cr15Ni4Mo3N不锈钢表面显微硬度演化与疲劳性能研究[J]. 精密成形工程, 2024, 16(12): 189-197.
LYU Y, YI C, ZHOU L C, et al.Surface Microhardness Evolution and Fatigue Properties of 1Cr15Ni4Mo3N Stainless Steel[J]. Journal of Netshape Forming Engineering, 2024, 16(12): 189-197.
[7] 李娜, 郑子行, 索晓娜. 高强度螺栓失效原因分析和预防措施[J]. 船舶工程, 2024, 46(S1): 235-238.
LI N, ZHENG Z H, SUO X N.Analysis of Failure Causes and Preventive Measures for High-Strength Bolts[J]. Ship Engineering, 2024, 46(S1): 235-238.
[8] 宋全, 曹辉辉, 张甜琪, 等. 液压工装螺栓断裂失效分析[J]. 金属热处理, 2024, 49(6): 301-304.
SONG Q, CAO H H, ZHANG T Q, et al.Fracture Failure Analysis of Hydraulic Equipment Bolts[J]. Heat Treatment of Metals, 2024, 49(6): 301-304.
[9] 王朴, 童辉. 35CrMo钢高强螺栓断裂失效分析[J]. 金属热处理, 2023, 48(5): 294-297.
WANG P, TONG H.Fracture Failure Analysis of 35CrMo Steel High Strength Bolt[J]. Heat Treatment of Metals, 2023, 48(5): 294-297.
[10] 樊俊铃, 张伟, 焦婷, 等. 飞机结构螺栓连接细节疲劳断裂失效机制与寿命分析[J]. 机械强度, 2023, 45(6): 1459-1464.
FAN J L, ZHANG W, JIAO T, et al.Failure Mechanism of Fatigue Fracture and Life Analysis for Bolted Joint of Aircraft Structure[J]. Journal of Mechanical Strength, 2023, 45(6): 1459-1464.
[11] 赵晶, 孙铭雷, 徐啸, 等. 轴向交变载荷对螺栓预紧力、变形及磨损的影响[J]. 机械设计与制造, 2021(5): 51-55.
ZHAO J, SUN M L, XU X, et al.Influence of Axial Alternating Load on Pretension, Deformation and Wear of Bolts[J]. Machinery Design & Manufacture, 2021(5): 51-55.
[12] 赵晶, 徐啸. 法兰螺栓横向微动磨损试验研究[J]. 机械强度, 2020, 42(4): 831-836.
ZHAO J, XU X.Experimental Study on Lateral Fretting Wear of Flange Bolts[J]. Journal of Mechanical Strength, 2020, 42(4): 831-836.
[13] 官永庆, 左超上, 刘永斌, 等. 备用柴油发电机组连杆螺栓断裂故障分析[J]. 内燃机与配件, 2021(6): 161-163.
GUAN Y Q, ZUO C S, LIU Y B, et al.Fault Analysis of Connecting Rod Bolt Fracture of Standby Diesel Generator Set[J]. Internal Combustion Engine & Parts, 2021(6): 161-163.
[14] 李杰, 邓云喆, 周博. 某型混凝土搅拌运输车轮胎安装螺栓失效分析[J]. 湖南工程学院学报(自然科学版), 2020, 30(4): 25-29.
LI J, DENG Y Z, ZHOU B.Failure Analysis of Tire Mounting Bolts of Concrete Mixer Truck[J]. Journal of Hunan Institute of Engineering (Natural Science Edition), 2020, 30(4): 25-29.
[15] 何竞飞, 汤涛, 汪成生. 交变横向载荷下螺栓联接自松弛有限元研究[J]. 现代制造工程, 2016(3): 1-6.
HE J F, TANG T, WANG C S.Finite Element Research on Self-Loosening Problem of Bolt Connection under the Alternating Lateral Load[J]. Modern Manufacturing Engineering, 2016(3): 1-6.
[16] ZHANG M Y, ZENG D F, LU L T, et al.Finite Element Modelling and Experimental Validation of Bolt Loosening Due to Thread Wear under Transverse Cyclic Loading[J]. Engineering Failure Analysis, 2019, 104: 341-353.
[17] 邵振威, 李有亮, 赵春雨. 基于某风电机组运输工装螺栓有限元建模方法的对比分析[J]. 机械工程师, 2021(1): 132-134.
SHAO Z W, LI Y L, ZHAO C Y.Comparative Analysis Based on the Finite Element Modeling Method of a Wind Turbine Transportation Tool Bolt[J]. Mechanical Engineer, 2021(1): 132-134.
[18] 刘飞, 张雪超, 孙常明, 等. 20Cr1Mo1VTiB钢螺栓断裂失效分析[J]. 金属热处理, 2024, 49(12): 306-311.
LIU F, ZHANG X C, SUN C M, et al.Fracture Failure Analysis of 20Cr1Mo1VTiB Steel Bolt[J]. Heat Treatment of Metals, 2024, 49(12): 306-311.
[19] 张利峰, 佟海生, 王卫东, 等. 高强螺栓断裂失效分析[J]. 材料保护, 2021, 54(10): 150-153.
ZHANG L F, TONG H S, WANG W D, et al.Analysis on Fracture Failure of High-Strength Bolt[J]. Materials Protection, 2021, 54(10): 150-153.
[20] 万朝燕, 谢素明, 李晓峰. 高强度单螺栓连接计算—VDI 2230-1: 2015标准理论解读及程序实现[M]. 北京: 机械工业出版社, 2023: 74-82.
WAN Z Y, XIE S M, LI X F.Calculation of High-Strength Single Bolt Connections—Interpretation of VDI 2230-1: 2015 Standard Theory and Program Implementation[M]. Beijing: China Machine Press, 2023: 74-82.
[21] 杜永强, 刘建华, 刘学通, 等. 偏心载荷作用下螺栓连接结构的松动行为研究[J]. 机械工程学报, 2018, 54(14): 74-81.
DU Y Q, LIU J H, LIU X T, et al.Research on Self-Loosening Behavior of Bolted Joints under Eccentric Excitation[J]. Journal of Mechanical Engineering, 2018, 54(14): 74-81.
[22] KANG J, LIU H P, FU D Y.Fatigue Life and Strength Analysis of a Main Shaft-to-Hub Bolted Connection in a Wind Turbine[J]. Energies, 2019, 12(1): 7.
[23] 刘春江, 陈贺贺, 黄超, 等. 接头螺纹磨损分析[J]. 失效分析与预防, 2020, 15(2): 123-126.
LIU C J, CHEN H H, HUANG C, et al.Wear Analysis of Joint Thread[J]. Failure Analysis and Prevention, 2020, 15(2): 123-126.
[24] ABDELRAHMAN M S, KHALIFA W, ABDU M T.Failure Analysis of Fatigue Failed M20 Class 8.8 Galvanized Steel Bolt[J]. Engineering Failure Analysis, 2023, 150: 107304.
[25] ZHENG M P, LIU Z F, YAN X, et al.Initial Losing Behavior of Pre-Tightening Force for Threaded Fastener during Repeated Tightening[J]. Engineering Failure Analysis, 2022, 134: 106021.
[26] SHEN X L, LU L T, ZENG D F.Fatigue Failure Analysis of High Strength Bolts Used for High-Speed Railway Vehicle Braking Discs[J]. Engineering Failure Analysis, 2020, 115: 104661.
基金
国家自然科学基金（52475354）; 河北省教育厅产学研专项（CXY2024054）
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