The casting sand is going on
3, prevention measures(1) to improve the strength of sand mold (core), especially surface strength, high temperature strength, refractoriness, compact, better coating, good core coating and parting surface coating.(2) mould and box can prevent damage;(3) the core should have clearance.
2, causes(1) sand mold (core) strength is not high, when the box a little reason will fall off.(2) the strength of sand mould (core) is not high, it can not stand the erosion of molten steel.(3) box sand mould (core) crush.(4) high strength under high temperature, warpage, deformation and protuberance into the cast steel under the action of high temperature molten steel.(5) the floating sand in the air hole of the sand mold falls, especially when the floating sand falls in the casting, and the floating sand on the surface of the sand mold is easy to fall through the air vent.(6) when the box is closed, the surface of the mold cavity and the surface of the sand core are not cleaned, and the sand (core) surface has floating sand and so on.
Dispersed sand inclusion is common on the surface and subcutaneous of steel castings, often concentrated on the outer surface of the upper box and the inner surface of the lower case, and a few of them are inside the cast steel parts.
