A smooth and steady molding method of spherical graphite iron castings

Abstract

The invention discloses a smooth filling method of a nodular graphite casting, which comprises sand discharging and molding, and casting through a pouring channel. At casting, the invention adopts a slow speed casting, for a casting lower than 100 kilogram, the casting time is 15 to 30 seconds; for a casting of 100-1,000 kilogram, the casting time is 30 to 60 seconds; for a casting of 1,000 to 4,000 kilogram, the casting time is 60 to 180 seconds; for a casting more than 4,000 kilogram, the casting time is 180 to 480 seconds. The invention can realize smooth filling and guarantee good quality in nodular graphite castings.

Description

Technical field:

[0001] The invention relates to a mold filling method for ductile iron castings. Background technique:

[0002] With the development of the global economy and industrial technology requirements, more industrial equipment is developing towards large-scale, and the requirements for castings are increasing. Electricity has always occupied a basic position in my country's national economy. With the lack of coal, natural gas, oil and other mineral resources and the impending depletion, the development of traditional electric power using coal, natural gas, oil, water conservancy and nuclear materials as raw materials or resources Cause a lot of environmental burdens, such as environmental pollution, acid rain, climate anomalies, radioactive waste disposal, oil spills, etc. In this case, it is imperative for wind power to become an important follow-up energy source for the world, especially China. Wind energy resources are endless, and it is a renewable energy sour...

Examples

Embodiment 1

[0018] A method for stable filling of ductile iron castings, including sand molding, pouring through runners, and slow pouring speed during pouring. For castings less than 100 kg, the pouring time is 15 to 30 seconds (Examples 16, 23, 29 second). The runner is in the form of a ceramic tube, and a filter device for filtering impurities is installed in the runner. The filter device is a ceramic block with filter holes to filter out impurities. When placing sand for modeling, vibrate the sand mold to make the modeling firm.

Embodiment 2

[0020] When pouring, use slow pouring speed. For castings between 100 and 1000 kg, the pouring time is 30 to 60 seconds (for example, 30, 45, and 60 seconds); for castings between 1000 and 4000 kg, the pouring time is 60 to 60 seconds. 180 seconds; (examples 60, 120, 180 seconds); for castings larger than 4000 kg, the pouring time is 180 to 480 seconds (examples 180, 320, 480 seconds).

[0021] Specifically, such as:

[0022] 2 ton weight casting, pour time is 90 seconds. For a 10-ton casting, the pouring time is 300 to 480 seconds.

[0023] 100% of the castings produced by the invention pass visual inspection, magnetic particle inspection and ultrasonic inspection, and have no defects of sand inclusion and secondary oxide slag.

[0024] Due to the use of the present invention, the material properties of ductile iron castings are significantly improved. Taking the low temperature impact performance of wind turbine castings as an example, the -40±2°C low temperature impact pe...

Technical field:

[0001] The invention relates to a mold filling method for ductile iron castings. Background technique:

[0002] With the development of the global economy and industrial technology requirements, more industrial equipment is developing towards large-scale, and the requirements for castings are increasing. Electricity has always occupied a basic position in my country's national economy. With the lack of coal, natural gas, oil and other mineral resources and the impending depletion, the development of traditional electric power using coal, natural gas, oil, water conservancy and nuclear materials as raw materials or resources Cause a lot of environmental burdens, such as environmental pollution, acid rain, climate anomalies, radioactive waste disposal, oil spills, etc. In this case, it is imperative for wind power to become an important follow-up energy source for the world, especially China. Wind energy resources are endless, and it is a renewable energy sour...

Examples

Embodiment 1

[0018] A method for stable filling of ductile iron castings, including sand molding, pouring through runners, and slow pouring speed during pouring. For castings less than 100 kg, the pouring time is 15 to 30 seconds (Examples 16, 23, 29 second). The runner is in the form of a ceramic tube, and a filter device for filtering impurities is installed in the runner. The filter device is a ceramic block with filter holes to filter out impurities. When placing sand for modeling, vibrate the sand mold to make the modeling firm.

Embodiment 2

[0020] When pouring, use slow pouring speed. For castings between 100 and 1000 kg, the pouring time is 30 to 60 seconds (for example, 30, 45, and 60 seconds); for castings between 1000 and 4000 kg, the pouring time is 60 to 60 seconds. 180 seconds; (examples 60, 120, 180 seconds); for castings larger than 4000 kg, the pouring time is 180 to 480 seconds (examples 180, 320, 480 seconds).

[0021] Specifically, such as:

[0022] 2 ton weight casting, pour time is 90 seconds. For a 10-ton casting, the pouring time is 300 to 480 seconds.

[0023] 100% of the castings produced by the invention pass visual inspection, magnetic particle inspection and ultrasonic inspection, and have no defects of sand inclusion and secondary oxide slag.

[0024] Due to the use of the present invention, the material properties of ductile iron castings are significantly improved. Taking the low temperature impact performance of wind turbine castings as an example, the -40±2°C low temperature impact pe...

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