INHOMOGENEOUS TEXTURE FORMATION IN HIGH-SPEED HOT-ROLLING OF FERRITIC STAINLESS-STEEL

Effects of inhomogeneous shear strain on the texture variation through the thickness of hot rolled ferritic stainless steel sheets are studied. The changes in texture with the progress of recrystallization are also investigated. Sheet specimens of AISI430 stainless steel are rolled at 1 000-degrees-C at a rolling speed of 20 m/s without lubrication and quenched into water at an interval of 3.5 to 250 ms after rolling. The redundant shear deformation by friction produces a severely sheared region beneath the surface, where a band of extremely fine recrystallized grains is formed when the strain exceeds a critical value. <110> parallel-to ND axis density increases and <111> parallel-to ND axis density decreases with increasing shear strain. The deformation texture in the severely sheared region mainly consists of {110}<001>, {110}<112> and {112}<111>. At the mid-thickness, it consists of <111> parallel-to ND and <100> parallel-to ND components. Only shear deformation is required for the formation of {110}<001> texture. The sharpness of the preferred orientation decreases by the progress of recrystallization, but some components of deformation texture are retained throughout the thickness after recrystallzation is completed.