正在众多钢管中，方管算是性能比较好的一类了。下面我们一起来了解一下方管的一种制作工艺吧。方管冷拔成型实弯的优点是反弹小，成型准确，而且只要辊型准确，内角成型的R比较准确。 空弯的优点是可以在无法进行实弯时进行边长的弯折，比如方矩管的上边/侧边同步弯折和精整。空弯还可以弯折R<0.2t的内角而不致管壁发生断裂。

Among many steel pipes, square pipes are of better performance. Next, let's learn about a kind of manufacturing technology of square tube. The advantages of square tube cold-drawing forming solid bending are small rebound, accurate forming, and as long as the roll shape is accurate, the R of inner corner forming is more accurate. The advantage of empty bending is that it can bend the side length when it is impossible to bend, such as synchronous bending and finishing of the top/side of square tube. Empty bending can also bend the inner angle of R < 0.2T without breaking the pipe wall.

实弯的缺点是有拉伸/减薄效应。第一，实弯会使弯折处产生拉伸，拉伸效应使弯折线纵向的长度缩短; 第二，实弯弯折处金属会因拉伸而变薄。 空弯的缺点是在上边/侧边同步空弯时，由于上辊和下辊同时产生压力，成型力容易超越临界点，造成边部失稳内凹，并且也会影响到机组稳定运行和成型质量。这也是方矩管和圆管空弯成型时不同的特点。

The disadvantage of solid bending is its stretching/thinning effect. Firstly, the real bending will make the bending place stretch, and the stretching effect will shorten the longitudinal length of the bending line; secondly, the metal in the real bending place will become thinner due to stretching. The disadvantage of blank bending is that when upper/side synchronous blank bending occurs, the forming force easily exceeds the critical point due to the simultaneous pressure of upper and lower rolls, resulting in the instability of the edge concave, and also affecting the stable operation and forming quality of the unit. This is also the different characteristics of square tube and circular tube in air bending forming.

综上所述，方管的冷拔工艺有优点也有缺点，但没有什么东西是完美的，每个物品都各有各的优点。想要了解更多资讯请随时关注我们的网站，我们会有专业的客服为您服务,感谢各位的支持。

To sum up, the cold drawing process of square tubes has both advantages and disadvantages, but nothing is perfect, each item has its own advantages. For more information, please keep an eye on our website. We will have professional customer service for you. Thank you for your support.