During the isothermal transformation, the volume fraction of pro-eutectoid ferrite does not follow the lever rule expressed in the equilibrium phase diagram. Thus, the carbon content in the pearlite varies with the heat treatment conditions. Since car...
During the isothermal transformation, the volume fraction of pro-eutectoid ferrite does not follow the lever rule expressed in the equilibrium phase diagram. Thus, the carbon content in the pearlite varies with the heat treatment conditions. Since carbon content in pearlite is varied with chemical compositions and heat treated conditions, the variation of microstructural features such as volume fraction and the thickness of the cementite should be considered even at the same interlamellar spacing. Thus, the variations of microstructural features with carbon content and transformation temperatures were investigated, correlating with the variations of mechanical properties. In eutectoid steels, interlamellar spacing increases with the increase of transformation temperatures. But, interlamellar spacing does not seem to correlate with the increase of austenitizing temperature. The effect of increasing transformation temperatures resulted in the decrease of strength and the increase of ductility.