Manufacturing process of pump body casting of super duplex stainless steel centrifugal pump

Abstract

The invention provides a manufacturing process of a pump body casting of a super duplex stainless steel centrifugal pump. The manufacturing process comprises steps of sand mould prefabricating, material smelting, casting, sand shakeout and heat treatment, wherein a runner core in a sand mould is composed of chromite furan resin sand of which the outer layer is filled with quartz furan resin sand;in material smelting, super duplex stainless steel material ZG00Cr25Ni7Mo4N is used, the chemical composition, ferrite content and PREN (Pitting Resistance Equivalent) value of molten steel are undercontrol and the casting temperature is from 1540 DEG C to1560 DEG C; after sand shakeout, forced air cooling is carried out, spray cooling is further carried out on the thick and large part of the casting, and after a casting system and a dead head are removed, the heat treatment is carried out. The pump body casting of a super duplex stainless steel centrifugal pump, which is manufactured by using the manufacturing method, has the advantages that the manufacturing and maintenance cost is reduced, abrasion resistance and pitting resistance are improved and the service life is prolonged.

Description

technical field [0001] The invention relates to a casting manufacturing process of a super duplex stainless steel centrifugal pump body, and belongs to the technical field of fluid conveying equipment casting. Background technique [0002] The third generation of super duplex stainless steel is a new type of material. SAF2507, which was successfully developed in Sweden, is a typical representative. It is mainly used in the forging industry. It has ultra-low carbon (≤0.03%), PREN greater than 40, high chromium (≥25%), and high molybdenum. (≥4%), high nitrogen (0.1-0.3%), has high corrosion resistance and wear resistance, and has gradually become the material used for various equipment in seawater or chlorinated corrosive media. [0003] At present, the reason why super duplex stainless steel can not be quickly applied and promoted in castings is that its ferrite content is too high, and it is easy to precipitate brittleness and produce casting cracks. However, in order to ens...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to address the above problems, to provide a super duplex stainless steel centrifugal pump body casting manufacturing process, to solve the problem of super duplex stainless steel pump body castings due to high ferrite content, complex casting structure, and large wall thickness differences. Uneven cooling, brittle phase precipitation temperature range is large, which leads to cracks, sand sticking and other problems, and obtains a high dimensional accuracy, compact internal structure, no sand sticking in the inner cavity of the flow channel, pitting corrosion resistance, wear resistance, reliable operation, and high efficiency. High-quality, long-life super duplex stainless steel centrifugal pump body castings to replace traditional materials that rely on coatings and cathodic protection to improve corrosion performance