Preparation process of nano powder modified and reinforced die steels

Abstract

The invention relates to a technical device for preparing nano powder modified and reinforced die steels. The preparation process comprises the following steps: pre-dispersing and mixing pretreated nano reinforced particles together with pre-dispersed iron powder in a stirring-type ball mill, preparing into dispersed prefabricated blocks, adding in steel ladle, dispersing the nanoparticles in a die steel matrix by a block dispersion method, enabling the nano particles to evenly disperse in the die steel matrix and metal wear resistant material matrix by utilizing an electromagnetic stirrer, and moulding by a casting method. The invention adopts nano particle modification process to improve the wettability of the nanoparticles and matrixes, obtain the die steels with evenly distributed nanoparticles by secondary dispersion and an electromagnetic stirring technology and enable the steels to be modified and reinforced. By adding nanoparticles with different materials, the modified die steel can have different properties so as to satisfy different requirements of service conditions; and by adjusting the addition amount of the nanoparticles and the volume fraction thereof, on the premise of ensuring the material impact roughness, the larger the nanoparticle volume fraction is, the higher the material wear resistance is. The nano powder modified and reinforced die steel in the invention has excellent mechanical performance, simple production process and low manufacture cost.

Description

technical field [0001] The invention belongs to the technical field of die steel, and relates to a preparation method of nano powder modified strengthened die steel, in particular to a preparation process of nano powder modified strengthened die steel. Background technique [0002] Mold is the basic process equipment of industrial production and the main indicator to measure the level of product manufacturing in a country. Die steel is the most important technical and material basis of the mold industry. Its variety, specification, performance and quality are decisive for the performance, life, manufacturing cycle and industrial products of the mold to the direction of advanced, diversified, personalized and high added value. Therefore, the research and development of die steel has always been valued by various countries. [0003] With the development of modern mechanical equipment and manufacturing technology, higher and more stringent performance requirements are put forw...

AI Technical Summary

Problems solved by technology

However, this process is only prepared by using the microalloy grain refinement widely used at home and abroad at present, and the principle of inhibiting the grain growth of steel by alloying elements, especially the use of niobium (Nb) in the metal crystallization process. If it can suppress recrystallization and improve the recrystallization temperature of the material, the manufactured steel ingot still belongs to the range of fine-grained steel and cannot be called nano-alloy steel.

Moreover, this process combines high-purity metal liquid and microalloying to form certain nucleation particles inside the steel. Since these particles are almost precipitated in the austenite below the solidus line, the austenite itself is The nucleation of the core cannot play the role of nucleation core, that is, it has no effect on refining the as-cast grains, and can only act as a pinning hindrance to the grain growth in the later thermal processing process, so there is a requirement for the purity of molten steel High, the quality stability of the alloy steel produced is poor, lack of pinning of the second phase particles to the grains, the quality is difficult to guarantee, the process controllability is poor, the production process control requirements are high, and the control is difficult and other defects

[0016] Due to the high melting temperature of die steel, the difficulty of uniform dispersion technology in steel after nanoparticles are added to steel, etc., seriously restricts the development and application of metal matrix nanocomposites, resulting in some metal matrix nanocomposites developed at home and abroad. The preparation process of metal-based nanocomposites is still in the experimental stage, so that the current research on metal-based nanocomposites is still vacant, at least no products have been formed yet.