Concreting system for thin-walled cylindrical part and precision casting formation method

Abstract

The invention discloses a concreting system for a thin-walled cylindrical part and a precision casting formation method. The concreting system comprises a wax tree formed by welding a sprue cup, a straight sprue, a horizontal sprue, an inner sprue and a casting together in sequence, wherein the wax tree is coated with a mould case. The precision casting formation method comprises the following steps: forming the mould case without a parting surface, coating the mould case, preheating the mould case, smelting and pouring, cleaning the casting, performing heat treatment, and the like. The precision casting formation method can replace the conventional widely-applied centrifugal casting forming method, mother alloy can be remarkably saved, the yield can be remarkably improved, the harsh requirements on equipment, environment and personnel can be reduced, the processing amount can be reduced, the cost is only 60% of that of the centrifugal casting, and as Stellite neck bush is high in consumption and multiple in variety each year, very considerable economic benefits are achieved.

Description

technical field [0001] The invention belongs to the precision casting of Stellite alloy, in particular to the precision casting forming method of a wear-resistant Stellite inner bush for a valve core and a valve stem of a steam turbine. Background technique [0002] The steam turbine spool parts require that the sealing surface has a certain hardness to ensure its wear resistance and prolong the service life of the parts. For this reason, the methods commonly used at present are 1) surface nitriding treatment; 2) adopting the process of plasma spray welding to surfacing Stellite alloy on the workpiece surface. 3) After the overall inner lining of Stellite alloy is interference-fitted with the outer sleeve of the sleeve, the end faces are sealed and welded to achieve the functions of sealing and wear resistance. [0003] Among the above-mentioned several processes, the surface nitriding treatment process is simple, but the sealing performance and wear resistance are relative...

AI Technical Summary

Problems solved by technology

[0003] Among the above several processes, the surface nitriding process is simple, but the sealing performance and wear resistance are relatively poor

Plasma spray welding technology needs to design and manufacture a series of high-performance inner hole plasma spray guns according to different inner hole diameters, and has strict requirements on the operator's technology and the surrounding environment, the process is complicated, and the yield is very low.

[0004] The one that is developing well now is the integral Stellite inner bushing made by the centrifugal casting method. Only a few manufacturers have the production capacity of this product, and the price is expensive.

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