Method for adding nano particles into steel, refining structure and strengthening and toughening steel

Abstract

The invention relates to a method for adding nano particles into steel, refining a structure and strengthening and toughening steel. The method comprises the following steps that firstly, the nano particles are pre-dispersed, oxide nano particles and pure metal nano powder are weighed and are mixed, and a mixture is subjected to pre-dispersing in a planetary ball grinder under the vacuum and liquid nitrogen cooling condition to obtain mixed nano powder; secondly, an aluminum-based intermediate is prepared, a medium-frequency induction furnace is adopted for heating and melting metal aluminum,the mixed nano powder is added, and under the joint effect of a spiral electromagnetic field and ultrasonic waves, the mixed nano powder is dispersed in the molten aluminum to obtain the aluminum-based intermediate; and thirdly, the nano particles are added, in the deoxidized alloying process in the RH refining later period, silicon, manganese, aluminum or alloy of silicon, manganese and aluminumis adopted for deoxidizing the molten steel, the aluminum-based intermediate is added, and in the continuous casting production process, a continuous casting blank with the nano particles evenly distributed is prepared. Aluminum alloying is achieved, and after aluminum dissolving, the nano particles are released to be dispersed in the molten steel.

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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