Theory Analysis And Experimental Research On Longitudinal JCO Forming Process

JCO welded pipe forming method is an important method of the production of longitudinal welded pipe. JCO forming process is a very complex deformation process involving a long line of technology, many material parameters, process parameters and mold structure parameters, the mutual influence of various parameters have complex relationships, and all relate with the final forming quality of the welded pipe. Therefore, this paper will do some systematic theoretical analysis of JCO forming process of longitudinal welded pipe, researching bending forming mechanism of straight tube, to guide practice.This article firstly introduces the characteristics of longitudinal welded pipe, molding process method and the current of domestic and international situation. And then starting with the theory of plastic deformation of plates, the thesis describes the bending process of open-seam pipes theoretically by applying the mathematical analysis method on the basis of the reasonable presumption and simplification of bending process. Analyze the pure bending behaviors of hardening exponent model. Introduces the importance of pre-bending process of straight seam welded pipe and pre-bending process, analyzes the main pre-bending process parameters, such as pre-bending roll angle, pre-bending length and pre-bending force and so on, derives formula of parameters. Through the gradual multi steps of moulded forming process is analyzed theoretically, the mathematical model of the asymmetry and symmetry moulded forming is established respectively,mainly reveals the internal relationship among the bending force, bending radius and angle during the process and derives a series of analytic formula. Using similarity theory, scientifically designed experimental program, acquisition experimental data, comparing with the experimental data and theoretical, and analyzes the error causes, verify the theoretical derivation of rationality.Through this topic research, will guide the adjustment of JCO molding process of longitudinal welded pipe, properly predict pipeline steel sheet bending angle, in order to reduce the labor intensity of staff, to improve product quality and production efficiency.