Casting method for impeller made of super duplex stainless steel 5A material

Abstract

The invention provides a casting method for an impeller made of a super duplex stainless steel 5A material. The method comprises the steps of preparation of a casting mould and a sand core, specifically, the casting mould and the sand core are prepared in the manner that alkaline phenolic resin is added to crude sand, the casting mould is provided with an impeller cavity for storing the sand core, and a dead head is internally provided with a ceramic foam filter; casting and pouring; and sand shakeout and heat treatment of a heat-filling furnace, and an impeller finished product is obtained. The temperature ranges of precipitation of brittle phases including Eta, Chi and Sigma can be avoided, precipitation of the brittle phases by an impeller casting structure is avoided, crack defects of an impeller casting are overcome fundamentally, density of the casting structure can also be guaranteed, and the yield rate of a casting finished product can be increased to 96% or above; and meanwhile, the casting production cost is greatly lowered as the technological yield is increased, and the heat-filling furnace process is implemented.

Description

technical field [0001] The invention belongs to the application field of casting technology, and in particular relates to a casting method of an impeller made of super duplex stainless steel 5A. Background technique [0002] As a key part of the pump, the impeller is directly related to the working efficiency of the pump. Its space surface is complex, and the precision of the size and blade shape is high, so it needs to carry out double-sided dynamic and static balance testing. At the same time, as the power part of the pump, the impeller also bears Fluid corrosion, erosion corrosion and cavitation corrosion, etc., require materials to have certain corrosion resistance, compact structure, and no casting defects. [0003] ASTM A890 5A material is the third generation duplex stainless steel, its composition range is C≤0.030%, Si≤1.0%, Mn≤1.5%, P≤0.040%, S≤0.040%, Cr: 24.0~26.0%, Ni: 6.0-8.0%, Mo: 4.0-5.0%, N: 0.10-0.30%. Compared with ordinary duplex stainless steel, its sal...

AI Technical Summary

Problems solved by technology

The disadvantage is that the temperature of the molten metal at the bottom is high after filling the mold, which is not conducive to shrinkage; the gating system consumes a lot of molten metal, and the process yield is low; the slag and gas gathering effect of the gating system is poor, and the castings are prone to sand, slag and pores Defects; when the pouring temperature is low, it is easy to form cold shut defects

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