Influência da temperatura final de laminação nas propriedades mecânicas de aço da classe 500 Mpa de limite de resistência processado por TMCP

Abstract

The production of thick plates with the accelerated cooling technology aims at providing a variety of products with enhanced mechanical and metallurgical properties in relation to conventional steels. The steels obtained through TMCP (Thermo-Mechanical Control Process) show lower results of carbon and alloying elements, which implies greater welding capacity, formability and elimination of additional heat treatment processes. From 500 MPa of tensile stress are produced by TMCP for application in agricultural implements, with the certification of excellent surface quality. This is a challenge for the production of thick plates for thickness smaller than 19 mm due to the formation of scale between the mill and the accelerated cooling system. In order to minimize the mill scale, it is necessary to reduce the finishing temperature, with finishing rolling at temperatures close to or below the initial temperature for transformation the austenite (Ar3), which implies the initial accelerated cooling with the material partially transformed. Thus, this work compared and evaluated the effect of the finishing temperature on the microstructure, mechanical properties and surface quality of a high strength structural steel processed through TMCP, increasing the technical knowledge regarding the Rolling Plate rolling process, besides providing subsidies for the development of the manufacturing process of this product with thickness smaller than 19 mm.