Analysis and Modeling of Flow Stress of 40Cr Steel
LI Xiong1, ZHANG Hong-bing2, RUAN Xue-yu1, LUO Zhong-hua1, ZHANG Yan3
1. Department of Plasticity Technology, Shanghai Jiao Tong University, Shanghai, 200030, China; 2. Department of Materials Engineering, Shanghai Institute of Technology, Shanghai, 200235, China; 3. StateKey Laboratory for Advanced Metals and Materials, University ofScience & Technology Beijing, Beijing, 100083, China
Abstract：The flow stresses at various deformation conditions were studied. The results show that flow stress decreases with deformation temperature increasing, and increases with strain rate increasing. Based on Ludwik-Hollomon model, an improved model suiting for hot and warm working was discussed. A good result was got when modeling flow stress of 40Cr steel in the improved model. Hardening exponent n is insensitive to deformation temperature. At low strain rate, n value is hardly changed; when up to a high strain rate, n jumps to a high value. By simplifying some parameters, peak stress can be predicted. The average relative error and the mean square root between predicted and experimental flow stresses are 7.7% and 17.59MPa, respectively.
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