外文翻譯--軋制過程中的熱傳遞外文-資料下載頁(yè)
2025-08-09 06:37本頁(yè)面
【正文】 not show an explicit dependence of the temperature loss on the flow rate and pressure of cooling water. The flow rate and pressure, however, may substantially affect the thermal conductivity k of the surface layer that separates the body of workpiece from cooling water. Indeed, the surface layer consists of scale and boiled water, which work as a thermal barrier. This barrier will be weakened to a greater degree with increase of both the flow rate and pressure of cooling water. LOSS DUE TO CONDUCTION TO WORK ROLLSTemperature loss due to heat conduction to the work roll can be calculated if it is assumed that two bodies of uniform unitial temperature T and Tr are pressed against each other and that, at the interface, considered to be plane, there is contact resistance formed by oxide layer.Under these assumptions, the process can be described with the following heat balance equations. According to Schack, the total amount of heat passing through two outer surfaces of the plate may be calculated from the formula Where Ac——contact area between rolled material and work rolls，m2； k——thermal conductivity of the workpiece oxide layer，W/（mK）； ——heat gained by work roll or heat lost by body due to thermal conduction，J； Tr——roll temperature，K； a——thermal diffusivity of workpiece，m2/s。The amount of heat lost by the rolled metal in the roll bite is given by: Where ——temperature loss by rolled material due to contact with work rolls，K。From the heat balance condition =，Eqs 115 and 116, and also taking into account that and where R—work roll radius, m. ha—average workpiece thickness, m.we obtain the following formula for the temperature loss due to conduction to work rolls:= Equation for temperature loss due to contact with rolls which have been obtained by reducing some of the known equations to a patible form are summarized in the Table and are plotted in . The substantial discrepancies in temperature losses calculated from different equations are due mainly to the uncertainty in estimating thermal conductivity k which depends on the contact resistance resistance of the oxide layer between the roll and the rolled material.外文翻譯資料（）班 級(jí)： 姓 名：高鑫指導(dǎo)老師：王德
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