Experimental study of heat-transfer coefficient of Al-Zn-Mg-Cu ultra-thick hot plate during multi-stage quenching  

作　　者：FAN ShiTong DENG YunLai ZHANG Yong HUANG XinYue WU PengFei FAN ShiTong;DENG YunLai;ZHANG Yong;HUANG XinYue;WU PengFei(School of Materials Science and Engineering, Central South University; Changsha 410083, China;State Key Laboratory of High Performance and Complex Manufacturing, Central South University, Changsha 410083, China)

机构地区：[1]School of Materials Science and Engineering, Central South University [2]Changsha 410083, Chin [3]2 State Key Laboratory of High Performance and Complex Manufacturing, Central South University, Changsha 410083, China

出　　处：《Science China(Technological Sciences)》2018年第6期916-922,共7页中国科学（技术科学英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2012CB619500);the Major State Research Program of China(Grant No.2016YFB0300901);the National Natural Science Foundation of China(Grant No.51375503);the BaGui Scholars Program of China’s Guangxi Zhuang Autonomous Region(Grant No.2013A017)

摘　　要：Experiments were conducted to investigate the cooling manner of an ultra-thick hot aluminum alloy plate during multistage quenching. Cooling curves and heat flux curves of different rapid quenching flux varied from 23 to 40 L min-1 and were analyzed in detail. In this investigation, cooling process was divided into the following four steps： （Ⅰ） starting step, （Ⅱ） rapid cooling step, （Ⅲ） slow cooling step, and （Ⅳ） stopping step. Based on the curves, the calculation method for surface transfer coefficient was provided, and the effects of coefficient on surface temperature and quenching flux were discussed. Results showed that the transfer coefficient disagreed with heat flux and that it is a nonlinear function of surface temperature. The highest coefficient was observed not in the rapid cooling step with the largest heat flux but in the slow cooling step with lower heat flux. The coefficient increased with surface temperature ranging from 480 to 150℃, and a coefficient peak appeared in the temperature range of 150- 100℃. The coefficient also increased with quenching flux. Finally, a simulation was performed using the finite element method to verify the reliability of the coefficient results, which showed good agreement with the measurement values.

关 键 词：heat transfer coefficient multi-stage quenching aluminum alloy PLATE finite element method 

分 类 号：TG156.3[金属学及工艺—热处理]