摘要
接触换热系数直接决定金属热加工过程的温度分布,进而影响零件的微观组织及使役性能。本文采用自主开发的稳态接触换热设备和测量系统,系统研究了纯铜及H62黄铜与H13模具钢在接触面温度为200~600℃、压力为1.56~12.56 MPa下的接触换热行为。结果表明,载荷加载的历程对接触换热系数有较大影响,相比于从低载荷加载到目标压力时,从高载荷卸载到同一目标压力测得的接触换热系数更高;在相同加载历程下,接触换热系数随着界面温差的升高而增加,且界面温度高于400℃时接触换热系数增速变快;接触换热系数与压力呈幂指数关系增长,随着压力的增大,接触换热系数增长逐渐变得缓慢;在相同条件下,黄铜/H13传热时的温度梯度更大,导致黄铜/H13的接触换热系数更大。
The contact heat transfer coefficient directly determines the temperature distribution of the metal hot working process,which further affects the microstructure and service performance of the parts.Using the self-developed steady-state contact heat transfer equipment and measurement system,the contact heat transfer behavior of pure copper,H62 brass and H13 die steel at the contact surface temperature of 200-600℃and the pressure range of 1.56-12.56 MPa was systematically studied.The results show that the loading history has a great influence on the contact heat transfer coefficient.Compared with loading from a low load to a target pressure,the contact heat transfer coefficient measured from a high load unloading to the same target pressure is higher.Under the same loading history,the contact heat transfer coefficient increases with the increase of the interface temperature difference,and the contact heat transfer coefficient increases rapidly when the interface temperature is higher than 400℃;the contact heat transfer coefficient increases exponentially with the pressure,and the increase of the contact heat transfer coefficient gradually becomes slower as the pressure increases;under the same conditions,the temperature gradient during heat transfer of brass/H13 is larger,resulting in a larger contact heat transfer coefficient of brass/H13.
作者
国林磊
张驰
张立文
陈仁朝
运新兵
邵志文
GUO Linlei;ZHANG Chi;ZHANG Liwen;CHEN Renchao;YUN Xinbing;SHAO Zhiwen(School of Material Science and Engineering,Dalian University of Technology,Dalian 116028,China;Engineering Research Center of Continuous Extrusion,Ministry of Education,Dalian Jiaotong University,Dalian 116028,China;Ningbo Branch,Ordnance Science Institute of China,Ningbo 315103,China)
出处
《热加工工艺》
北大核心
2024年第15期22-26,共5页
Hot Working Technology
基金
国家重点研发计划资助项目(2019YFA0705300)。
关键词
铜
黄铜
热加工工艺
接触换热系数
界面温差
压力
copper
brass
hot working technology
interfacial heat transfer coefficient
interface temperature difference
pressure
