Microtexture Study of Warm-Rolled High Strength Interstitial-Free (IF) Steel Sheets

Interstitial-free (IF) steel has excellent deep-drawability and was used widely in automotive industry. High strength IF-steel is that some phosphorus was put in common IF-steel to improve its strength without destroying the deep-drawability [1]. Microstructure and grain boundary character strongly affect the deep-drawability of high strength IF-steel, it is an obligatory task to test those characters. The technique of Electron Backscatter Diffraction (EBSD) can reveal the microtexture and detailed orientation distribution of grains from a single EBSD map, as a powerful instrument, EBSD was used widely in materials research from last decade [2]. Many researches have been focused on the texture evolution and recrystallization phenomena of high strength IF-steels [3,4], but the microtexture and grain boundary characters of warm-rolled high strength IF-steels was not fully investigated. The present study was aimed at researching the microtexture characters of a commercial high strength IF-steels under different warm-rolled temperature using EBSD technique, the microstructure and grain boundary character were analyzed systemically, and the relationship between the microstructure and deep-drawability was discussed.