Research and Development of the Third Generation Steels for Automobile with Ultra-High Strength and Product of Strength and Elongation Based on Strength and Plasticity Enhancement by Multi-Dimensions Mechanisms(PDF)
MATERIALS CHINA[ISSN:1674-3962/CN:61-1473/TG]
Issue:
2018年第10期
Page:
56-60
Research Field:
特約研究論文
Publishing date:
Info
Title:
Research and Development of the Third Generation Steels for Automobile with Ultra-High Strength and Product of Strength and Elongation Based on Strength and Plasticity Enhancement by Multi-Dimensions Mechanisms
(1.School of Metallurgy Engineering, Anhui University of Technology, Maanshan 243032， China)(2.School of Iron and Steel, Soochow University, Suzhou 215021,China)(3.School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243032,China)
The research and development of the third generation automobile steels were summarized and analyzed in this paper. The mechanism for enhancement of elongation at ultrahigh level of strength mainly was increasing the volume fraction of retained austenite (RA) in the current researches. However, it is very difficult to be applicable in the industries to achieve the high product of strength and elongation only by the mechanism of RA, resulting in that the third generation automobile steels have not been practically manufactured and applied widely during the past decade. In order to increase the elongation under the condition of ultrahigh strength, it is required to combine all of possible mechanisms for plasticity enhancement other than only by RA mechanism, in which the development of new alloying system and new technical route is necessary. Based on the theoretical analysis and primary results, a novel technical route called as “Multidimension Mechanism” was proposed, in which the strength and elongation would be increased simultaneously by the combined effect of Precipitation, Refine of microstructure and Multiphase design (PRM). The primary experimental results were analyzed by taking the newly designed CrMn microalloyed steel as an example. The results illustrated that enhancement of elongation at the ultrahigh strength level could be industrially achieved with lowcost, low energy consumption and easily popularizing for the manufacturing and application in the third generation automobile steels based on present cold rollingannealing processing through new alloy designs and technical routes. Novel ideas have been proposed in the paper, which will be helpful to resolve the key problem of elongation enhancement in the ultrahigh strength steels including the third generation automobile steels.