Lost foam casting-penetrating method for improving heat resistance of gray cast-iron based casting surface

Abstract

The invention discloses a lost foam casting-penetrating method for improving heat resistance of gray cast-iron based casting surface, aiming at forming a heat-resistant alloy layer on the casting surface. The steps of the method comprises: 1) the preparation of a lost foam model, and the design and mixture of all composites of casting-penetrating coating layer are carried out; that is, polystyrene foam plastics are used for processing the lost foam model which has the same shape with the casting needed; the composites and content of the casting coating layer are designed, weighted and evenly mixed. 2) the casting coating-penetrating layer and a coating layer are coated; that is, caking agents are added in the composites of the mixed casting-penetrating coating layer, then is mixed to be pasty; the pasty matter is uniformly coated on the corresponding surface of the lost foam model, the surface is leveled by brushing absolute ethyl alcohol and is baked in an electric stove. The surface of the casting-penetrating coating layer is coated into the coating layer after the coating is dried on the lost foam model by adopting a brushing, soaking, dripping or spraying method, and then is baked in the electric stove. 3) molding is carried out. 4) casting is carried out; that is, the casting temperature of molten iron of the gray casting iron is 1400-1450 DEG. C, after being casted for four hours, box-opening, cooling, sand shaking-out and cleaning are carried out.

Description

technical field [0001] The invention relates to a casting method of castings made of gray cast iron, more specifically, the invention relates to a lost foam casting infiltration method for improving the surface heat resistance of gray cast iron-based castings. Background technique [0002] Surface processing technology is a very broad technical field and a technical basis with extremely high use value. Surface alloying of castings is one of them, such as the cast infiltration method (cast infiltration process) of casting surface alloying. The casting infiltration method can be divided into: [0003] 1. Ordinary cast infiltration method [0004] In the initial stage of the development of the casting infiltration method, the use of alloy powder-based coatings on the surface of the casting mold cavity, the use of the infiltration ability of liquid metal, the waste heat of molten metal, and the metallurgical interaction between the molten metal and the metal powder, The alloy...

AI Technical Summary

Problems solved by technology

[0009] The lost foam casting infiltration method has been widely used in production. Many manufacturers use this technology to produce castings with wear-resistant and corrosion-resistant surfaces, and the technology is quite mature. However, castings are not only subject to wear during use, In addition to corrosion, when working in a long-term high-temperature environment, the surface will be damaged or invalid due to oxidation. Therefore, it is particularly important to study how to improve the heat resistance of the casting surface

At present, most of the heat-resistant alloying elements are coated on the surface of the casting by melting, surfacing, thermal spraying, or using high-energy beam heat source coating and melting on the surface of the formed casting to form a heat-resistant alloy. surface to improve the service life of castings, but the equipment used by these technologies is complex, the production cost is high, and the environmental pollution is relatively large

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