EBSD Study of Martensite in a Dual Phase Steel

Abstract

Dual phase steel microstructures are predominantly equiaxed ferrite with martensite volume fractions varying from about 10 to 20%. The steel for this study is a plain low carbon (0.09%C) grade, donated by Ivaco, Canada. The dual phase structure was generated by annealing at a temperature of 750 o C (i.e. in the two phase austenite plus ferrite region), followed by a water quench after a hold time of 5 minutes, to transform the austenite to martensite. After mounting, the specimens were mechanically polished using SiC, 1 m diamond paste and 0.05 m colloidal silica, in succession. To obtain the EBSD data, a Philips XL-30 FEG with TSL orientation imaging system was used.