High-thermostability in-situ nanophase-reinforced high-rigid steel and preparation method thereof

Abstract

The invention provides high-thermostability in-situ nanophase-reinforced high-rigid steel and a preparation method thereof. The microstructure of the high-rigid steel comprises a tempered martensite and nanometer-sized oxide-carbide composite in-situ nanophases which are dispersively distributed in a matrix, after vacuum melting, titanium is added in a wire feeding way, an ingot casting with target ingredients within a design range is obtained through electroslag remelting, the ingot casting contains a lot of high-melting-point titanium oxide in-situ nanophases, through hot rolling and quenched-tempered heat treatment, the high-thermostability oxide-carbide composite in-situ nanophase-reinforced high-rigid steel is obtained. A quenched-tempered heat treatment process window can be broadened, and the high-thermostability in-situ nanophase-reinforced high-rigid steel is obtained.

Description

【Technical field】 [0001] The invention relates to the technical field of alloy steel, in particular to a high-strength and tough steel with high thermal stability and in-situ nano phase strengthening and a preparation method thereof. 【Background technique】 [0002] With the exploitation of marine resources and the development of marine national defense, high-strength steel plates for marine use must have the characteristics of high strength, high toughness, easy welding, fatigue resistance, and corrosion resistance. The HSLA series of steel overcomes the problems of low impact energy and difficult welding of HY series steel, and greatly reduces carbon and alloy to improve the weldability of the steel. However, the resulting decrease in strength is solved by using nano Cu particles for reinforcement. However, HSLA series steels also have some technical shortcomings, such as the Cu nano-precipitation phase produced during the aging process, the size of the initial precipitati...

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Problems solved by technology

However, HSLA series steels also have some technical shortcomings, such as the Cu nano-precipitation phase produced during the aging process, the size of the initial precipitation is small and nearly spherical, and it maintains a coherent relationship with the matrix, but when it exceeds a certain heat treatment temperature (>550°C) will begin to coarsen and grow, and become irregular shapes (strips, rods, etc.), at the same time, the coherent relationship with the matrix gradually changes to non-coherent, and the result of this coarsening is seriously weakened. The precipitation strengthening effect of Cu nanoparticles is greatly affected, and the plasticity and toughness of steel are greatly affected, which seriously damages the overall mechanical properties of the material.

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