The coated sand casting has a long history in the foundry field, and the output of the coated sand casting is also quite large. Application of ceramic foundry sand : coated sand can be made into mold and sand core. The mold or core of coated sand can be used together or together with other sand mold (core); It can be used not only in metal mold gravity casting or low pressure casting, but also in iron mold coated sand casting and centrifugal casting; It can be used not only in the production of cast iron and non-ferrous alloy castings, but also in the production of steel castings.
In view of the development of precision casting, it is a trend to produce steel castings by precision-casting in place of investment casting with precision-casting coated sand shell mold; Compared with the investment casting technology, it has great advantages, which are mainly embodied in the following aspects:
(1) Shortening production cycle by half, reducing labor intensity by 40% and increasing efficiency by 30%;
(2) Recycling the precoated sand after casting, eliminating dewaxing, wax treatment and roasting procedures, eliminating acid water and acid mist discharge, and reducing pollutant discharge by 80%;
(3) The casting deformation is small and the correction efficiency is increased by 50%; At the same time, the application of chills, the process yield increased by nearly 10%
(4) Compared with investment casting process, the comprehensive cost per ton casting can be reduced by 1000 ~ 1500 yuan.
Although the precision-casting coated sand shell mold technology has obvious advantages in the production of steel castings, there are also shortcomings.Too complex product structure, due to the large number of sand cores, results in a large amount of flash grinding; At the same time, there are still some odors after pouring, so the improvement of mold technology and the research and development of odorless coated sand will be the key direction.