Method for remanufacturing blast furnace copper air port

Abstract

The invention provides a method for remanufacturing a blast furnace copper air port, and belongs to the technical field of metal surface engineering. According to the method, a cold metal transfer (CMT) welding technology is adopted to repair the outer surface and inner wall of the copper air port. The welding process is low in thermal input and splashing amount, and it is ensured that the remanufactured copper air port does not lose effect because of thermal deformation. Moreover, a formed CMT welding layer can prolong the service life of the blast furnace copper air port. The method overcomes the problems that workpiece thermal deformation happens very easily because of conventional surface remanufacturing technologies such as submerged arc surfacing, open arc surfacing, plasma arc cladding and spray welding. The remanufacturing method is low in cost and high in efficiency, and full-automatic production can be realized. Results of the embodiment show that the roughness Ra of the remanufactured copper air port ranges from 0.4 and 0.8, and the service life can reach over 1.5 times of that of a new copper air port.

Description

technical field [0001] The invention relates to the technical field of metal surface engineering, in particular to a method for remanufacturing copper tuyeres of blast furnaces. Background technique [0002] Blast furnace copper tuyere is an important equipment necessary for blast furnace ironmaking air supply. The copper tuyere is usually installed in the furnace wall between the bosh and the furnace bottom, and the front end extends into the furnace by about 400-600mm. The theoretical combustion temperature in the swirl area at the front end of the copper tuyere is as high as 2450°C, and the temperature of the hot air sent in the copper tuyere can reach 1300°C; the part of the copper tuyere extending into the furnace is directly subjected to the thermal shock of liquid slag iron and the wear of the falling hot material; When the air is supplied, the inner wall of the copper tuyere is eroded by the pulverized coal. Therefore, the working environment of the blast furnace c...

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Problems solved by technology

Therefore, the working environment of the blast furnace copper tuyere is very harsh, and the outer surface and inner wall of the blast furnace copper tuyere are prone to wear

[0003] The cost of blast furnace copper tuyere is relatively high, and the price is very expensive. If the damaged blast furnace copper tuyere is directly scrapped, it is not environmentally friendly and will cause a serious waste of resources

At present, there is no general process method for the maintenance of the outer surface and inner wall of the blast furnace copper tuyere. The inner cavity of the blast furnace copper tuyere has a circulating water channel. At the same time, the traditional copper welding process is difficult to eliminate defects such as large thermal deformation and welding air hole inclusions, similar to plasma Welding, gas shielded welding, surfacing welding and other processes have the disadvantage of large heat input, resulting in the repaired copper tuyeres being scrapped due to large thermal deformation and unable to continue to be used; at the same time, since the repair of the inner wall of the copper tuyere belongs to the repair of the inner hole, other Such as spraying, spray welding and other technological means, it is impossible to repair the inner wall of the copper tuyere

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