Extrusion Press Plunger Submerged Arc Surfacing Welding Wear-resisting Development Of Flux Cored Wire

Press plunger, the main part of extruder, is usually working at harshconditions. In order to lengthen the life of the plunger, reduce the times ofreparation and cost, hard-facing alloy is built up with anti wear and anticorrosion properties. We developed a kind of metal wire, having powder inside,tailoring for35-steel matrix material, which is also known as LK-1flux-coredwire for submerged arc surfacing.In this paper, the powder composition was optimized and the metalpowder-cored wire with suitable transition coefficient of alloy elements wasmanufactured. The microstructure and composition of surfacing layer wereanalyzed by optical microscope, SEM and EDS respectively. And thecomprehensive mechanical properties of surfacing layer were investigatedthrough impact toughness test, the abrasive wear test and hardness test.A type of metal powder-cored wire which meets the design requirementwas successfully fabricated via comparison tests. The main factors that affectthe properties of deposited metal include chemical composition, microstructureand welding parameters. A group of optimized parameters were used in ourexperiments (Current:300~330A; voltage：30~32V; layer temperature:200~300℃; welding speed:40~60cm/min; stem elongation:30~40cm), there isno welding defects, such as cracking, voids and slag inclusion, and thedetachability of the metal powder-cored wire is favorable. The microstructureof the surfacing layer is composed of martensite and retained austenite throughthe observation of SEM and optical microscope. The hardness of surfacinglayer was enhanced by adding V and Ti. But the slag detachability was reducedfor V. The average impact energy of deposited metal is31.3J and the averagehardness of fused metal is46.8HRC. High wear resistance was also achievedthrough the tests.