A coating for lost foam casting and its application method

Abstract

The invention provides a coating for lost foam casting. The coating is prepared from the following raw materials by weight percent: 40%-47% of water glass with the modulus of 2.0-2.5, 52-59% of bauxite with the granularity of 62-74 microns or silica sand with the granularity of 62-74 microns, not more than 0.2% of emulsifier op-10, and 0.95% of phenolic resin liquid. The application method of the coating for lost foam casting comprises the following steps of: firstly, mixing the water glass, the emulsifier op-10 and the phenolic resin liquid together, and then adding the bauxite or the silica sand, and stirring all the materials evenly; then painting a lost foam module with the mixture pass by pass while drying; drying after the last pass of painting, and then cooling to room temperature; roasting the lost foam module; preserving heat at a temperature not lower than 400 DEG C; after burying the lost foam module in a box, carrying out slight vibration and then performing casting molding. The coating for lost foam casting can be used for solving the problems of recarburization, pore formation and slag inclusion in the lost foam casting process; the application time from coating painting to completion of roasting is reduced to not more than 32 hours from previously at least 48 hours; besides, the coating is excellent in high temperature resistance, high in shell mould strength and excellent in moulded shell collapsibility; the cost can be reduced by **-**.

Description

technical field [0001] The invention relates to a paint and a production method thereof, in particular to a paint for lost foam casting and a use method thereof. Background technique [0002] In the current general lost foam casting process, since the adhesive glue of the module and the module are organic matter, the amount of gas generated during pouring is large, so the gas permeability of the coating must be guaranteed under the condition that the product does not stick to sand. In order to achieve this Goals, there are too many things that need to be paid attention to during the formulation of the paint. Moreover, due to the national conditions of our country at this stage, there are few automatic equipment in the white area of ​​the lost foam casting workshop, and the painting of paint is basically in the stage of manual painting. The general casting process has the following disadvantages: [0003] 1. The cost of paint is high, and there are strict requirements on th...

AI Technical Summary

Problems solved by technology

[0003] 1. The cost of paint is high, and there are strict requirements on the thickness of paint for each product, which is not conducive to the operation of operators;

[0004] 2. Although the inside of the sand box is under negative pressure during pouring, it is still difficult for organic matter to dissipate after cracking and vaporizing, resulting in defects such as shrinkage cavities and slag inclusions;

[0005] 3. Because the foam module and organic glue contain a lot of carbon elements, the application of this process in the field of medium and low carbon steel is limited;

[0006] 4. Since the pyrolysis and vaporization of organic matter requires a lot of heat, it directly leads to an increase in pouring temperature, resulting in energy waste. At the same time, low-temperature pouring cannot be realized, and the internal structure of the finished product is not dense. There are many cases of fracture and failure during use, and severe wear and tear under the same conditions , can not meet the service life requirements

[0007] After retrieval, the Chinese Patent Publication No. is the patent literature of CN102672103A, which discloses a kind of coating composed of Guilin No. 5 and other refractory coatings. The disadvantage of its existence is that the production cycle is long