The improvement of economy promotes the continuous progress of the construction industry. We all know that in the construction industry, the types of steel are different according to different needs, and the square tube is no exception. Maybe there are some friends who don't know much about Fangguan. Next, let's talk about how Fangguan came into being
1、 Solid bend
In the actual bending process, the inner and outer rollers and the inner and outer walls of the tube blank are compacted in both directions.
(1)实弯的长处是弹起小，成型精 确，并且只需辊型精 确，内角成型的R比拟精 确。
(1) The advantages of real bending are small bounce, precise forming, precise roll shape, and precise r-analogy of internal angle forming.
(2) The imperfection of real bending is tensile / thinning effect. The real bending will make the bending place stretch, and the stretching effect will make the length of the bending line lengthen; The metal at the real bend will be thinned by stretching.
2、 Empty bend
Empty bending is the bending moment formed by the one-way contact between the outer roll and the outer wall of the tube blank, which makes the strip bend. Empty bending will make the bending line shrink, the contraction effect will make the bending line expand longitudinally, and the non-metal deposition at the bending place will become thicker. This is the contraction / thickening effect of empty bending.
The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the top / side of rectangular tube. The outer corner with R < 0.2T can be bent without breaking the tube wall.