Method for manufacturing vein-proof sand core

Abstract

The invention relates to a method for manufacturing a vein-proof sand core. The vein-proof sand core specifically comprises the following raw materials of, in percentage by weight, 94-95 of quartz sand, 2.2-3.25 of phenolic resin, 0.5-1 of a coating, 1-2 of a vein-proof agent and 0.5-1.3 of an auxiliary material; The vein-proof agent comprises the components of, in percentage by weight, 2-3 of alpha modified starch, 36-40 of iron oxide powder, 20-25 of iron powder, 25-30 of boric acid powder, 1-3%of titanium powder, 2-4 of coke powder and 0.5-2 of rare earth powder; and the process for manufacturing the vein-proof sand core comprises the steps of sand mixing, core box filling, heating and curing, box opening and surface finishing, coating mixing, paint coating and drying and grinding. The vein-proof sand core is used for preventing veining defects from appearing on the inner surface of a casting cavity and affecting flowing of gas or a liquid in the cavity.

Description

technical field [0001] The invention belongs to the technical field of anti-veining of castings, and in particular relates to a method for manufacturing an anti-veining sand core. Background technique [0002] In casting production, the sand core and the cavity are enclosed to form a cavity that matches the shape of the casting, and the high-temperature molten iron is filled into the cavity, and the casting is formed after solidification and cooling. In the production process of gasoline engine cylinder block and cylinder head, exhaust pipe, automobile exhaust pipe and turbocharger casing, etc., which require gas or liquid, because the inner surface of the cavity of this part cannot be machined, the part The surface quality of the cavity of the casting of the part is high. In the process of casting production, reduce or prevent casting defects from appearing on the surface of the inner cavity of this part of the casting, affecting the flow of gas or liquid in this part of t...

AI Technical Summary

Problems solved by technology

The surface layer of the sand core prepared by this method has the characteristics of easy collapse, poor plasticity and yield. When the sand core is used to produce castings, when the sand core encounters high-temperature molten iron, the phase change of the quartz sand in the sand core is very easy to form sand. Formation of micro-cracks on the core surface, causing veining defects on the inner surface of the casting cavity

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