Effects of Finish Rolling Temperature on Microstructure and Mechanical Properties of Ferritic-Rolled P-Added High Strength Interstitial-Free Steel Sheets

The steels were rolled at 3 different finishing temperatures. The mechanical properties were tested by tensile tests. The results show that as finish rolling temperature decreases from 620 to 560 ℃ in ferrite region,the deep drawability of ferritic-rolled P-added high strength IF steels is improved,and r value rises from 1.14 to 1.37. Finish rolling temperature (FT) has less influence on other mechanical properties,such as yield strength,tensile strength and elongation. Microstructures of hot rolled and annealed steel sheets and precipitates of annealed steel sheets were also analyzed.