菱形孔型

This approach is base on the following idea:under not effect to the deformation of rectangular pipe,to change right angle to obtuse angle which is variant as some regular,make plain-barreled roll pass receive vertical roll shape pipe blank,and then let pipe blank entering into vertical roll pass.With continuous deformation, the difference between diagonal line of rhombus pass will be reduced to zero,finally changed into a square.

该方法的基本思路是：在不影响方矩形管变形的前提下，通过将孔型顶角由直角改为按一定规律变化的钝角，让呈卧菱形状的平辊孔型接纳呈立菱形状的管坯，接着让卧菱形状的管坯进入立菱形状的立辊孔型，随着变形的继续，逐渐缩小菱形孔型对角线之差直至为零，成为正方形。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。