Degassing and deoxidation process for cast aluminum bronze

Abstract

The invention discloses a degassing and deoxidation process for cast aluminum bronze. The process comprises the following steps of: 1) preheating a crucible; 2) charging according to a sequence, melting, adding an aluminum block, melting the aluminum block, adding an iron sheet, and stirring liquid state furnace charges by using a graphite rod after all furnace charges are melted into liquid; 3) heating to reach the temperature of between 1,250 and 1,300 DEG C; 4) adding zinc chloride for degassing; 5) adding rare-earth cerium for deoxidizing and degassing; 6) standing for 3 to 5 minutes, adding phosphor copper, refining and deoxidizing; and 7) standing for 3 to 5 minutes, slagging off, tapping, pouring a casting mould, and performing air cooling on a casting. By the degassing and deoxidation process, oxygen and hydrogen in molten aluminum bronze can be removed effectively, oxide impurities and air holes in the casting are reduced or eliminated, and the yield and the mechanical property of the casting are improved. The process is simple and low in production cost, energy consumption is not increased, copper liquid is high in flowability, and the mold filling capacity of the casting mould is facilitated.

Description

technical field [0001] The invention relates to a nonferrous metal casting process, in particular to a degassing and deoxidizing process in the aluminum bronze smelting process, and belongs to the technical field of nonferrous metal casting. Background technique [0002] The vapor pressure of the aluminum bronze liquid during casting is lower than that of brass and tin bronze, so it tends to absorb air greatly, and its castings are more likely to have pores and oxide impurities, which will reduce the mechanical properties of aluminum bronze castings until they are scrapped. [0003] During the smelting process of aluminum bronze alloy, under the condition of overheating, the copper liquid and water vapor will undergo the following reaction: 2Cu+H 2 O=Cu 2 O+2H and 2Al+3H 2 O=Al 2 o 3 +6H etc. The hydrogen produced by the above reaction dissolves into the copper liquid in the atomic state [H], and the generated Cu 2 O can be directly dissolved into the copper liquid, wh...

AI Technical Summary

Problems solved by technology

In addition, the commonly used covering agent for aluminum bronze is charcoal. However, the charcoal layer cannot prevent the hydrogen in the reducing furnace gas from dissolving into the copper liquid. Moreover, charcoal has the ability to absorb reducing gases, so it cannot be used in reducing atmospheres.

There are also broken glass 50% + sodium carbonate 50%, or broken glass 46% sodium decacarbonate 46% + calcium fluoride 8%. These covering agents are mostly acidic and only suitable for acidic or neutral linings.

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