Multiphase composite high-strength high-toughness low-density steel and preparation method thereof

Abstract

The invention discloses multiphase composite high-strength high-toughness low-density steel and a preparation method thereof, and belongs to the technical field of metal materials and metallurgy. The multiphase composite high-strength high-toughness low-density steel is prepared from the following chemical components in percentage by mass: 1.05 to 1.10 wt.% of C, 27.0 to 28.0 wt.% of Mn, 10.3 to 11.0 wt.% of Al, 3.0 to 3.5 wt.% of Cr, 0 to 3.6 wt.% of Ni, 0.02 to 0.04 wt.% of Nb, less than or equal to 0.01 wt.% of S, less than or equal to 0.005 wt.% of P and the balance of Fe and inevitable impurities. The preparation method comprises the following steps: smelting and casting according to the component proportion, homogenizing, forging into a square billet, homogenizing, carrying out multi-pass hot rolling and water cooling, and carrying out solution treatment. According to the multi-phase composite high-strength high-toughness low-density steel with low cost and high efficiency and the preparation method thereof, the components and the content of microalloying elements are selected, and the preparation mode is adopted.

Description

technical field [0001] The invention belongs to the technical field of metal materials and metallurgy, and relates to a multi-phase composite high-strength, high-toughness and low-density steel and a preparation method thereof. Background technique [0002] Usually, the design scheme of high-strength low-density steel is to obtain an austenite matrix and dispersed nano-scale κ carbides through a reasonable ratio of Mn, Al, and C alloying elements, followed by solid solution or aging treatment. However, κ carbides have a great influence on the properties of low-density steels. Although they can increase the strength, they will also increase the brittleness of the material. [0003] At present, although there are low-density steels obtained by adding alloy elements and mediating preparation methods, the obtained low-density steels not only have higher density, but also have low elongation, and the phase structure is mostly precipitation strengthening phases, which cannot be we...

AI Technical Summary

Problems solved by technology

[0007] The technical problem solved by the present invention is that the density of the existing austenitic low-density steel is not greatly reduced, the selection of microalloying element components is complicated, and the cost is high; heat treatment forms The phase structure of the steel cannot be well coordinated to improve the strength and toughness of the steel, and the phase composition is not easy to control

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