Additional nano enhancer capable of improving mechanical property of steel and preparation and using method thereof

Abstract

The invention discloses an additional nano enhancer capable of improving the mechanical property of steel and a preparation and using method thereof, and belongs to the field of ferrous metallurgy. The additional nano enhancer contains nano oxide particles and Fe, and the nano oxide particles refer to one of Y2O3, ZrO2, Ti2O3 or Ce2O3. The preparation method includes the steps of ball-milling coating, dehydration and crystallization, carbon-containing pelletizing and roasting membrane coating. The using method includes the steps that the additional nano enhancer is preheated and pre-laid at the bottom of a mold, and molten steel is injected into the mold. By the adoption of the method, Fe(OH)3 is used for pre-dispersing the nano oxide particles, OH-action is effectively destroyed and removed, the Fe(OH)3 can be gradually turned into Fe in the preparing process, and accordingly the additional nano enhancer can be prepared. In the casting process, the additional nano enhancer cannot influence the degree of purity of the molten steel, the nano oxide particles cannot denature and grow, either, a disperse distribution phase is formed when the nano oxide particles are added into the molten steel, and thus the mechanical property of the steel is effectively improved.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and provides an external nano-strengthening agent for improving the mechanical properties of steel and its preparation and use methods. Background technique [0002] Due to the use of deoxidizers and refractory materials in the process of iron and steel metallurgy, non-metallic inclusions will inevitably be generated or remain in steel. It is generally believed that non-metallic inclusions are harmful impurities in steel and the main cause of defects in steel products. Effective removal of non-metallic inclusions in steel has always been the direction of efforts of metallurgists. With the development of science and technology, relevant studies have shown that small-sized inclusions can be used as the nucleation centers of nitrides and carbides during solidification and thermal processing. By controlling the type, size, quantity and distribution of inclusions, the Comprehensive mechanica...

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Problems solved by technology

This process can effectively improve the mixing of nano-powders in molten steel, but due to the small particle size of pure iron powder, an oxide film (Fe 2 o 3 ), the existence of the oxide film will cause more free oxygen in the mixture, adding it to the molten steel will reduce the purity of the molten steel, and the timing of adding the molten steel is improper, and the nanoparticles are used as the nucleation center of other oxides to cause inclusions The change of type and size changed the original intention of joining

Chinese patent (CN104726639A) discloses a method for uniformly dispersing external nanoparticles in steel, using nano-oxides and low-melting-point nano-alloy powders for ball milling and mixing and pressing into blocks, and adding prefabricated blocks to molten steel through molybdenum rods, low The use of melting point nano-alloy powder can effectively improve the dispersion of nanoparticles in molten steel without reducing the purity of molten steel, but the addition of alloys to molten steel will cause changes in the composition of molten steel, resulting in smelting accidents and the use of molybdenum rods to stir or will cause molten steel to absorb oxygen

Although it can prevent molten steel from agitating and absorbing oxygen, it has not solved the problem of contamination of molten steel by adding low melting point alloys

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