Based On The Finite Element Analysis Software Sump Pumps Welding Applications

Sump pumps are ideal equipments for pressure fed pneumatic conveying the powdery materials such as cement,slag,fly ash,food,chemicals. Most sump pumps can run at high temperature and pressure. Therefore,the welded joints of the sump pump must have high strength and high wear resistance,and must have sufficient high impact toughness and high heat resistance. And it must have no defect such as crack-free,end fusion etc. In this paper,we researched sump pump that is one of the main low-pressure container products of Zhejiang Feida Environmental Science & Technology Co,Ltd. It is the key component of the pneumatic conveyor equipment. The housing base metal is 15CrMoR steel. Therefore,what we must solve is how to solve the problem of 15CrMoR steel welding crack and to acquire high quality welding joint with high strength,plasticity and flexibility.For 15CrMoR steel,we calculated its the welding crack susceptibility and analyzed its mechanism of crack sensitive and feasibility analysis of welding process. In this paper,its main study contents include to a combination of the MAG welding backing,filling,capping and submerged covering up with the actual production. A dynamic imitation is made about sump pumps welding temperature field and stress field to use ANSYS system. We established a finite element analytical model on ANSYS soft system. A scientific analysis is used to measure changes of weld residual stress for the distribution of welding temperature field at different times. It supply a scientific base on multi-pass welding of 16mm medium and heavy plate.In the technical design of sump pumps welding,we adopt different preheating temperature,welding current,welding speed and welding heat input. We did X-ray radiographic inspection for welding line and the mechanical test was also presented. It reachesⅡgrade standard of JB4730-2005 Nondestructive Testing of Pressure Equipment. The appearance of welding reaches I grade standard of GB50236-98 of Code for Construction and Acceptance of Field Equipment,Industrial Pipe Welding Engineering. We analyzed its microstructure,microstructure of welding line acid beat affected zone are pole type ferrite,barite and martensite. We optimized the dependable and effective welding technology after welding. Results studied are showed: When 15CrMoR steel welds in welding filling material H13CrMoA,the preheating temperature 150-180℃,welding voltage 22±1V,welding current 130-170A,postheating 250℃,preservation 1h,normalizing temperature 900℃,preservation 1h in furnace cooling,beat treatment temperature 680±100℃,beat preservation lh. Its joint strength obtains 560Mpa and impact of beat effect zone arrives at 79J.It absolutely accords with demand of pressure which we research in the project.We find by the research that the heat input major affects the microstructure and performances of joint. The more are the thermal input,the serious are brittleness of beat affected zone. In the many welds,we can improve phenomenon of brittleness and soften of joint and meet demand of conduct by adjusting thermal input and controlling cooling.Now,welding technique of 15CrDIoR steel has been applied to welding production. The quality for welding have met demand of state standard.