Welding heat input effect on the corrosion resistance of a 414-N stainless steel cladding deposited by FCAW welding

Abstract

In continuous casting process, rollers are used for the containment, support, conduction and transport of the slab. To substantially extend the life of the rollers, the surface is covered with a wear-resistant coating called hardfacing which is applied by means of recharge welding to improve the surfaces that are subject to severe wear, oxidation or corrosion of the surfaces. The objective of this work is to study the effect of welding heat input on the corrosion resistance of a martensitic stainless steel AISI 414-N applied as a hardfacing in synthetic seawater. Welding process for the application of the recharges was FCAW. The electrochemical techniques were potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS). The results indicate that all the hardfacing have a lath martensitic structure, where 26 V presented 5.44% ferrite, 28 V 5.33% and 30 V 5.0%, it can be seen that with a high heat input used, the smallest ferrite amount is obtained. From the electrochemical results it can be observed, for 30 V, the most active behavior has an E_corr of -535 mV / ECS, being for 26 V and 28 V the noblest values (-380 mV / ECS and -425 mV / ECS ) respectively. For 28 and 30 V passivity rupture potentials (313 mV / ECS and 132 mV / ECS) are presented, respectively.