Per: FERNANDO DE SOUZA COSTA (USINAS SIDERURGICAS DE MINAS GERAIS SA), Paulo josé duarte rodrigues (USINAS SIDERURGICAS DE MINAS GERAIS SA), Guilherme Brito Menegaz Junior (USINAS SIDERURGICAS DE MINAS GERAIS SA)
Abstract:
Since the 1990s, Usiminas has been studying Advanced High Strength Steel (AHSS). Over time, this family of steels, which includes in its “First Generation” products such as Dual Phase (DP), Transformation Induced Plasticity (TRIP), multi-constituted Complex Phase (CP) and Martensitic (MART), has become a consolidated reality in the automotive industry. In recent years, however, the focus has been on the development of new AHSS, called “Third Generation AHSS”, which promises to include materials with even more complex microstructures, combining phases of high mechanical strength, such as ultrafine grained ferrite, martensite or bainite, and significant amounts of a constituent with good ductility (e.g., austenite). This work presents the main results of the development in laboratory scale of a third generation AHSS of the 1000 MPa strength grade, with TRIP effect, at Usiminas. For this purpose, several thermal cycles were performed in a Gleeble machine and in a dilatometer. The material obtained showed good microstructural homogeneity, high ductility in view of its mechanical strength grade, combined with good potential for energy absorption.