The paper deals with cold rolling and ageing on microstructure and mechanical properties of 2507 duplex stainless steel. Microstructure depicts acicular/Widmanstatten austenite and delta-ferrite with dissimilar volume fraction (similar to 0.55 for ferrite and similar to 0.45 for austenite). Cold rolling and ageing at 950 degrees C, 1000 degrees C and 1050 degrees C result in equiaxed austenite for samples solution treated at 1040 degrees C and elongated at 1300 degrees C. By lowering ageing temperature from 1050 degrees C to 950 degrees C, structure becomes finer from similar to 20 mu m to <10 mu m grain size. The sigma (sigma) phase appears after ageing at 950 degrees C. Micro-hardness reveals maximum hardness for the hot rolled, solutionized (1040 degrees C) water quenched, and cold rolled (50 %) sample (380 HV delta F 100 and 430 HV gamma 100), whereas the tensile results reveal the hot rolled, solution treated (1300 degrees C, 1040 degrees C), cold rolled and aged at 950 degrees C samples show higher strength (yield strength=625 MPa, 567 MPa and ultimate tensile strength=892 MPa, 826 MPa) and lower ductility (23 %, 32 %) due to the sigma-phase. The solution treated (1040 degrees C), cold rolled, aged at 1050 degrees C sample exhibits attractive strength and ductility combination (similar to 30 GPa %). Fractography supports the tensile results.
