Residual Stress Analysis Of Spiral-Three-wire Submerged Arc Welded Pipe

Large diameter and high strength is the main development direction of pipeline,the biggest problem about the welded pipe's manufacturing which with the thick wall and large diameter is to control the residual stress.Researching residual stress of the spiral welded pipe can analyze the distribution of the welding residual stress effectively;evaluate the welding quality of the spiral welded pipe.At the same time,it also can provide theoretical basis to reduce and eliminate welding residual stress.Firstly,using ABAQUS finite element simulation software as the platform,established the finite element analysis model which was used for the forming process of the large diameter spiral welded pipe X80,picked for the preferable molding parameters with a diameter of 1219 mm,wall thickness of 18.4 mm spiral welded(molding angle 61°,the amount of depression7.5 mm).The article concluded that the stress distribution in the molding process under the most preferred molding parameters and referring to the internal tube in each direction(circumferential,radial and axial).Secondly,this article established a model with a diameter of 1219 mm,wall thickness of18.4 mm large diameter of spiral welded pipe with three-wire submerged arc welding residual stress.The simulation results obtained three-wire submerged arc welding spiral welded pipe temperature and stress field and the simulation results were the same with the ideal phase consistent.Through measuring the water pressure and the residual stress after corrosion protection of a diameter of 1219 mm,wall thickness of 22.0 mm spiral submerged arc welded pipe three wire welding by the method of the blind hole,this article obtained that the effect of getting the water pressure and the corrosion protection to spiral pipe welding residual stresses.Finally,comparing with a diameter 1219 mm,but different thickness(18.4 mm and 25.4mm)of spiral pipe welding residual stress,the article concluded the relationship between the size of the welding residual stress and the wall thickness of the spiral welded pipe.There are many factors affect the welding residual stress(welding technology,pipe geometry,welding materials).Among then,welding heat input has a great effect on the spiral pipe welding residual stress.By simulating the residual stress of a diameter 1219 mm,wall thickness of 25.4mm spiral welded pipe in different welding heat input,the article came up with the influence rule of welding heat input on welding residual stress,optimized three-wire submerged arc welding parameters.