Casting method for producing steel casting through precoated sand

Abstract

The invention provides a casting method for producing a steel casting through precoated sand. The casting method includes the steps that a casting technology is designed; a developing mold is designed; the mold is assembled; a sand shell and a sand core are manufactured; and mold assembling, casting molding and aftertreatment processes are carried out. The sand shell and the sand core are produced by jetting the precoated sand through an automatic core shooter, so that pollution is avoided, efficiency is high, mold lifting is easy, the surface of a sand mold obtained after mold lifting is smooth, the size accuracy is high, the pressure during casting is high, the filling force is large, and the produced casting is high in density. The product manufactured according to the casting method can meet the quality requirement of various ship parts, and is suitable for volume production.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a casting method for producing steel castings by using coated sand. Background technique [0002] The production of marine parts is characterized by large batches, short procurement cycles and high precision requirements. At present, the production of marine parts adopts investment casting (lost wax precision casting) process. Sanding, cutting, rough grinding, fine grinding, shot blasting, and other processes. Lost wax casting is to use wax to make a wax mold of the part to be cast, and then coat the wax mold with mud, which is the mud mold. After the clay mold is dried, it is fired into a pottery mold. Once fired, all the wax molds are melted and lost, leaving only the pottery molds. Generally, when the mud mold is made, the sprue is left, and then the molten metal is poured into the sprue, and after cooling, the required parts are made. [0003] The above-mentioned inve...

AI Technical Summary

Problems solved by technology

[0003] The above-mentioned investment casting process mainly has the following problems: 1. The cost is high. At present, except for the mold-making wax material of investment casting, which can be recycled, the rest, such as sand, quartz powder, water glass, refractory mud, etc. used for shell making, are difficult to recycle, which increases the cost. The use of new sand increases production costs

②Environmental pollution is serious. Ammonium chloride is used as a hardening agent in the shell making of investment casting. The ammonia gas volatilized by ammonium chloride will affect the environment and cause harm to the health of employees. The general manufacturer of mold shell roasting uses Coal is used as a heat source. Due to the high cost of gas purification and treatment equipment, it directly pollutes the atmosphere. Formal enterprises use electricity or natural gas as a heat source, but a large amount of harmful gas will still be produced when the mold shell is roasted.

The process is long and the quality is difficult to control, resulting in long lead times

[0004] As mentioned above, the shortcomings of existing casting technology make it difficult for investment casting to cast steel castings with fine dimensional accuracy (marine parts, lashing parts) in large quantities, at low cost, with high efficiency and high pass rate.