PECULIARITIES OF STRUCTURE FORMATION OF LOW-ALLOYED STEELS DURING HEAT TREATMENT OF PLATES IN – LINE OF THE ROLLING MILLS

Abstract

Mechanism of austenitization of steels with inital pearlitic-ferritic and austenitic-ferritic structures was studied. In steels with ferritic- pearlitic structure the oriented formation of austenite at boundaries of of ferritic grains and its growth along certain crystallographic planes was found.. It is the evidence of widmanstatten nature of this polymorphous α → γ transformation. At heating of steel with initial austenitic-ferritic structure process of austenite formation during following heat treatment with phase transformation is not accompanied by expected grain refinement. It this case heat treatment does not provide increasing of complex of mechanical properties of rolled plates in comparison with hot rolled state