The lower heat-treating temperature of the case results from the fact that hypereutectoid steels are normally austenitized for hardening just above the lower critical point.

由于恰好高于低临界温度通常使过共析钢奥氏体化而硬化，所以对外层采用较低的热处理温度。

youdao

I have here that same ladder, and now what I will do is I will set the angle alpha not exactly at the critical point but a little lower, so that when I let it go, we'll all see that it will slide.

这是一个梯子，现在我要,使得角度α,不是恰等于临界点,而是略小一些，所以当我放手，我们会看到它下滑。

youdao

The lower limit of temperature at which this occurs is known as the softening point or critical temperature.

呈现这一性质的温度下限称为软化点或临界温度。

youdao