Recrystallization Behavior of IF Steel at the Interface of Al Junction

Abstract

The recrystallization behavior of a cold-rolled IF steel sheets, which had experienced recrystallization at higher temperature, was investigated at the active interface between IF steel and pure Al, heat-treated at 650ºC. In the region surrounded by the tongue-like η-Fe₂A_l5 phase, the recrystallized structure of the IF steel was characterized by equiaxed structure including subgrains, whereas elongated pancake shaped ferrite was majored in other region. The η phase grew preferentially to the c axis, and the growing η phase distorted the surrounding iron due to the difference in the molar volume; compressive deformation was expected both in the a-axis and b-axis directions, and tensile deformation was expected in the c-axis. The growth of η phase obviously changed the recrystallization behavior of the IF steel. The development of γ-fiber crystalline texture (<111>//ND), which was a typical recrystallization texture of IF steel, was not observed in the region surrounded by tongue-like η phase. The local misorientation in the vicinity of the two-phase interface could not explain the texture change in the region surrounded by the η phase. It was considered that the growth and restraint of the η phase also affected the nucleation of recrystallization.