Análise dos efeitos da soldagem TIG autógena no aço DP 1200 galvanizado

Abstract

The use of AHSS (Advanced High Strength Steels) has been increasingly widespread in the automobile industry. However, some steels of this classification, such as DP steels, need to be studied more deeply for a possible application in the sector, due to the material properties after the welding process. One of the least used processes for joining DP steels is the TIG welding process. Thus, this study aims to analyze the effects of autogenous TIG welding on galvanized DP 1200 Steel. Analyzing the material after welding to verify the thermal cycle and its influence on the material's mechanical properties. An increase in welding energy and heat input was observed when compared to the filler metal material. This fact affected the mechanical properties of the material because the large amount of heat in the plate favored phase transformations, the appearance of the retained austenite phase was of fundamental importance for the mechanical responses of the material, such as microhardness, toughness and traction. The material had lower tensile strength limit values when compared to the material as received. Based on the results obtained, it is possible to conclude that the autogenous TIG welding process for DP 1200 steel presented changes in the welding thermal cycle, microstructure and mechanical properties, when compared to the same process using filler metal.