The Influence Of Roller's Position On The Formation Quality Of Pipes With High Ratio Of Diameter To Thickness

Cage roll-forming is an advanced technique to manufacture High Frequency Welding(HFW)round pipes.The majority of domestic advanced cage roll-forming mills are introduced from foreign countries,but the information of the equipment design and development technology isn't provided by the supplier.The rollers' position parameter is adjusuted by experience to eliminate defects during the pilot production,especially the manufacture of pipes with high ratio of diameter to thickness.In this thesis,the numerical simulation technology is took to study the influence of rollers' position on the formation quality basing on the HFW 660 cage roll forming mill manufactures pipes with high ratio of diameter to thickness.The manufacture of ?508mm pipe with 6.2mm in thickness made of X60 was regared as example.ABAQUS was used to simulate the whole cage roll-forming process of HFW round pipes.The accuracy of the simulation was verified by comparing with production data.The results showed that:if the deformation was non-uniformed during the cage roll-forming process,a lot of deformation would occur at the No.1 fin-pass stand.The biggest value of longitudinal strain,stress and effective plastic strain could be found at the strip edge,which would lead to defects easily.Then,the roller's position are adjusted to get better technological parameters.The forming bottom line and opening value were used to represent all the rollers' position.The result showed that: the formation quality of strip edge will be influenced if the downhill height wasn't appropriate;As a prerequisite to ensure the good shaping of strip edge.The amount of deformation could be improved by reducing the opening value during the cage roll-forming process.This thesis was aimed to provide reference to eliminate defects and optimize process.