The traditional sand casting method is generally used in the production of cast iron water meter, which has complex process, high labor intensity, poor working environment, and produces a large amount of old sand with sand core, which seriously affects the environment. Sand casting of water meter shell is a casting process with high investment, high consumption, high pollution, low output and low benefit.
Lost Foam Casting (EPC) is a solid mold casting with non bonding agent dry sand combined with vacuum pumping technology. It is considered to be the most likely technology to achieve green casting in twenty-first Century. EPC process can produce castings with complex structure, high dimensional accuracy, low surface roughness and less machining allowance. It has the characteristics of high utilization rate of liquid metal, low environmental pollution and no need to take mold. It is a promising near net shape processing technology and cleaner production technology. It has successfully solved the problems of inflexible traditional sand casting production mode, complex molding process Problems such as high labor intensity and serious environmental pollution. Therefore, the research on the lost foam casting process of large-diameter thin-walled ductile iron watch case has great practical significance.
In order to produce thin-wall large diameter cast iron lost foam casting with water case, it is advisable to control the density of EPS forming material in the range of 23~25 g/L, pouring temperature at 1380~1420 C, negative pressure controlled at 0.06 ~ 0.07 MPa, adopting bottom pouring gating system, which is beneficial to smooth filling of alloy liquid and smooth discharge of slag after vaporization. It is not easy to produce liquid metal back injection during pouring, and a complete large-diameter thin-wall ductile iron watch case casting can be obtained.