Soldadura de aceros dual phase en chapa fina: GMAW, PAW y RSW

AUTOR(ES)
FONTE

Soldagem & Inspeção

DATA DE PUBLICAÇÃO

2011-06

RESUMO

Dual Phase steels (DP) have been used recently as an interesting option for structural elements, specialy in automotive industry, due to weight reduce requirements. Welding of these materials becomes particularly important considering their application as structural elements and the related manufacturing methods. In particular resistance spot welding (RSW) and gas metal arc welding (GMAW) are widely used in the automotive manufacturing. The plasma arc welding (PAW) has the charateristic, within arc welding processes, to involve the highest energy density, being this parameter interesting to certain applications on automative industry (tailor welded blanks). The objective of this work is to study the microstructural evolution and properties of welded DP steels by mean of RSW, GMAW and PAW. In this regard four DP steels, with tensile strength of 550, 700 y 850 MPa and thickness of 1 and 1.3 mm, were welded by mean of mentioned welding processes. Microstructures were charaterized and mechanical properties for each weld joint were determined. For the three processes good quality welded joints were obtained. It was observed on heat affected zone (HAZ) a softened zone whose hardness is below to initial base metal hardness. This softening is related to the dissolution of the martensitic phase due to thermal cycle introduced by welding. Arc welds were the most affected.

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