Homogeneity of microstructure and Vickers hardness in cold closed-die forged spur-bevel gear of 20CrMnTi alloy
来源期刊：中南大学学报(英文版)2015年第5期
论文作者：DONG Li-ying LAN Jian ZHUANG Wu-hao
文章页码：1595 - 1605
Key words：cold closed-die forging; 20CrMnTi alloy; microstructure; Vickers hardness
Abstract: Cold closed-die forging is a suitable process to produce spur-bevel gears due to its advantages, such as saving materials and time, reducing costs, increasing die life and improving the quality of the product. The homogeneity of microstructure of cold closed-die forged gears can highly affect their service performance. the homogeneity of microstructure and Vickers hardness in cold closed-die forged gear of 20CrMnTi alloy is comprehensively studied by using optical microscopy and Vickers hardness tester. The results show that the distribution homogeneity of the aspect ratio of grain and Vickers hardness is the same. In the circumferential direction of the gear tooth, the distribution of the aspect ratio of grain and Vickers hardness is inhomogeneous and they gradually decrease from the surface to the center of the tooth. In the radial direction, the distribution of the aspect ratio of grain and Vickers hardness is inhomogeneous on the surface of the gear tooth; while it is relatively homogeneous in the center of the gear tooth. In the axial direction of the gear tooth, the distribution of the aspect ratio of grain and Vickers hardness is relatively homogeneous from the small-end to the large-end of the gear tooth.
DONG Li-ying(董丽颖)1, LAN Jian(兰箭)1, 2, ZHUANG Wu-hao(庄武豪)1
(1. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China;
2. School of Automotive Engineering, Hubei Key Laboratory of Advanced Technology of Automotive Parts,
Wuhan University of Technology, Wuhan 430070, China)
Abstract:Cold closed-die forging is a suitable process to produce spur-bevel gears due to its advantages, such as saving materials and time, reducing costs, increasing die life and improving the quality of the product. The homogeneity of microstructure of cold closed-die forged gears can highly affect their service performance. the homogeneity of microstructure and Vickers hardness in cold closed-die forged gear of 20CrMnTi alloy is comprehensively studied by using optical microscopy and Vickers hardness tester. The results show that the distribution homogeneity of the aspect ratio of grain and Vickers hardness is the same. In the circumferential direction of the gear tooth, the distribution of the aspect ratio of grain and Vickers hardness is inhomogeneous and they gradually decrease from the surface to the center of the tooth. In the radial direction, the distribution of the aspect ratio of grain and Vickers hardness is inhomogeneous on the surface of the gear tooth; while it is relatively homogeneous in the center of the gear tooth. In the axial direction of the gear tooth, the distribution of the aspect ratio of grain and Vickers hardness is relatively homogeneous from the small-end to the large-end of the gear tooth.
Key words:cold closed-die forging; 20CrMnTi alloy; microstructure; Vickers hardness
