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一、前言中温挤压工艺对坯料的加热,是温挤压工艺过程的主要工序之一,也是中温挤压工艺的一个特殊要求。加热能使金属的塑性增高,从而减低其变形抗力;但是加热温度过高,坯料容易形成较厚的氧化皮,降低挤压件的精度与光洁度。加热温度超过材料的 Ac_1点会使坯料产生相变,导致后工序的许多不利因素,减低模具的使用寿命等。加热温度过低,坯料强度高,变形抗力大,要求设备容量大。因此,中温挤压的加热温度的高、低是相互矛盾的问题。所以对中温挤压工艺确定较理想的温度区间和准确地控制温度是一个很重要的问题。
I. INTRODUCTION The warm extrusion process is one of the main processes of warm extrusion process and also a special requirement of medium temperature extrusion process. Heating can increase the plasticity of the metal, thereby reducing the deformation resistance; but the heating temperature is too high, the billet easily form a thick oxide scale, reducing the precision and finish of the extrusion. The heating temperature exceeds the material Ac_1 point will make the blank phase change, resulting in many unfavorable factors after the process, reducing the service life of the mold. Heating temperature is too low, billet strength, deformation resistance, equipment capacity requirements. Therefore, medium temperature extrusion heating temperature is high and low is a contradictory issue. Therefore, it is a very important issue to determine the ideal temperature range and accurately control the temperature in the medium temperature extrusion process.