High-performance wet green sand for steel casting and preparing method thereof

Abstract

The invention discloses high-performance wet green sand for a steel casting and a preparing method of the high-performance wet green sand. High-performance wet green sand is composed, by weight, of 40-60 parts of zircon sand, 15-20 parts of sea mud, 10-15 parts of ardealite, 25-35 parts of diopside, 20-30 parts of polyphenyl granule, 5-10 parts of sodium fluoroaluminate, 15-20 parts of coconut shell powder, 10-15 parts of crushed brick powder, 4-8 parts of hydroxypropl xanthan gum, 3-6 parts of sulfonated asphalt powder, 5-10 parts of bitter ling soil, 2-4 parts of calcium sulfite, 3-5 parts of poly aluminum chloride, 4-6 parts of polyoxyethylene, 2.5-4.5 parts of sodium hexametaphosphate, 5-10 parts of modified kaolin and a proper amount of water. The wet green sand is good in comprehensive performance, has the high green compression strength, the high compaction rate and the low thermal expansivity, also has the good high-temperature resistance, ventilating performance and fluidity and can effectively overcome the defects that air holes, scabbing, sand clamping, sand holes and the like can happen on the steel casting, the surface quality of the steel casting is improved, the finished product rate of the steel casting is increased, and the high-performance wet green sand has important economic benefits.

Description

technical field [0001] The invention relates to high-performance green sand for steel castings and a preparation method thereof, belonging to the technical field of molding sand. Background technique [0002] The wet casting method has many advantages: no drying is required, drying equipment and fuel can be saved, the service life of the sand box and molding sand can be extended, the working conditions of workers can be improved, the process is simple, the productivity is high, the production cycle is short, it is convenient to organize flow production, and it is easy to Realize the mechanization and automation of the production process. Therefore, wet casting is widely used in steel casting. [0003] Although the wet type has many advantages compared with the dry type, it has not been dried. Therefore, when the high-temperature molten steel is poured, the interface reaction between the metal and the wet type is relatively strong, and the casting is prone to some defects. ...

AI Technical Summary

Problems solved by technology

[0004] (1) The water content of green sand is much higher than that of dry sand. When it meets molten steel with a temperature as high as 1500°C, the water evaporates and the volume suddenly expands, which easily causes pore defects in steel castings.

[0005] (2) During pouring, the moisture on the surface of the wet mold cavity migrates to the inside of the sand mold due to the high-temperature baking of the molten steel, forming a moisture condensation area with low strength, which easily delaminates the surface of the mold cavity and causes steel castings Defects such as scars and sand inclusions;

[0006] (3) The wet strength of clay sand is lower than the dry strength, and it is easy to drop sand under the action of external force, forming sand holes in the casting; and the sand particles on the wall of the gating system are easy to fall off under the scouring action of the metal liquid flow, and are brought into the casting by the metal liquid formation of trachoma