Determinação das tensões residuais de soldagem em tubos de aços inoxidáveis superduplex

Abstract

The aim of this study is to evaluate the effect of heat input on welding residual stress in superduplex stainless steel pipes. The welds were made in robotic workbench using the FCAW process. Welded joints were manufactured with different heat inputs (0.5, 1.0 and 2.0 kJ/mm). It was used a mini X-ray portable diffractometer for measurement of residual stresses. The determination of residual stresses in each phase individually considered the family of crystallographic planes {211} of ferrite and {220} of austenite. The results showed that the levels of stresses provided to lower heat input was low in the weld region. With the increase in heat input the stress levels was increased. The microscopic analysis revealed that the ferrite to low heat inputs is subject to tensile stresses and the austenite to compressive stresses. For highest heat input an inversion behavior was observed.