Analise da influência da temperatura no pré-aquecimento em solda de aço de alto carbono SAE 5160

Abstract

A widely used process for metal joining in the industry is welding, which is vital for industrial progress, being employed from the manufacturing stage to maintenance. However, when this process is applied to high-carbon steels, there is a risk that it may not be effective due to a microstructure favorable to hydrogen inclusion along the weld bead, causing cracks and porosity. To address this problem, this study aims to analyze the effect of the preheating technique on SAE 5160 steel, which is known for its high hardenability and low weldability. The process used a muffle furnace to ensure uniform heating of the entire piece, so that during welding, the piece cools more slowly, thus avoiding the formation of martensite. The preheating was conducted above the recommended temperature range. The welding process was performed using the shielded metal arc welding (SMAW) method. This approach allows for analysis through Rockwell hardness testing to determine the material's hardness parameters, and metallographic analysis using an optical microscope to examine the resulting microstructure of the weld bead susceptible to hydrogen diffusion. The study concluded with a notable reduction in martensite areas.