Corrosion-resistant gray cast iron for water pump and production method thereof

Abstract

The invention discloses a corrosion-resistant gray cast iron for water pump and a production method thereof. The chemical composition of the corrosion-resistant gray cast iron for water pump is controlled by mass percentage as follows: carbon 2.6%-3.6%, silicon 1.2%-3.0%, manganese 0.4%- 1.2%, Phosphorus 0.02%~0.15%, Sulfur 0.05%~0.15%, Nickel 0.5%~2.0%, Chromium 0.5%~2.0%, Copper 0.5%~1.5%, Cobalt 0.5%~1.5%, Iron 84.4%~94.23 % and the inevitable impurity balance; the production method of corrosion-resistant gray cast iron for water pump includes: batching and smelting: batching according to the requirements of the target product composition, adding the main raw materials scrap steel, pig iron and return material into the intermediate frequency furnace, and then adding the ferromanganese , ferrosilicon, iron sulfide, ferrochromium, and alloys such as copper, cobalt and nickel are added to the intermediate frequency furnace; carburization treatment: when the molten iron is in a molten state, add a carburizer for carburization treatment, and the temperature is controlled at 1500 ~ 1630 ℃; inoculation treatment: add an inoculant at the bottom of the bag before the furnace is released, and pour molten iron into the bag, and the temperature is controlled at 1400-1460℃; casting: cast the inoculated molten iron into the sand mold, and the temperature is controlled at 1360-1410℃. The invention significantly improves the corrosion resistance of gray cast iron for water pumps.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and in particular relates to a corrosion-resistant gray cast iron for a water pump and a production method thereof. Background technique [0002] Cast iron is mainly an iron-carbon alloy material with a carbon content greater than 2.11%, which is widely used in machinery manufacturing. The chemical composition of ordinary gray cast iron in the prior art is usually carbon 2.8%-3.8%, silicon 1.3%-2.7%, manganese 0.5%-1.2%, phosphorus 0-0.3%, sulfur 0-0.15%, and balance of iron and impurities. The main elements in gray cast iron are carbon, silicon, iron, etc. Therefore, gray cast iron lacks passivation elements, and it is difficult to form a passivation film on the surface. Corrosion is very easy in water, especially in sewage. In addition, the pearlite structure is also To a certain extent, the corrosion resistance of gray cast iron is affected. Therefore, generally gray cast iron has p...

AI Technical Summary

Problems solved by technology

The main elements in gray cast iron are carbon, silicon, iron, etc., so there is a lack of passivation elements in gray cast iron, and it is difficult to form a passivation film on the surface. In water, especially in sewage, corrosion is very easy to occur. In addition, the pearlite structure is also Affects the corrosion resistance of gray cast iron to a certain extent

Therefore, the corrosion resistance of gray cast iron is generally poor, while gray cast iron for water pumps requires higher corrosion resistance.

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