Tensile Deformation Behavior and Fracture of FE-3.3%SI Steel at a Wide Range of Moderate Temperatures.

Abstract

The flow stress behavior of hot-rolled Fe-3.3%Si steel was studied through single-pass warm tensile experiments within the temperature range of 250 to 700 °C and strain rate range of 0.001 to 0.1 s -1 . The fracture morphologies and microstructures were also examined after deformation. The peak stress decreased linearly, but the elongation increased exponentially, with an increase in temperature. Work hardening behavior was obvious, and the non-uniform plastic deformation stage was shorter at lower temperatures, and accordingly grains were elongated. Significant dynamic recovery and recrystallization occurring in the alloy at deformation temperatures up to 550 °C resulted in some equiaxed grains in the microstructure. Fractures were ductile at lower strain rates and higher tension temperatures. Quasi-cleavage fractures were generated at higher strain rates, and cleavage fractures were generated on different planes in the range from surface to center.