Discussion on Formation Regulating of SSAW Pipe with Low Structual Stress

Described in the article is the principle of producing the SSAW pipe with the low structural stress forming process with the externally-controlled forming mechanism. Using the said forming mechanism the tube OD is ensured, and the tube wall residual stress reduced by means of the pre-bending unit and the sizing alignment unit, the three-roll over-deformation plate bending process as well as taking advantage of the resistance as imposed by the sizing bush and the welding support roll. The said regulation via the process of three-roll over-deformation plate bending plus slight resistance control is capable of bringing about consistent manufacturing process of the steel tube with low structural stress (or even negative spring-back). Also described is some key issues concerning the said formation regulating.