Method for reducing pouring temperature of iron-based surface composite material

Abstract

The invention relates to an iron-based composite material and especially relates to a method for reducing pouring temperature of iron-based surface composite material through heat release of thermit reaction, wherein the principle is as follows: triggering the thermit reaction by heating molten iron, counteracting the cooling effect of a ceramic particle pre-forming block on the molten iron through the heat release part of the thermit reaction, and simultaneously forming an alloy having the ingredients the same as that of a high-chromium iron substrate through the thermit reaction; in order to generate no effect on the distribution of the ceramic reinforcement particles and improve the wearing resistance of the hexagonal prism hole or honeycomb hole part, the reactant of the thermit reaction is processed to a cylindrical shape and is added in the hexagonal prism hole or honeycomb hole of the ceramic particle pre-forming block, the reactant powder is mixed and is pressed to the cylindrical shape so as to conveniently process and apply the cylindrical reactant, and the reactant powder is wrapped by an aluminum foil to prevent the cylinder from being broken and prevent the reactant powder from dropping.

Description

technical field [0001] The invention relates to an iron-based composite material, in particular to a method for reducing the pouring temperature of an iron-based surface composite material by utilizing the exothermic heat of the aluminothermic reaction. technical background [0002] High chromium cast iron has excellent wear resistance, and is widely used in wear-resistant parts such as grinding rollers, liners, and blow bars in cement and electric power industries. Parts fail rapidly and still cannot meet the requirements of users; therefore, particle-reinforced iron-based surface composites with better wear resistance have attracted more and more researchers and producers' attention. Studies have shown that the melt infiltration method is currently the One of the most suitable processes for preparing iron-based surface composite materials. However, due to the limitations of reinforcing materials and preparation processes, the thickness of the composite layer of iron-based ...

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Problems solved by technology

[0002] High chromium cast iron has excellent wear resistance and is widely used in wear-resistant parts such as grinding rollers, liners, and blow bars in industries such as cement and electric power. Under harsh abrasive conditions such as hard abrasives and high impact, high-chromium castings fail rapidly and cannot meet the requirements of users; therefore, particle-reinforced iron-based surface composites with better wear resistance have attracted more and more researchers. And producers are concerned, studies have shown that the melt infiltration method is currently one of the most suitable processes for preparing iron-based surface composites, but due to the limitations of reinforcing materials and preparation processes, the thickness of the composite layer of iron-based surface composites is often not More than 10mm, in many cases it is difficult to meet the requirements of the workpiece for the thickness of the wear-resistant layer

[0003] Patent CN102310183A discloses a high wear-resistant iron-based composite material and its preparation method. The preparation method includes the following steps: 1) Select large-sized fused zirconium corundum particles; 2) Prepare zirconium corundum particle ceramic blocks from the above-mentioned fused zirconia corundum particles, and cool them for use; 3) Place the above-mentioned zirconium corundum particle ceramic blocks on the top of the resin sand mold cavity for casting and infiltration process, and take out the box; 4) Heat treatment of the obtained zirconium corundum particles reinforced iron-based composite material, the inventive method is simple and convenient, and the thickness of the composite layer can be adjusted in a wide range; some researchers also proposed that ZTA with a particle size of 1-3 mm (ZrO2toughened Al2O3) ceramic particles are made into a honeycomb porous ceramic preform, and then cast high-chromium cast iron metal liquid casting Infiltrated ceramic preforms, successfully prepared ceramic particles reinforced high-chromium cast iron matrix composites (Casting, 2012, 61(2): 165.); however, the pouring temperature of the above two methods is lower than the usual pouring temperature of high-chromium cast iron workpieces The former is 1540~1590℃, and the latter is also 1450~1500℃; in these casting infiltration methods, due to the cooling effect of the preformed block of ceramic particles, it is difficult to achieve compounding at a lower pouring temperature, and higher On the one hand, the high pouring temperature reduces the performance of high chromium cast iron, and at the same time puts forward higher requirements for smelting equipment. Although preheating the sand mold can improve the composite effect to a certain extent, it is difficult to preheat the sand mold, and the effect is also low. Not obvious; therefore, it is urgent to take an effective method to reduce the pouring temperature of high chromium cast iron under the premise of ensuring the composite effect

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