A dual phase steel have been developed, where it contains 0.13% carbon in addition to different Si & Cr contents.Allotropic and polymorphic transformation temperatures of investigated steel were calculated by using JMatPro7 software. The designed rolling passes considered the phase transformation temperatures.Two stages hot flat deformation were used for thickness reduction. 1ststage was carried out by forging for a thickness reduction from 36 to 8 mm. 2ndstage was finish hot flat rolling to reduce the thickness from 8.0 to 3.0 mm through 5-consecutive passes.A numerical model was constructed and built based on the Z- parameter calculations for expecting of the austenite grain size. The numerical model was verified by using the data of the designed rolling passes. The model expect austenite grain size is 0.24 micron after the last pass.After finish hot rolling, the strips were then subjected to austentizing at 900oC and holding for 30 min., followed by a double quenching process. First quenching is done in a salt bath at 450oC for 7, 14 and 21 min. Finally the strips were then water quenched to the room temperature. It was found that created martensite colonies are executing with the bainite aggregates in a ferrite matrix.Tensile testing possesses continuous yielding phenomena even at the hot- rolled strips as a result of martensite creation, while elongation decreases. Ductility still reasonable for sheet metal forming in the range of 12-16%. The optimum time of salt bath treatment was concluded as 7 min.
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