Effect of test temperature on tensile behavior of Fe-6.5wt.%Si alloy as-cast strip

Abstract

The non-oriented Fe-6.5wt.%Si alloy as-cast strip is prepared by the top side-pouring twin-roll casting (TSTRC) process and the solidification structure of the as-cast strip is a uniform fine equiaxed grain structure. This paper studied the mechanical properties, fracture morphology, ordered phase morphology, and types of Fe-6.5wt.%Si alloy as-cast strips at different temperatures. The results show that the yield and tensile strength of the as-cast strip decreased gradually with the increase of tensile temperature, and the elongation after fracture increased gradually. The temperature rise prevented the formation of cleavage cracks, and the temperature rise is an effective method to improve the plasticity of Fe-6.5wt.%Si alloys. Concurrently, the ambient temperature is the main factor determining the tensile mechanical properties of Fe-6.5wt.%Si alloy at medium temperature. When the stretching temperature exceeds 500 °C, the Fe-6.5wt.%Si alloy has apparent plastic deformation ability. The Fe-6.5wt.%Si alloy exhibits excellent elongation when the stretching temperature is 700 °C. The serration fluctuations that appear on the 400 °C stretch curve should be attributed to the Portevin-Le Chatelier (PLC) effect caused by the reordering of the antiphase domains and the deformation-induced disorder. The Fe-6.5wt.%Si alloy as-cast strip is directly subjected to warm-rolling without the hot-rolling. When the warm-rolling is performed at the temperature of 700 °C, there are almost no cracks at the edge of the plate, the edge cracks are effectively controlled, and the surface quality of the warm-rolled sheet is fine. The obtained 700 °C warm-rolled sheets were cold-rolled at room temperature, and after recrystallization annealing, the sample had good comprehensive magnetic properties. Suppose the TSTRC-warm rolling-cold rolling-annealing process prepares the Fe-6.5wt.%Si alloy cold-rolled sheet. In that case, the production efficiency will be significantly improved, the process flow will be shortened, and the goal of energy-saving and emission reduction will be achieved.