Study of martensitic-ferritic dual phase steels produced by hot stamping

4th International Conference Recent Trends in Structural Materials

Eriir, E.^1 ; Bilir, O.G.^1

Department of Metallurgical and Materials Engineering, Kocaeli University, Kocaeli

41380, Turkey^1

关键词: Annealing temperatures;    Effects of heat treatment;    Final microstructures;    Hot stamping process;    Initial microstructures;    Micro-structural characterization;    Total elongations;    Yield and tensile strength;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/179/1/012022/pdf
DOI  :  10.1088/1757-899X/179/1/012022

来源: IOP

【 摘 要 】

The effects of heat treatment and initial microstructure on tensile properties of 22MnB5 and 30MnB5 high-strength hot stamping steels with martensite-ferrite matrix were investigated. Hot stamping steels possessed limited elongations of about 5% in a tensile strength ranging from 1300 to 1500 MPa when quenched at temperatures above A3 temperatures. The total elongations were tried to improve by partial austenization between Ac1 and Ac3 temperature and quenching. Ac1 and Ac3 temperatures were calculated via ThermoCalc. Microstructural characterization was made by using Light Microscope and Scanning Electron Microscope. Microstructure is composed of ferrite+martensite. It was seen that annealing temperature affects the volume fraction of phases. It was concluded that initial microstructure is an important parameter for the final microstructure. This method can be used for automobile parts which require higher TE with sufficient yield and tensile strength. Also this process may be a way of using Zn coated steel sheets in hot stamping process.