EFFECT OF MICROSTRUCTURE ON SLURRY EROSION OF 13/4 MARTENSITIC STAINLESS STEEL

Abstract

Since the coming of the industrial revolution, steel has been mainly applied for consolidation of infrastructure for the development of economy. Yet the flow of materials in the form of slurry over the metallic construction has been the part and parcel of the growth procedure. Corrosion of metal surface due to cutting edges of the slurry particles has troubled the metallurgists and corrosion engineers over the last few decade. Erosive wear is an operation of intensive degradation of metallic surface layers when solid particles impinge upon them. The resistance to erosion depends on working conditions and the parameters of the worn out - material like toughness, hardness and microstructure. This task aims at getting the most suitable microstructure of plain carbon steel for erosion wear resistance. Plain carbon steels are more often than not employed in conventional word of mouths which may get damaged below the influence of high speed slurry impingement leading to the failure of pipelines. Therefore, it is really important to develop more erosion resistant material. Thus, the purpose of our present work is to come upward with the steel that have best competency against slurry erosion. In my work, effect of diffent types of heat treatments on slurry erosion response of 13Cr- 4Ni rnartensitic stainless steel (MSS) is being studied. The as received samples of MSS were subjected to different heat treatments. These heat treatments consists of the austenitization of cast steel at 1000°C temperature for soaking duration of 2h, 4h and 6h. This process has been followed by oil quenching then tempering at 600°C for lh, 2h and 3h for each Austenizing temperature, followed by air cooling, and subsequently tested for slurry erosion with silica (SiO2) particles (210-312) microns with the speed of impact 3.66 m/sec. Characterization of heat treated samples were done for microstructure and mechanical properties viz, hardness, ductility (% elongation), and tensile strength (UTS). For characterization of wear, slurry erosion tests were done for as-received cast and heat treated samples, and then SEM images of fractured samples and eroded samples were taken. The heat treated MSS shows lesser weight loss as compared to as-received cast MSS. Increase in toughness of heat treated samples is found to be responsible for the improved slurry erosion resistance in the heat treated sample.