Impact of Welding Consumables Strength Level on Metallurgical and Mechanical Properties Homogeneity of Welds Obtained with a Complex Phase Steel Patrícia Pala Diniz, Willy Ank de Morais

Abstract

There has been an increase in Advanced High-Strength Steels (AHSS) use in the automotive industry, including Complex-Phase (CP) steels that have a good combination of strength and ductility. However, despite the potential benefits of its higher mechanical strength (800 MPa), autoparts manufactured of CP steel are submitted to welding process with consumables with much lower level of mechanical strength. In order to offer an option to rationalize the use of this material in terms of welded joint, it were investigated joint performance of a pulsed GMAW welding process using ER70S-6 (class 70 psi or 482 MPa UTS) and ER110S-G (class 110 psi or 760 MPa UTS) consumables to join samples of CP-800 hot rolled steel (class 800 MPa UTS) with the same welding commercial parameters used nowadays. For this they were performed tensile, impact, hardness and metallographic tests in adequate welding samples. The results obtained in this work point to a better performance by using the ER110S-G consumable, but due to the lack of penetration in 4.0 mm thick plates it is recommended to use this consumable, under the same conditions of consumable welding ER70S-6 only on sheets up to 2.0 mm.