The failure (fracture) mechanism of a welded front axle tube structure made of C45E4 steel from a mini truck was analyzed. The fracture occurred on the right side of the right support frame with the fracture surface perpendicular to the tube axis. SEM examination showed that the fracture surface could be divided into three areas: intergranular area, cleavage area and dimple area. Crack initiation site of the failed front axle tube was at the front weld joint fixing the right support frame on the axle tube. The crack propagated in two opposite directions along the circumference of the tube and converged at the dimple area. Intergranular fracture was found to be in heat affected zone (HAZ). With higher magnification, fine dimples, intergranular and trans-granular fracture characteristics were observed in the crack initiation site. By metallurgical examination, Widmanstätten ferrites, which could decrease the toughness and strength of the weld joint, were observed in the columnar grains. The hardness of HAZ coarse grain area (623 VHN) was far higher than HAZ fine grain area (310 VHN) and base metal (225 VHN). As the weld process indicates, neither pre-weld nor post-weld treatment was carried out. A non-uniform temperature distribution around the weld joint could generate large thermal residual tensile stress in HAZ; thus, the material was very unstable. It could fracture for very small or even no external stress. Hydrogen atoms would be released during welding and microstructures with the highest hardness are the most susceptible of hydrogen assisted cracking. It is concluded that the fracture was caused by hydrogen assisted brittleness under the induction of weld residual stress. Post-weld aging treatment (PWAT) is recommended to release the residual stress generated during welding process. In this case, PWAT was carried out on the failed weld joint and Vickers hardness of HAZ coarse grain area, HAZ fine grain area and base metal decreased to 232 VHN, 205 VHN and 125 VHN, respectively. That indicates that the PWAT procedure could effectively soften the material and relieve residual stress.
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P. Bhagoria, S. Tom John, P. Patangia and R. Purohit, Failure analysis of the axle shaft of an automobile, Materials Today: Proceedings, 4 (4, Part D) (2017) 5398–5407.
R. Hannemann, P. Köster and M. Sander, Fatigue crack growth in wheelset axles under bending and torsional loading, International Journal of Fatigue, 118 (2019) 262–270.
C. Gesnouin, A. Hazarabedian, P. Bruzzoni, J. Ovejero-Garci´A, P. Bilmes and C. Llorente, Effect of post-weld heat treatment on the microstructure and hydrogen permeation of 13CrNiMo steels, Corrosion Science, 46 (7) (2004) 1633–1647.
E. D. Bruycker, S. Huysmans and F. Vanderlinden, Investigation of the hydrogen embrittlement susceptibility of T24 boiler tubing in the context of stress corrosion cracking of its welds, Procedia Structural Integrity, 13 (2018) 226–231.
S. Jothi, N. Winzer, T. N. Croft and S. G. R. Brown, Mesomicrostructural computational simulation of the hydrogen permeation test to calculate intergranular, grain boundary and effective diffusivities, J. of Alloys and Compounds, 645 (2015) S247–S251.
D.-G. Xie, Z.-J. Wang, J. Sun, J. Li, E. Ma and Z.-W. Shan, In situ study of the initiation of hydrogen bubbles at the aluminium metal/oxide interface, Nature Materials, 14 (2015) 899.
Y. Yan, Y. Yan, Y. He, J. Li, Y. Su and L. Qiao, Hydrogeninduced cracking mechanism of precipitation strengthened austenitic stainless steel weldment, International J. of Hydrogen Energy, 40 (5) (2015) 2404–2414.
B. R. S. da Silva, F. Salvio and D. S. d. Santos, Hydrogen induced stress cracking in UNS S32750 super duplex stainless steel tube weld joint, International J. of Hydrogen Energy, 40 (47) (2015) 17091–17101.
X. Yue and J. C. Lippold, Evaluation of heat-affected zone hydrogen-induced cracking in navy steels, Welding Journal, 92 (2013) 20S-28S.
O. Asi, Fatigue failure of a rear axle shaft of an automobile, Engineering Failure Analysis, 13 (8) (2006) 1293–1302.
N. Nishimura, K. Murase, T. Ito, T. Watanabe and R. Nowak, Ultrasonic detection of spall damage induced by low-velocity repeated impact, Central European J. of Engineering, 2 (4) (2012) 650–655.
A. H. Yaghi, T. H. Hyde, A. A. Becker and W. Sun, Finite element simulation of welded P91 steel pipe undergoing postweld heat treatment, Science & Technology of Welding & Joining, 16 (3) (2013) 232–238.
Z. Zhang, Z. Wang, Y. Jiang, H. Tan, D. Han, Y. Guo and J. Li, Effect of post-weld heat treatment on microstructure evolution and pitting corrosion behavior of UNS S31803 duplex stainless steel welds, Corrosion Science, 62 (9) (2012) 42–50.
K. Ferjutz and J. R. Davis, Fundamentals of welding: Cracking phenomena associated with welding, ASM Handbook, ASM International, 6 (1993) 229–247.
F. J. Winsor, Practice considerations for arc welding: Welding of low-alloy steels, ASM Handbook, ASM International, 6 (1993) 1625–1664.
R. M. Nunes, Atlas of fractographs: Medium-carbon steels, ASM Handbook, ASM International, 12 (1987) 470–503.
S. F. Hassan, Hydrogen induced premature failure of massive cast medium carbon steel anchor fluke, Materials & Design, 31 (2) (2010) 956–964.
J. R. Cho, B. Y. Lee, Y. H. Moon and C. J. V. Tyne, Investigation of residual stress and post weld heat treatment of multipass welds by finite element method and experiments, J. of Materials Processing Technology, 155-156 (1) (2004) 1690–1695.
G. Chakraborty, R. Rejeesh and S. K. Albert, Study on hydrogen assisted cracking susceptibility of HSLA steel by implant test, Defence Technology, 12 (6) (2016) 490–495.
R. G. Baggerly, Failure of steel castings welded to heavy truck axles, Engineering Failure Analysis, 11 (1) (2004) 115–125.
A. T. Hanzaei, S. P. H. Marashi and E. Ranjbarnodeh, The effect of hydrogen content and welding conditions on the hydrogen induced cracking of the API X70 steel weld, International J. of Hydrogen Energy, 43 (19) (2018) 9399–9407.
A. Barnoush and H. Vehoff, Recent developments in the study of hydrogen embrittlement: Hydrogen effect on dislocation nucleation, Acta Materialia, 58 (16) (2010) 5274–5285.
X. Cao, B. Rivaux, M. Jahazi, J. Cuddy and A. Birur, Effect of pre- and post-weld heat treatment on metallurgical and tensile properties of Inconel 718 alloy butt joints welded using 4 kW Nd:YAG laser, J. of Materials Science, 44 (17) (2009) 4557–4571.
S. Paddea, J. A. Francis, A. M. Paradowska, P. J. Bouchard and I. A. Shibli, Residual stress distributions in a P91 steel-pipe girth weld before and after post weld heat treatment, Materials Science and Engineering A, 534 (1) (2012) 663–672.
N. Saini, C. Pandey and M. M. Mahapatra, Effect of diffusible hydrogen content on embrittlement of P92 steel, International J. of Hydrogen Energy, 42 (27) (2017) 17328–17338.
This work was financially supported by Shandong Provincial Natural Science Foundation, China (Grant No. ZR2014YL003), the National Natural Science Foundation of China (Grant No. 11404192 and 11605106), the Key Research and Development Project of Shandong Province, China (Grant No. 2017GSF220004), the Shandong Province Special Grant for High-Level Overseas Talents and the research fund of Shandong Academy of Sciences (Grant No. 2017QN001, 2019GHPY11 and KJHZ201805), Foundation of Key Laboratory of Applied Technology of Sophisticated Analytical Instruments of Shandong Province (Grant No. 201806).
Recommended by Editor Chongdu Cho
Weimin Guo, Ph.D., Assistant Professor, works on microstructure and mechanical properties of steel and other alloys at Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China.
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Guo, W., Ding, N., Xu, N. et al. Fracture analysis of a welded front axle tube structure from a mini-truck. J Mech Sci Technol 34, 109–116 (2020) doi:10.1007/s12206-019-1210-4
- C45E4 steel
- Residual stress
- Hydrogen embrittlement