Optimized technology for manufacturing water glass shell

Abstract

The invention relates to the steel casting industry, in particular to an optimized technology for manufacturing a water glass shell. The Be' of water glass ranges from 39 to 41, the modulus M of the water glass ranges from 3.1 to 3.4, and the density rho of the water glass ranges from 1.33 g / cm<3> to 1.368 g / cm<3>. A first face layer is formed by a mixture comprising 85% to 92% of 200-mesh quartz powder and 8% to 15% of 70-mesh-to-140-mesh quartz sand, the powder-liquid ratio n is 1.25 to 1.40:1, the viscosity measured through a phi6 flow cup ranges from 20 S to 60 S, the thickness of a coating ranges from 0.28 mm to 0.42 mm, and 40 / 70-mesh quartz sand is scattered. A second face layer is formed by 200-mesh quartz powder, the powder-liquid ratio n is 0.8 to 1.15:1, the viscosity measured through a phi6 flow cup ranges from 20 S to 60 S, the thickness of a coating ranges from 0.22 mm to 0.26 mm, 20 / 40-mesh quartz sand is scattered, and hardening is carried out through ammonium chloride. A transition layer is formed by mullite powder, the viscosity measured through a phi8 flow cup ranges from 8 S to 25 S, and 16 / 30-mesh mullite sand is scattered. Reinforcing layers are formed by 200-mesh mullite powder, the powder-liquid ratio n is 1.10 to 1.75:1, the viscosity, measured through a phi8 flow cup, of the first layer ranges from 30 S to 40 S, the viscosity, measured through the phi8 flow cup, of the second layer ranges from 50 S to 65 S, the viscosity, measured through the phi8 flow cup, of the third layer ranges from 70 S to 85 S, the viscosity, measured through the phi8 flow cup, of the fourth layer and the other layers ranges from 90 S to 120 S, 10 / 20-mesh mullite sand is scattered, and hardening is carried out through aluminum chloride. The manufactured shell can meet the requirements for cast fine steel castings.

Description

technical field [0001] The invention relates to the steel casting industry, and provides an optimized process for making water glass shells for investment casting shells. The application of the process can not only improve the quality of the shells, reduce the loss in the process, but also ensure precision castings accuracy requirements. Background technique [0002] Sodium silicate shell is rich in raw and auxiliary materials and low in manufacturing cost. It is a traditional process for more than 50 years and is widely used in investment casting steel castings that do not require high geometric dimensions, shape tolerances, and surface accuracy. Many companies in the same industry use different raw and auxiliary materials, coating formulas, and shell-making methods. Usually, "teachers lead apprentices" to make shells based on experience. There are no strict process specifications, and shell delamination, cracks, and pores sometimes occur. , sand inclusions, insufficient h...

AI Technical Summary

Problems solved by technology

The cast castings cannot guarantee the dimensional accuracy and surface accuracy requirements

The grinding workload in the subsequent process is large, the production cycle is long, and the cost is high. The shell is not suitable for casting large-scale pump and valve steel castings.