Composite covering agent and use method thereof in production of cylinder cover casting

Abstract

The invention discloses a composite covering agent and a use method thereof in the production of a cylinder cover casting. The composite covering agent consists of a composite covering agent I and a composite covering agent II, wherein the composite covering agent I consists of the following components in parts by mass: 80-90 parts of SiC, 5-6 parts of recarbonizer and 5-15 parts of perlite; and the composite covering agent II consists of the components in parts by mass: 35-45 parts of inoculant and 55-65 parts of perlite. In the invention, the composite covering agents are adopted in the production of the cylinder cover casting to remove impurities and gas out of iron liquid so as to improve the metallurgical quality of the iron liquid; when heat preservation and collecting residues are carried out, the inoculation fade of the iron liquid is prevented, a favorable inoculation effect is obtained, thereby processing properties and mechanical properties of the cylinder cover are improved; meanwhile, a fine powder inoculant is turned into valuable materials and complies with the policies of recycling economy and low carbon economy. The invention has simple prescription, wide source materials which are easily obtained, simple use method, easy implementation, low production cost and favorable use effect.

Description

technical field [0001] The invention relates to a casting process, in particular to a method for using a composite covering agent in the production of cylinder head castings. Background technique [0002] The cylinder head is one of the main parts of the engine, which has a great influence on many technical parameters of the engine. Because the temperature of the engine changes sharply repeatedly during operation, the alternating thermal stress generated by the continuous expansion and contraction can easily lead to fatigue failure. Therefore, the requirements for the material and air tightness of the cylinder head are very high, and the casting process is difficult. At present, the smelting method usually adopted is open smelting, and the temperature of the molten iron is high, so the molten iron is easy to oxidize, resulting in slag inclusion, decarburization, and breeding recession, especially the slag inclusion, which causes the leakage of the inlet and exhaust passages...

AI Technical Summary

Problems solved by technology

At present, the smelting method usually adopted is open smelting, and the temperature of the molten iron is high, so the molten iron is easy to oxidize, resulting in slag inclusion, decarburization, and breeding recession, especially the slag inclusion, which causes the leakage of the inlet and exhaust passages of the cylinder head. Castings are scrapped, resulting in a very high scrap rate of products. Although there are many technological measures implemented to address this problem, most of them have little effect

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