Research on Precipitation Behavior of Primary Carbides in 8Crl3MoV Martensitic Stainless Steel During Electroslag Remelting

摘要

Martensitic stainless steel has some excellent performance, such as high hardness, strength , good wear resistance and corrosion resistance. It was widely used in steam engines, high pressure vessels,~(1,2)knife and scissor products and so on. Currently, Cr13 stainless steel is the main material used in knife and scissor industry. This kind of steel has high corrosion resistance and hardness. However, for high-grade and longevous materials, its hardness cannot meet the requirement, which will cause the problems, such as edge turning taking place easily.~3 8Crl3MoV is a new material developed for high-grade knives and scissors. Its carbon content was raised to increase hardness, in addition, Mo and V were added to refine the grain size, improve toughness and tempered stability. However, with the increase of carbon content, many primary carbides were generated in steel. The size and distribution of these primary carbides had great influence on the mechanical property of material. These carbides can easily fall off from steel matrix, causing the edge collapsing of material.~4 This kind of defect is deadly for knife and scissor material. So, it was very important to control the size and distribution of primary carbides in steel used as knife and scissor materials. So far, reports about carbides mainly focused on the heat treatment stage.~(5,6) However, during heat treatment stage, it was difficult to eliminate defects caused by primary carbides. Primary carbides can also precipitate during Electroslag Remelting process. So, it was the fundamental way to control the carbides in this process. In this paper, effects of current intensity and cooling intensity on microstracture and primary carbides during ESR process were studied by optical microscope, SEM with energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Moreover, the mechanism of the effect of current intensity and cooling intensity on primary carbides distribution and morphology was discussed.