Abstract：During the detection of microstructures of cold rolled dual phase steel optical microscope， it was found that the traditional color metallographic technique still had difficulties in the identification of microstructure， especially for the dual phase steels containing bainite or residual austenitic phase besides of ferrite and martensite. At the same time， there were also confusions and difficulties in the measurement of area content of the second phase. The area content of the second phase under the corrosion of color metallographic technique and nitric acid-alcohol also had difference. Only the content of martensite could be quantified or measured for some samples. In order to solve these problems， the microstructure of cold rolled double phase steel with complex morphology was analyzed by SEM， optical microscope and color metallographic corrosion technique. Moreover， the qualitative and quantitative measurements of microstructures were conducted with the assist of several corrosion agents.
2020, Vol. 38 
