Certain investigations on the intersecting cracks developed in high cobalt hard facing techniques

Abstract

Hardfacing is a surface enhancement technique in which the surface properties of industrial components such as agriculture tools, equipment s used for soil penetration and mining operations are enhanced from corrosion, abrasion etc. Hardfacing is a technique in which a homogeneous alloy is deposited on the surface of base metal by means of welding. As a result the hardness and wear resistance of the material can be enhanced without significant loss on the ductility and toughness of substrate material. Generally Cobalt base alloys and Nickel base alloys are used as base alloys for hardfacing. Gas Tungsten Arc Welding and Flux Core Arc Welding are the majorly used hardfacing processes. There are four important parameters that governs the hardfacing process namely dilution, microstructure, wear and mechanical properties. The present research work involves investigation on the Stellite 1 hardfacing of orifice plate used in offshore applications. First part of research work involve studies on establishing an effective deposition technique of cobalt-based Stellite1 on austenitic stainless steel (SS 304) orifice plate component, used in offshore application. Stellite1 hardfacing was done using gas tungsten arc welding (GTAW) and flux-cored arc welding (FCAW) techniques, which resulted in intergranular and longitudinal cracks. In finite element analysis (FEA), a three-dimensional solid model was generated and simulated for spot heat welding using ANSYS software. After simulation for heat distribution with and without weld bordering, crack-free hardfacing of Stellite1 was carried out and validated experimentally using FCAW technique. newline