Nitrogen intensified high-carbon twin crystal inducement plastic steel material and its production technique

Abstract

The invention relates to a technology for improving an iron and steel metallic material, in particular to a nitrogen-strengthened high-carbon twin-crystal induced plastic steel material and a method for preparing the same. The steel material is characterized by comprising the following component ranges: 0.2 to 1.0 percent of C, 15 to 35 percent of Mn, 0.04 to 0.2 weight percent of nitrogen content in control, less than 1 weight percent of Al, less than 1 weight percent of Si, less than 0.008 percent of S, less than 0.02 percent of P, and the balance being Fe. The stacking fault energy is controlled to between 20 and 60 mJ.mm<2>. The technology can obtain the proportions of strength and plasticity of different levels through process control so as to obtain the tensile strength of between 995 and 1,530MPa, the yield strength of between 470 and 1,340 MPa and the specific elongation of between 13 to and 71.5 percent. The steel material does not have a turning point of the flexible brittleness. The high-strength high-plasticity steel materials prepared by the technology can be used in the industries such as railway steel rail, saloon sedan manufacturing, engineering machinery, oil-gas delivering pipeline and liquefied natural gas container, military industry, and have important value and great application space.

Description

technical field [0001] The invention belongs to the field of iron and steel material preparation, and relates to a nitrogen-enhanced high-carbon twinning-induced plastic iron and steel material and a preparation method thereof Background technique [0002] Twin-induced plasticity steel is a pure austenitic carbon steel mainly composed of Fe and Mn. After annealing, the structure at room temperature is austenite, accompanied by a small amount of flaky annealing twins and stacking faults. After stretching, the grains A large number of mechanical twins are generated inside, and the plasticity is induced by hindering the movement of dislocations through the twin boundaries, so that the matrix has high ductility and high plasticity. [0003] In recent years, research on the superior high strength (600-1200MPa), high plasticity (maximum elongation up to 95%), and high toughness (-196°C steel has a total strain of 65%) of twin-induced plasticity steel has made a kind of New means ...

AI Technical Summary

Problems solved by technology

Because the composition of traditional TWIP steel is Fe-25Mn-3Al-3Si-0.03C (Document 1: Georg Frommeyer, Udo Brux, PeterNeumann.Supra-ductile and high-strength manganese-TRIP / TWIP steels for high energy absorption purposes, ISIJ International , V43(2003) 3: 438-446.) Among them, the Al content is relatively high, because Al is easily oxidized during casting, which will block the casting nozzle, and high content of Si will affect the galvanizing quality of cold-rolled sheets. These problems will cause It brings difficulties to the industrial production of TWIP steel, so it is necessary to develop a new generation of low-Si and low-Al TWIP steel