A casting method for hollow turbine guide vanes

Abstract

The invention provides a pouring method of a hollow turbine guide vane. The pouring method comprises the following steps: (1) manufacturing a wax mold combination; (2) carrying out shell making on the wax mold combination to obtain a hollow turbine guide vane shell; (3) covering one layer of ceramic heat-preservation cotton on a shell vane body part; covering two layers of ceramic cotton on the whole shell; and putting the treated shell into a roasting furnace and carrying out casting, wherein in a casting process, the temperature of casting the shell is 1065-1085 DEG C and the pouring temperature is 1460-1480 DEG C. According to the pouring method of the hollow turbine guide vane, a pouring system of the hollow turbine guide vane is not changed and the shell temperature and the pouring temperature are adjusted so that the casting temperature field is changed; the two layers of ceramic cotton on the whole body and one layer of the ceramic heat-preservation cotton on the vane body part are matched so that after the temperature of the whole shell is improved, the temperature field is uniform, the casting stress is eliminated and the casting temperature is reduced; and furthermore, the temperature field on a casting vane body and an edge plate keeps uniform, the shell is effectively insulated and the casting stress is eliminated.

Description

technical field [0001] The invention relates to the technical field of precision casting, in particular to a pouring method for a hollow turbine guide vane. Background technique [0002] In the prior art, investment casting without margin is currently the best method for manufacturing turbine blades. Its technological process mainly includes the design and manufacture of core molds, pressed cores, design and manufacture of wax molds, assembly and injection of wax, slurry shell making, drying shells, dewaxing, sintering, pouring metal, shelling and core removal , Laser drilling and other links. The hollow turbine guide vane adopts the combination of top injection and bottom injection to produce this type of casting. After the wax model is made, the entire shell is wrapped with a layer of ceramic wool, and the casting is carried out in a set temperature field. Due to the limitation of the shell during casting, , It is necessary to limit the temperature of the mold shell and ...

AI Technical Summary

Problems solved by technology

The hollow turbine guide vane adopts the combination of top injection and bottom injection to produce this type of casting. After the wax model is made, the entire shell is wrapped with a layer of ceramic wool, and the casting is carried out in a set temperature field. Due to the limitation of the shell during casting, , it is necessary to limit the temperature of the mold shell and increase the pouring temperature. Although this process scheme can reduce the porosity of the casting and reduce the number of hot cracks in the casting, it cannot completely eliminate the hot crack and loose defects of the casting.

At the same time, in the combination of top injection and bottom injection, the problem of thermal cracking at the junction R of the hollow turbine guide vane and the airfoil cannot be solved, and the scrap rate is high

And in the process of slurry coating and shell making, the stress is not uniform, and hot cracking defects are prone to occur

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