Method for preparing oxygen-rich full mold in pre-foaming stage based on lost foam mold

Abstract

The invention discloses a preparation method of an oxygen-enriched lost foam in the pre-foaming stage based on a foam white mold. stage, using intermittent pre-expansion machine or continuous pre-expansion machine to expand and infiltrate external oxygen-enriched air into the foam cavity of foam white mold beads, so that the oxygen volume content in the gas of the foam cavity is not less than 21%. On the one hand, the present invention promotes the combustion and gasification of carbon atoms in the white mold, and reduces the residual solid products produced by foam pyrolysis; on the other hand, it promotes the oxygen-rich combustion of the white mold organic matter, and makes up for the heat absorption and cooling of the white mold pyrolysis process; and more Active oxygen atoms can promote the cracking degree and cracking speed of white mold.

Description

technical field [0001] The invention belongs to the technical field of lost foam casting, and in particular relates to a method for preparing an oxygen-enriched lost foam in a pre-foaming stage based on a foam white mold. Background technique [0002] Lost foam casting is an advanced technology with nearly no margin and precise molding. It conforms to the general trend of casting technology development and has broad development prospects. Its superiority is beyond doubt. In the lost foam process technology, the development of the pattern material and the pattern preparation process are particularly important: first of all, only the pattern material can have the lost foam (real) casting technology, and the development of the lost foam casting technology requires a pattern with better performance materials, and their preparation processes. [0003] At present, the raw materials used in the foam pattern used in lost foam casting are expandable resin beads. There are three main...

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: 1) The foam pattern prepared by various types of expandable resin beads, such as EPS (expandable polystyrene resin beads), EPMMA (expandable polymethyl methacrylate resin beads), STMMA (expandable methyl methacrylate and styrene copolymer resin beads), etc., all have carbon residues caused by high-temperature pyrolysis solid products to varying degrees. Surface defects such as black and slag inclusions

2) For the foam pattern prepared by various types of expandable resin beads, at high pouring temperature, the pyrolysis process needs to absorb a large amount of heat, causing the front-end metal liquid to cool down rapidly, resulting in a decrease in the fluidity of the front-end of casting filling, which is prone to cold Moreover, as the temperature of the front end of the molten metal drops, it is easy to cause insufficient pyrolysis and gasification of the foam pattern, and the increase of liquid and solid residues, together with the supercooled molten metal, forms the unique bean curd slag cold insulation phenomenon of lost foam casting