Avaliação do efeito da aplicação de vibrações mecânicas sobre os níveis de tensões residuais em juntas soldadas de aços ASTM A516 Gr.60.

Abstract

Nowadays with the high growth of petrochemical welding technology a great development due to high manufacturing offshore structures, storage tanks of petroleum, boilers and pressure vessels for refining plants have been done. Due to various metallurgical changes and restrictions to contraction and expansion undergone by materials when subjected to welding thermal cycle, internal stresses are generated in welded joint which are nominated residual stresses. It is generally undesirable because it can lead to several problems, such as cold cracks, stress corrosion cracks, among others. Although several studies involving residual stresses have been developed in recent years, little information’s known about the variation of the residual stresses level in welded joints when subjected to the treatment of stress relief by mechanical vibration. Likewise, there are little information related to the comparison between the degree of efficiency by using the post-weld heat treatment and those treatment. . Therefore, the goal of this work was to apply the relieve residual stresses treatment by mechanical vibration in ASTM A516 Gr 60 steel welded joints used in oil industry, and compare the results with those obtained by post heat treatment and evaluate the efficiency level of this technique In addition, this works also hope to contribute for a better understanding of this technique and to find which parameters have a greater influence on the results.