Study of the Difference in Microstructures and Properties of Cold Rolled Dual Phase Steel with Different Composition

Abstract

The difference in microstructures and properties of 600MPa cold rolled dual phase steel with the different composition had been studied in this paper. It can be noticed that the Si-Mn-Cr steel have finer ferrite and more martensite whose content is about 25%; the Mn-Cr-Mo steel have coarser ferrite and some coarse pearlite as well as little martensite; the microstructures of the Mn-Al-Mo steel are consist of mainly ferrite which have even grain size and 16% martensite which distributed homogenously along the ferrite grain boundaries. The difference in microstructure makes the steel own the different properties. The Si-Mn-Cr steel has the highest tensile strength and yield strength but the worst elongation, the Mn-Cr-Mo steel has the lowest tensile strength, the Mn-Al-Mo steel has the an excellent mechanical properties with low yield strength and high tensile strength as well as higher elongation.