Many large diameter square tube defects are caused by the perforation in square and rectangular tube, so the mass production of large diameter power process is the key process square tube.
Perforation main difficulty lies in the low alloy high performance perforation, when necessary in order to ensure the quality of the deformation parameters of rational choice perforation.
Large diameter square tube small amount of compression will cause instability perforation process, so critical compression child’s head should be the first compression generally set at about seven percent, otherwise it will not bite, even before the card is added or moved. Head in front of the increasing amount of compression will form inside the cavity and Chen Sheng defects so if you want to overcome the problem, then the tube also centering, centering depth and space to compare based on other steels. So is the way of the heating system on the heating temperature and quality requirements. The quality of the heating depends largely on the heating operation and the heating system. Relatively small value of the coefficient is generally favorable oval improve the quality of the hair and can limit the cross tube deformation. But nor too small oval coefficient, which will cause difficulties rolling rotation, and even lead to the guides wear, likely to cause defects on the surface.
Tie the boat when the large diameter square tube should generally check the wear guides, once discovered, immediately replaced, should control the degree of the ellipse inside the 1.07-1.08 range. After the normal process steps as well as the impact of large diameter square tube heating tube key processes, which affect the quality of the finished product is also very large.