Stainless steel impeller for phosphoric acid slurry pump and its preparation method

Abstract

The invention discloses a stainless steel impeller for a phosphoric acid slurry pump and its preparation method. The preparation method comprises the following steps: (1) smelting: adding raw materials into an intermediate-frequency furnace for smelting; (2) casting: putting round steel, a sand core and chill into a mold, winding the round steel with a gunpowder rope as the core bar of the sand core, kindling the gunpowder rope after completion of molding of the sand core, brushing the interior surface of the mold with an alcohol-based zircon powder paint, carrying out surface drying via a blowtorch, and then carrying out mold closing and casting; and (3) heat treatment: cooling a casting without a riser to a temperature of less than 300 DEG C, then putting the casting into a bogie-hearthresistance furnace for heat treatment, and carrying out cooling again so as to obtain a high-carbon high-chromium ferrite stainless steel impeller product. The high-carbon high-chromium ferrite stainless steel impeller prepared by using the method in the invention can effectively avoid the problem of casting cracks caused by easy precipitation of a brittle phase due to high ferrite content duringcasting.

Description

technical field [0001] The invention relates to the technical field of fluid conveying equipment casting, in particular to a stainless steel impeller for a phosphoric acid slurry pump and a preparation method thereof. Background technique [0002] Phosphoric acid slurry pump (also known as vortex pump) is a kind of vane pump. It is mainly composed of impeller, pump body and pump cover. The impeller is a disc, and the blades on the circumference are evenly arranged radially. An annular flow channel is formed between the pump body and the impeller, and the suction port and the discharge port are located on the outer circumference of the impeller. There is a partition between the suction port and the discharge port, thereby isolating the suction port and the discharge port. At present, the components of phosphoric acid slurry pumps are mostly made of low-carbon high-alloy or nickel-based alloy. [0003] The application number is 201310241030.7, which discloses a large-scale...

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Problems solved by technology

[0006] The purpose of the present invention is to solve the high-carbon and high-chromium ferritic stainless steel impeller in the prior art. Because its ferrite content is too high, it is easy to precipitate brittle phases and produce casting cracks, and it is difficult to produce castings with complex structures and large wall thickness differences. Provide a stainless steel impeller for phosphoric acid slurry pump and its preparation method, which can effectively solve the problem that the stainless steel impeller is prone to precipitate brittle phases and produce casting cracks due to the high ferrite content in the casting process

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