(東北大學(xué)金屬壓力加工系， 沈陽(yáng) 110006)
摘 要: 用結(jié)晶器壁內(nèi)表面光潔度的假設(shè)， 提出了處理結(jié)晶器、鑄件有間隙接觸問(wèn)題的方法， 避免了測(cè)定鑄件表面溫度或結(jié)晶器熱流密度這一難題， 建立了鑄拉時(shí)的溫度場(chǎng)， 得到了鑄件的溫度分布、 液穴形狀及結(jié)晶器與鑄件間間隙值與工藝參數(shù)的關(guān)系。同時(shí)，提出了一種新的摩擦計(jì)算模型，并求得了摩擦應(yīng)力與間隙值、表面光潔度和鑄件表面剪切強(qiáng)度之間的關(guān)系。 然后根據(jù)限制鑄拉速度的主要缺陷，即凝固殼斷裂和冷隔， 通過(guò)計(jì)算鑄件截面承受的摩擦力、熱應(yīng)力和液穴形狀，得到了鑄拉工藝的極限速度， 計(jì)算值與實(shí)測(cè)值吻合。
關(guān)鍵字: 關(guān)鍵詞: 平均粗糙度 間隙 液穴 剪切變形 熱應(yīng)力
（Department of Metal Forming, Northeastern University,Shenyang 110006, P. R. China）
Abstract:By the assumption of the roughness about the inner of crystallizer, a way was proposed to deal with the contacting boundary between crystallizer and ingot, which resulted in avoiding measuring the surface temperature of ingot or the heat flow intensity of crystallizer; the temperature field in the cast-drawing process was established, which included the temperature distribution, the shape of liquid cave, and the gap size between crystallizer and ingot along vertical direction under different technological conditions. Also, a new model was proposed to calculate the friction between crystallizer and ingot, and the relation of frictional stress between the gap size, the roughness and the surface temperature of ingot was obtained. Then, the limit speeds of cast-drawing were calculated according to the main technical defects, i.e. the cold shut and the solid break, the calculation value corresponded with the measured results.
Key words: mean roughness gap liquid cave shear deformation
thermal stress
