Microstructure and Mechanical Properties of Hot-Rolled Low-Carbon Medium-Manganese TRIP Steels

Abstract

Transformation Induced Plasicity (TRIP) steels have attracted a growing interest in recent years due to their high strength and ductility combination.An alternative alloy and processing concept has been studied to evaluate the feasibility of producing low-carbon medium-manganese TRIP Steels. Conventional hot-rolling, and batch annealing processes were simulated with three laboratory heats of varying manganese content. The steels were found to be fully hardenable with conventional hot-strip mill processing and subsequent batch annealing simulations produced significant retained austenite levels. The combination of the prior martensitic microstructure in the as-hot-rolled condition, and austenite created during annealing,resulted in remarkable combinations of strength and ductility. Optimum properties were found when samples were annealed at approximately 630°C. While this treatment maded the tensile strength to 800-1020 MPa, the total elongation increased to between 27 percent and 35 percent. UTS*TE products exceeding 30,000 MPa*% were observed, making these materials attractive for high strength, high ductility applications.

Study on static softening behavior and hot working performance of Fe-0.2C-7Mn steel

“…Among them, medium Mn steels containing 5∼12% Mn usually show an ultrafine dual-phase microstructure composed of ferrite and retained austenite (RA) after IA [3,4]. Austenite grains with appropriate stability transform to martensite gradually during plastic deformation (TRIP effect), which is beneficial to the strength and plasticity [2,5]. Due to such microstructure, grain refinement is an effective way to enhance the mechanical properties.…”

Effect of Reverse-phase Transformation Annealing Process on Microstructure and Mechanical Properties of Medium Manganese Steel

“…Strength and plasticity are important indexes of steel materials. In general, the high strength which reflects in plasticity and toughness are low, and good matching with high strength as well as high plasticity is a necessary condition for automobile components [ 1 , 2 , 3 , 4 , 5 ]. The first generation of automotive steel, represented by IF steel and DP steel cannot meet the dual requirements of light weight and high safety.…”