Content of FAILURE ANALYSIS in our journal

Published in last 1 year |  In last 2 years |  In last 3 years |  All Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Fracture cause analysis of one tower bolt Zhang Demei, Liang Xiaodong, Zhang Yan Heat Treatment of Metals    2025, 50 (2): 312-315.   doi:10.13251/j.issn.0254-6051.2025.02.050 Abstract （27）      PDF （2621KB）（14）       Knowledge map    One tower bolt used in one wind-power station was fractured. The fracture cause of the failed bolt was analyzed by means of metallographic examination, SEM-EDS analysis, chemical composition testing and mechanical property testing. The results show that chemical composition and mechanical properties all meet the requirements of national standard. There is no abnormality for the microstructure. But the R value at the connection between the head of the fractured bolt and the screw is too small. The depth of Zn-Ni plating near the crack source is deeper than other edges, which indicates that during quenching and tempering treatment, cracks are generated at the intersection of the bolt head and the screw under the action of quenching stress. When in use, under the action of force, cracks continue to propagate, ultimately leading to fatigue fracture. Reference | Related Articles | Metrics Select Common failure problems and corresponding strategies for walking wheels of coal mining machines He Xiao, Xu Hongxiang, Shi Lubing, Chen Shengchao, Li Ziyan, Rong Zeyu, Li Fuli Heat Treatment of Metals    2025, 50 (2): 304-311.   doi:10.13251/j.issn.0254-6051.2025.02.049 Abstract （19）      PDF （2536KB）（7）       Knowledge map    Walking wheel, as the actuator of the walking device of the coal mining machine, often suffers from tooth breakage accidents due to the effect of strong impact loads. This seriously affects the working efficiency and poses a threat to the personal safety of the operators. Thus firstly, the failure modes of the walking wheel, such as wear, tooth breakage, spalling and plastic deformation of the tooth surface were expounded. Subsequently, for the tooth breakage failure, the coping strategies were summarized, including optimizing the product design, rationally selecting materials, increasing the gear modulus, installing protective devices and optimizing the heat treatment process. Finally, the suggestion of combining traditional carburizing and quenching processes with Q-P-T processes was proposed for heat treatment of walking wheel to improve its strength and toughness. Reference | Related Articles | Metrics