Casting process for solving leakage and sand bonding

Abstract

The invention discloses a casting process for solving leakage and sand bonding. The casting process is characterized in that a special paint combination and an implementation sequence are used for coating a to-be-cast sand core; the paint combination is the combination of water-base graphite paint, alcohol-base oxygen-free paint and tellurium chilling paint; the viscosity and thickness as well as the coverage area of the paint are controlled so as to guarantee the stability of a coating. In real production, after the scheme is adopted, the leakage rate and the sand bonding rate can be effectively reduced, and the production efficiency can be greatly increased.

Description

technical field [0001] The invention relates to casting technology, in particular, a casting technology is proposed aiming at the common problems of leakage and sand sticking in casting. Background technique [0002] Leakage refers to the defects of castings that cause slight leakage due to micro-shrinkage cavities; micro-shrinkage cavities cannot be found by ordinary detection methods, and can only be displayed under very strict test conditions. The appearance of leakage will directly affect the performance of castings such as pressure resistance and sealing , the leakage of the engine crankcase blank will directly lead to the scrapping of the casting. [0003] At present, one of the common methods to solve the leakage is local quenching, using indirect chilled iron or chrome ore and other materials to increase the supercooling degree of the parts prone to leakage during solidification; the chilled iron is suitable for more regular parts, which is relatively Complex parts ...

AI Technical Summary

Problems solved by technology

[0002] Leakage refers to the defects of castings that cause slight leakage due to micro-shrinkage cavities; micro-shrinkage cavities cannot be found by ordinary detection methods, and can only be displayed under very strict test conditions. The appearance of leakage will directly affect the performance of castings such as pressure resistance and sealing , the leakage of the engine crankcase blank will directly lead to the scrapping of the casting

[0003] At present, one of the common methods to solve the leakage is local quenching, using indirect chilled iron or chrome ore and other materials to increase the supercooling degree of the parts prone to leakage during solidification; the chilled iron is suitable for more regular parts, which is relatively Complex parts are often treated with tellurium chilled paint. The main component of tellurium chilled paint is tellurium element. At high temperature, tellurium vapor is very easy to react with oxygen elements in silica sand or other paint layers, thus forming chemical sticky sand, causing the surface of castings to If the quality is unqualified, follow-up grinding and other processing procedures are required, which reduces production efficiency. If sand sticking occurs in a complex inner cavity, the casting will be scrapped because the sand sticking cannot be cleaned.

For example, the technical solution with the publication number CN103223457A discloses a water-based anti-sticking sand coating, which needs to be surface-dried under a high-temperature furnace gas at 200°C, which increases energy consumption and investment in foundry equipment, and the entire sand core is soaked. Coating, material consumption is large

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