Production and characterization of dual-phase steels from an aisi 8620 steel with high mn content

Abstract

Dual phase steels are materials whose microstructure is composed of a ferrite matrix with martensite islands. Ferrite provides excellent ductility, while martensite increases the strength of steel, which provides a special appeal in the automotive industry. The main objective of this research is to obtain dual phase steels from AISI 8620 steel with a high Mn content, using heat treatments in the intercritical range to obtain approximate percentages of martensite of 27, 33, 41, and 48%. Microstructural characterization is performed using optical microscopy and scanning electron microscopy techniques. The mechanical characterization is carried out using hardness, tension and charpy impact tests. The highest mechanical resistance is achieved in steel with 41% martensite phase, while the highest ductility was obtained by the material with 27% martensite. A fractographic analysis of all materials allowed determining that the type of fracture presented is ductile. When the martensite fraction increases, the impact energy exhibits a decreasing behavior, while the hardness behaves in an increasing way.