摘要
通过喷射淬火试验,研究了在高温铝合金表面进行水射流淬火、喷雾淬火和高速空气淬火的热交换过程,并对这3种在线淬火界面的热流密度(q)和传热系数(h)进行了反分析求解,重点探究了试样表面介质流量密度(q_(s))对界面热交换率的影响规律及其机理。结果表明,随q_(s)增大,喷射淬火界面热交换率先增大后减小,即存在一个临界q_(s),此时临界热流密度(q_(c))取得最大值。当q_(s)小于其临界值时,喷射淬火界面热交换率随q_(s)增大而增大;当q_(s)大于临界值时,随q_(s)继续增大,喷射淬火界面热交换率反而减小。喷雾淬火的单位体积冷却介质最大吸热量(Q_(max))最高,且淬火介质相同时,Q_(max)随q_(s)增大而减小。增大q_(s)对提高喷水淬火表面的热交换率效果最好。
The heat exchange processes of water jet quenching,spray quenching and high speed air quenching on high temperature aluminum alloy surface were studied by jet quenching test.The heat flux(q)and heat transfer coefficient(h)of the three kinds of on-line quenching interface were calculated by back analysis method,and the influence law and mechanism of the medium flux density(q_(s))on the interface heat exchange rate were mainly investigated.The results show that with the increase of q_(s),the heat exchange rate of quenching interface increases first and then decreases.There is a critical q_(s),when the critical heat current density(q_(c))reaches the maximum value.When q_(s) is less than its critical value,the interfacial heat exchange rate increases with the increase of q_(s).When q_(s) is greater than the critical value,the interfacial heat exchange rate decreases with the increase of q_(s).The maximum heat absorption(Q_(max))of the unit volume cooling medium in spray quenching is the highest,and when the quenching medium is the same,the Q_(max) decreases with the increase of q_(s).Increasing q_(s) has the best effect on improving the heat exchange rate of water jet quenching surface.
作者
徐戎
李落星
Xu Rong;Li Luoxing(College of Mechanical Engineering,Hunan University of Arts and Science,Changde Hunan 415000,China;College of Mechanical and Vehicle Engineering,Hunan University,Changsha Hunan 410082,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第2期243-249,共7页
Heat Treatment of Metals
基金
湖南省教育厅科研项目(20B406)
湖南省自然科学基金(2018JJ2274)
湖南省高等学校“双一流”建设项目(湘教通[2018]469)
湖南省高等学校创新团队项目(湘教通[2019]379)。
关键词
喷射淬火
在线淬火
界面热交换率
界面热流密度
介质流量密度
jet quenching
on-line quenching
interface heat exchange rate
interfacial heat flux
medium flow density
