The Process Control And Properties Research Of TRIP Steel

TRIP(Transformation Induced Plasticity) steel is the most potential automobile steel at present. It has the high strength and high ductility at the same time. The tensile strength can exceed 1200 MPa, and the total elongation can reach 30%. The adjustable range of properties for TRIP steel is very wide, and the TRIP steel with the different component can get the different combination of strength and ductility, which can meet the different demand of Suspension System, drive system and security structure, etc. The TRIP steel which is studied in the paper is low carbon Si-Mn TRIP steel which designed and rolled by myself.Low carbon Si-Mn TRIP steel is usually multi-phase microstructure, which is mainly made up of ferrite(F), bainite(B) and retained austenite(A'). The acquisition of TRIP effect is through the transformation of retained austenite to martensite, then, reaching the aim of strengthening and toughening the steel. In this paper, different microstructure is obtained through using the different heat treatment progress, the microstructure at the different heat treatment is analyzed through the optical microscope, scanning electron microscope and transmission electron microscope, the mechanical properties of experimental steel after heat treatment is tested through using the tensile experiment at the different tensile rate, detecting the change of content of retained austenite fore and after tensile using the X-ray diffraction and researching the relation between the microstructure and properties, analyzing the fracture mechanism and method of the experimental steel according to the microscopic and macroscopic pattern of nick.