Repair of 20CrMnSiVaL steel pumping units with the use of welding technologies

摘要

20CrMnSiVaL low-alloy cast steel is widely used for tanks, machines and devices (pumps, compressors, hydraulic boxes and other) in the oil and gas industry. A large amount of such equipment operates under conditions of high pressure, corrosive effect of the working environment, a large temperature difference, mechanical loading due to moving parts.During its operation the elements of oil and gas are eroded due to temperature and power loads, corrosion, and other factors. Most constructive elements of gas and oil equipment are repaired by welding. A highly concentrated heat source and deformation capacity are the cause of residual stresses. They affect the performance and accuracy of manufacturing elements.One of the main problems concerning the improvement of the quality of machines is the enhancement of housing repair technology. The housings are made of cast steel using electric arc welding.In this work we employed the finite element method in the program ANSYS. We performed an analysis of stress-strain state in the model of the welded joint simulating the machine body. We considered and implemented the technology of repair by welding and different types of treatment. We conducted a comparative study of mechanical properties. In this paper we also present the results of residual welding estimation in samples welded using various technologies.We compared traditional technologies of heat treatment and deformation processing – ultrasonic and vibration treatment