中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 28 No. 5 May 2018 |
（1. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China; 2. Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China）
Abstract:According to inverse heat transfer theory, the evolutions of synthetic surface heat transfer coefficient (SSHTC) of the quenching surface of 7B50 alloy during water-spray quenching were simulated by the ProCAST software based on accurate cooling curves measured by the modified Jominy specimen and temperature-dependent thermo-physical properties of 7B50 alloy calculated using the JMatPro software. Results show that the average cooling rate at 6 mm from the quenching surface and 420-230 °C (quench sensitive temperature range) is 45.78 °C/s. The peak-value of the SSHTC is 69 kW/(m2×K) obtained at spray quenching for 0.4 s and the corresponding temperature of the quenching surface is 160 °C. In the initial stage of spray quenching, the phenomenon called “temperature plateau” appears on the cooling curve of the quenching surface. The temperature range of this plateau is 160-170 °C with the duration about 3 s. During the temperature plateau, heat transfer mechanism of the quenching surface transforms from nucleate boiling regime to single-phase convective regime.
Key words: 7B50 aluminum alloy; water-spray quenching; inverse heat transfer theory; synthetic surface heat transfer coefficient; cooling curve
