A method for adding nano particles to steel and refining its structure and strengthening and toughening steel

Abstract

The invention relates to a method for adding nanoparticles to steel and its refined structure and strengthening and toughening steel, comprising the following steps: (1) pre-dispersing nanoparticles, weighing oxide nanoparticles and pure metal nanopowder, and or mixed, and pre-dispersed in a planetary ball mill under vacuum and liquid nitrogen cooling conditions to obtain a mixed nano-powder; (2) prepare an aluminum-based intermediate, use a medium-frequency induction furnace to heat and melt metal aluminum, add a mixed nano-powder, in a spiral electromagnetic field and Under the joint action of ultrasonic waves, disperse and mix nano-powders into molten aluminum to obtain aluminum-based intermediates; (3) Add nanoparticles. During the deoxidation alloying process in the later stage of RH refining, silicon, manganese, aluminum or their alloys are first used to react with molten steel Deoxidation is carried out, and then aluminum-based intermediates are added. During the continuous casting production process, continuous casting slabs with uniform distribution of nanoparticles are prepared. The invention realizes the aluminum alloying, and releases nano particles to disperse into the molten steel after the aluminum is dissolved.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a method for adding nano particles to steel and refining its structure and strengthening and toughening steel. Background technique [0002] With the development of science and production technology, the requirements for steel quality are getting higher and higher. It is required to greatly increase the strength of steel while ensuring or improving its plasticity and toughness. These performance characteristics are closely related to the internal structure of steel. Studies have shown that compared with the ferrite-pearlite structure, the structure of steel is mainly acicular ferrite, which can improve its strength and ductility at the same time. In recent years, the addition of alloying elements + controlled rolling and controlled cooling has been used at home and abroad to obtain a large amount of acicular ferrite, but this method is only effective for special steels, a...

AI Technical Summary

Problems solved by technology

The added second-phase particles are generally nano-scale particles. Due to the large specific surface area and high reactivity of nanoparticles, they are easy to agglomerate and grow when added to high-temperature molten steel, and even become harmful inclusions in steel, losing the effect of refining grains.

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