Preparation method of heat-resisting alloy sliding-block shell by investment casting

Abstract

The invention discloses a preparation method of a heat-resisting alloy sliding-block shell by investment casting. The preparation method is characterized in that: the method comprises a first step of preparing coating, wherein surface coating comprises silica sol and a refractory powder material is fused alumina; and transition layer coating and back layer coating comprise the silica sol and a refractory powder material is one selected from the fused quartz, kaolin clinker and bauxite clinker; a second step of coating a wax mould with the surface coating, scattering the sand material of the fused alumina, drying and repeating for 2 times; coating the surface layer with the transistion layer coating, scattering one of the fused quartz, the kaolin clinker and the bauxite clinker, drying, and repeating for 5 times; and finally coating with a back layer coating, scattering one of the fused alumina, the kaolin clinker and the bauxite clinker and drying; and a third step of dewaxing and calcinating; and the shell produced by the method has advantages of high room-temperature strength and high-temperature strength, good internal surface quality, high percent of pass, low production cost and good economic benefit.

Description

technical field [0001] The invention relates to the technical field of precision casting, in particular to a method for preparing an investment casting heat-resistant alloy slider mold shell. Background technique [0002] The slider of the pusher heating furnace in the rolling mill is a key component in the billet heating furnace, which plays a role in supporting and transferring the billet during the billet heating process. When its performance and metallurgical quality are fully guaranteed, the heating furnace can operate normally, effectively and economically, and ensure the quality of the rolled piece. At present, the slider is mainly made of austenitic heat-resistant steel (ZGCr28Ni48W5, ZGCr25Ni20, ZGCr25Ni35, ZGCr28Ni48W, ZGCo20, ZGCo40, ZGCo50, etc.), chromium-nickel superalloy to manufacture. Whether it is an ordinary welded slider or a card-type composite connection slider, the wall thickness of the part connected to the water pipe and the supporting part is ver...

AI Technical Summary

Problems solved by technology

However, due to the high viscosity of the binder on the one hand, the powder-to-liquid ratio of the prepared coating is very low, and the wettability with the mold is poor, the coating is not dense, and the surface of the casting produced is rough; on the other hand, it contains Na2O, The high-temperature strength of the mold shell is low, and the deformation resistance is poor. The surface of the produced casting is prone to defects such as orange peel and scarring, and the dimensional accuracy is low.

Although water glass binder has been used in domestic investment casting for more than 50 years, due to its own defects, even if the process is improved, it is difficult to solve the problem of uneven wall thickness in the production of sliders such as sliders. The problem of excessive roughness

At the same time, the shell-making process of investment casting silica sol and zirconium sand has also appeared in the prior art. Although the high-temperature strength of the shell blank is high and the quality has been improved, it also greatly increases the production cost.

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