无模拉伸温度场的实验研究

Experimental Study on Temperature Field in Dieless Drawing

在自制的无模拉伸机上,研究了无模拉伸温度场的形态及其影响因素,分析了无模拉伸温度场的变化规律,提出以被拉伸线材的最高温度、内部与表面层的温差及变形区轴向温度梯度作为反映无模拉伸温度场形态的特征参数。实验和分析表明:加热线圈和冷却装置的移动速度的增大,使拉伸温度下降,变形区的轴向温度梯度减小。而变形程度的增大,加热线圈与冷却喷嘴间距的减小,使无模拉伸温度下降,增大变形区的轴向温度梯度。在高频感应加热条件下,导磁性材料的拉伸温度受加热线圈和冷却装置的移动速度影响小。

Features and their influencing factors were investigated on a self--madedrawbench for the temperature field in dieless drawing, with the. variation oftemperature field discussed. It is proposed that the temperature field in dielessdrawing should be characterized by the maximum temperature of wire drawn,temperature difference between the inner and surface layer of the wire andthe axial temperature gradient in deformation zone. The results show thatboth tbe drawing temperature and the axial temperature gradient in deforma-tion zone will decrease when increasing the speeds of moving heating coil andcooling deveces. But, with the deforma tion increased and the distance fromheationg coil to cooling nozzle decreased, the drawing temperature lowersand the axial temperature gradient rises. In case of high--frequency inductionheating, the speeds of moving heating coil and cooling devices are of smallinfluence on the drawing temperature of megnetized materials