Preparation and repairing methods of molten aluminum corrosive wear resistant rotor for molten aluminum degassing

Abstract

The invention relates to a preparation method of a molten aluminum corrosive wear resistant rotor for molten aluminum degassing. The preparation method comprises the following steps: thermal treating, machining, oil removal, surface coating, surface roughening, thermal-spraying of a bonding layer, and thermal-spraying of a ceramic layer. The invention further relates to a repairing method of the molten aluminum corrosive wear resistant rotor for molten aluminum degassing, the repairing method comprises the following steps: grinding and polishing the surface, removing oil, coating the surface, roughening the surface, thermal-spraying the bonding layer and thermal-spraying the ceramic layer; the rotor matrix in the invention is good in machinability, the prepared coatings are high in bonding strength with the matrix material, have high boning strength, low porosity, and non-wetting with the molten aluminum, excellent molten aluminum corrosion and abrasion resistance; therefore, the rotor is long in service life, and the rotor with coating failure can be repaired and reused, the use cost is reduced, and the rotor can be widely used for degassing purifying equipment in an aluminum smelting process.

Description

technical field [0001] The invention relates to the preparation and repair method of a liquid aluminum degassing rotor resistant to aluminum liquid corrosion and wear. Background technique [0002] In the liquid aluminum purification device, the rotor of the rotating nozzle plays a very important role. During the refining process of aluminum, the rotor rotates at a high speed, and argon or nitrogen is sprayed into the molten aluminum through the rotor rod and the nozzle to remove the hydrogen and oxides contained in the molten aluminum, thereby purifying the molten aluminum. The rotor needs to be non-wetting and non-polluting to the aluminum liquid, and has a certain strength and hardness, high temperature resistance and thermal shock resistance, and is easy to process, connect, install and seal. The commonly used materials are nitride ceramics, pure graphite, etc. Nitride ceramics have high hardness and brittleness after sintering, and are not easy to process; although pur...

AI Technical Summary

Problems solved by technology

The commonly used materials are nitride ceramics, pure graphite, etc. Nitride ceramics have high hardness and brittleness after sintering, and are not easy to process; although pure graphite has good machinability, graphite will oxidize when it exceeds 600 ° C, and aluminum liquid During refining, the temperature of the aluminum liquid in the degassing box can reach about 900°C. In addition, the rotor generally rotates at a high speed of 300 rpm to 700 rpm. The aluminum liquid will strongly scour and wear the graphite rotor, especially in The surface of the molten aluminum gradually becomes thinner and is broken and scrapped, so the life of the graphite rotor is short and the cost of use is high

Although coating the graphite rotor or installing a casing can slow down the wear and corrosion of the molten aluminum, the coating process is complicated and the mechanical properties of the coating layer are poor. The casing method increases the complexity and cost of the workpiece

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