Influence of a cobalt-based wire injection in austenitic coating deposited via CW-GMAW

Abstract

The control of cavitation erosion wear is a hindrance concerning the maintenance of hydraulic equipment's. The most used consumables to fill eroded areas are cobalt-based austenitic steels, commercially known as ''Stellites''. The current study carried out analysis of the coatings deposited via the new cold wire gas metal arc welding (CW-GMAW) process. The coatings were deposited via CW-GMAW process, variating three levels of addition wire feeding speed. The coating consisted in a three-layer deposit; the first two with an AWS ER 309L wire, via GMAW process, and the third layer employed the interaction between AWS ER 309L and Stellite 21 E wires, via CW-GMAW process. The coatings obtained an increase in cobalt values, with silicon and molybdenum variations, as well as the iron value reduction for each used feeding variation. The coatings were subjected to an accelerated erosion test, according to ASTM G32 Standards. The best obtained result corresponded to the coating with 7.2 m/min additional speed.