一、理论基础所有钢材在室温下的变形抗力K_f随着用对数表示的变形比φ的增大而增加(图1),这种所谓冷态变形抗力依钢材品种不同而可以很快达到很大的数值,以致在冷态下几乎不可能成形,或者仅能在极小范围内进行。倘若在成形前将材料加热,则其初始抗力随着预热温度θ的升高而降低。此外,在提高变形比时,抗力增加并不显著。 First, the theoretical basis All steel deformation resistance K_f at room temperature with logarithmic deformation than the increase of φ increases (Figure 1), the so-called cold deformation resistance according to the different varieties of steel can reach very large So that it is almost impossible to form in a cold state or only to a very small extent. If the material is heated prior to forming, its initial resistance decreases with increasing preheat temperature θ. In addition, the increase in deformation ratio, the increase in resistance is not significant.