Study On On-line Spheroidizing Of GCr15Steel

Different technologies of on-line spheroidizing used for GCr15steel are worked outby DET (divorced eutectoid transformation) and spheroidization of lamella in this article.The influence of different technologies on spheroidizing of microstructure and softening ofmaterial has been discussed by comparing microstructure and hardness, through thethermal simulation method. It could provide experimental and theoretical supports forstudying on on-line spheroidizing of GCr15steel.The subsection cooling method of slowly cooling follow rapid cooling has beenadopted after sample austenitizing at high temperature, and the influence of technology onthe spheroidizing of microstructure by DET has been analyzed.The results indicated thataustenite grain couldn’t be refined through the subsection cooling without deformation, andit is difficult to precipitate dispersed carbide particles along grain boundary. So it couldn’trealize spheroidizing of microstructure and the effect of softening material is very limited.The method of induce carbide particles precipitate out dispersedly during thedeformation use the effect of deformation induced precipitation has been adopted, and theinfluence of technology on the spheroidizing of microstructure by DET has been analyzed.The results indicated that the number of carbide particles is small because carbideprecipitation is very limited due to short time of deformation. So it is very difficult torealize spheroidizing of microstructure and the effect of softening material is limited.The method of induce carbides precipitate out in large quantity first use the effect ofdeformation induced precipitation, and then break the carbides into graininess bydeformation has been adopted. The influence of technology on the spheroidizing ofmicrostructure by DET has been analyzed. The results indicated that amounts ofspheroidized microstructure could be obtained because a large number of dispersedcarbides which were conducive to break by deformation could precipitate before the two-phase zone deformation. The effect of softening material is obviousThe method of induce pearlites forming in large quantity first during the deformationuse the effect of deformation induced phase transformation, and then break the lamella bydeformation for fusing has been adopted. The influence of technology on the spheroidizingof microstructure by spheroidization of lamella has been analyzed. The results indicatedthat small lamellar pearlite could be induced during deformation and a large number ofdislocations inside cementite lamella formed by continue deformation is conducive tofusing. Amounts of spheroidized microstructure could be obtained and the effect ofsoftening material is obvious.