Precision casting process of large casting

Abstract

The invention discloses a precision casting process of a large casting. The precision casting process comprises the following steps: preparing a wax mold, and finishing; preparing a shell mold sand mold; dewaxing; roasting a shell mold; fabricating the sand mold; venting; casting to obtain the casting. Respective advantages of precision casting and sand casting processes are combined, and the precision casting technique of the large casting is achieved. The shell mold disclosed by the invention is steeped and adhered by slurry which is specially prepared for a plurality of times, is subjected to manual sand floating, and is subjected to segmented heating roasting, and a high-strength shell mold is formed, so as to achieve the strength requirements of casting the large casting. Mixed sand with alkaline phenolic resin is injected into a sand box, so that the precision casting process is relatively good in strength and relatively stable, the surface accuracy of the casting can be further improved, and the quality of the casting is improved.

Description

technical field [0001] The invention relates to a metal casting method, in particular to a precision casting process for large castings. Background technique [0002] At present, the commonly used precision casting method usually obtains castings from mold making, wax mold making, shell mold making, roasting, and pouring metal. However, this process is generally applied to casting small castings less than 150Kg. For large castings larger than 150Kg, due to the large size and volume of the casting, the strength of the shell mold cannot be guaranteed, and the quality of the casting is difficult to obtain. Therefore, it is generally difficult for large castings to achieve precision casting or to achieve precision casting but cannot operate normally. Therefore, in the industry, large or super large castings are generally completed by sand casting, but sand casting cannot achieve the dimensional accuracy of precision casting, and The surface quality of the casting is poor and th...

AI Technical Summary

Problems solved by technology

However, this process is generally applied to casting small castings less than 150Kg. For large castings larger than 150Kg, due to the large size and volume of the casting, the strength of the shell mold cannot be guaranteed, and the quality of the casting is difficult to obtain. Therefore, it is generally difficult for large castings to achieve precision casting or to achieve precision casting but cannot operate normally. Therefore, in the industry, large or super large castings are generally completed by sand casting, but sand casting cannot achieve the dimensional accuracy of precision casting, and Poor surface quality and low precision of castings