CN104785744A - A High Pressure Flange Centrifugal Casting Process - Google Patents

Abstract

The present invention provides a high-pressure flange centrifugal casting process, the steps of which include smelting process, centrifugal pouring, cooling, rough processing process, and heat treatment process. Centrifugal pouring improves the cooling rate of the casting and the utilization rate of the metal. Under the condition of strengthening the refining and degassing of the alloy liquid and improving the purity of the alloy liquid, centrifugal casting can strengthen the cooling of the alloy liquid. At the same time, under the action of the centrifugal force field, the oxide inclusions in the alloy liquid float on the inner surface of the casting, realizing the directional solidification of the casting.

Description

A High Pressure Flange Centrifugal Casting Process

technical field

The invention relates to the field of flange manufacturing, in particular to a high-pressure flange centrifugal casting process.

Background technique

Since the birth of high-pressure flanges in the 1950s, they have been widely used in petroleum and petrochemical, oil and gas exploitation, industrial gas production, petroleum refining, food processing, chemical industry, environmental engineering, mineral and nuclear power, aerospace, shipbuilding, synthetic fuel processing, Oxidation and liquefaction of coal and other fields. In the Chinese market, such products are completely dependent on imports, and there is no domestic company that can design and produce them. It was not until 2005 that this situation was broken by domestic Chengdu Zhiyuan Machinery Technology. High-pressure flanges are mainly used in the installation of pipelines. High-pressure flange connections are an important connection method in pipeline construction. They mainly connect pipes and pipes, which play an important role and value. The high-pressure flange connection is to fix two pipes, pipe fittings or equipment on a flange plate first, add flange pads between the two flange plates, and fasten them together with bolts to complete the connection.

Contents of the invention

The present invention provides a high-pressure flange centrifugal casting process. In order to achieve the purpose of the present invention, the technical scheme of the present invention is as follows:

A high-pressure flange centrifugal casting process is characterized in that the specific steps are:

(1) Smelting process: Put copper and returned materials into the induction furnace at the same time, and melt them quickly. When the copper temperature reaches 850-900°C, add the preheated Al-Fe master alloy. When adding, the master alloy should be pressed into the copper liquid In the furnace, stirring and fluxing are carried out, then Al is added, zinc dichloride is pressed into the bell jar for dehydration, degassing and refining, stirring carefully, after the furnace inspection is qualified, the scum is removed, and the furnace is poured;

(2) Centrifugal casting: during centrifugal casting, the inner surface of the mold is sprayed with zinc oxide paint, the pouring temperature is controlled at 800-900°C, the method is first fast and then slow, the pouring speed is 5-8kg/s, and the centrifugal speed is 630- 680r/min;

(3) Cooling: Cool until the surface of the casting is dark red, that is, 600-700 °C to stop the machine and demould;

(4) Rough machining process: rough machining of castings. During rough machining, the thin walls on both sides of the flange should be left 3-5mm on one side in the diameter direction, and 3-5mm on one side in the length direction;

(5) Heat treatment process.

Preferably, the coating ratio in step (2) is 12% zinc oxide, 2% water glass, and the balance is water.

Preferably, in the heat treatment process of step (5), the quenching temperature is controlled at 730-770°C, and the tempering temperature is controlled at 590-630°C.

Beneficial effects: the present invention provides a high-pressure flange centrifugal casting process, the steps of which include smelting process, centrifugal casting, cooling, rough machining process, and heat treatment process. Centrifugal casting improves the cooling speed of castings and the utilization rate of metal. In the case of strengthening the refining and degassing of alloy liquid and improving the purity of alloy liquid, centrifugal casting can strengthen the cooling of alloy liquid, and at the same time, under the action of centrifugal force field, the alloy The oxidized slag in the liquid floats on the inner surface of the casting to realize the directional solidification of the casting.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

A high-pressure flange centrifugal casting process is characterized in that the specific steps are:

(1) Smelting process: Put copper and returned materials into the induction furnace at the same time, and melt them quickly. When the copper temperature reaches 850°C, add the preheated Al-Fe master alloy. When adding, the master alloy should be pressed into the copper liquid. Stirring and fluxing, then adding Al, pressing zinc dichloride into the bell jar for dehydration, degassing and refining, stirring carefully, after passing the inspection before the furnace, removing scum, and pouring out of the furnace;

(2) Centrifugal casting: during centrifugal casting, the inner surface of the mold is sprayed with zinc oxide paint, the pouring temperature is controlled at 800°C, and the pouring speed is 5kg/s, the centrifugal speed is 630r/min, and the pouring temperature is controlled at 800°C. The ratio is 12% zinc oxide, 2% water glass, and the balance is water;

(3) Cooling: Cool until the surface of the casting is dark red, that is, 600°C to stop the machine and demould;

(4) Rough machining process: rough machining of castings. During rough machining, the thin walls on both sides of the flange shall be 3mm on one side in the diameter direction and 3mm on one side in the length direction;

(5) Heat treatment process: the quenching temperature is controlled at 730°C, and the tempering temperature is at 590°C.

The invention provides a high-pressure flange centrifugal casting process, the steps of which include smelting process, centrifugal pouring, cooling, rough machining process and heat treatment process. Centrifugal casting improves the cooling speed of castings and the utilization rate of metal. In the case of strengthening the refining and degassing of alloy liquid and improving the purity of alloy liquid, centrifugal casting can strengthen the cooling of alloy liquid, and at the same time, under the action of centrifugal force field, the alloy The oxidized slag in the liquid floats on the inner surface of the casting to realize the directional solidification of the casting.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by the description of the present invention, or directly or indirectly used in other related technical fields, shall be the same as The theory is included in the patent protection scope of the present invention.

Claims (3)

1. A high-pressure flange centrifugal casting process is characterized in that its concrete steps are: (1) Smelting process: Put copper and returned materials into the induction furnace at the same time, and melt them quickly. When the copper temperature reaches 850-900°C, add the preheated Al-Fe master alloy. When adding, the master alloy should be pressed into the copper liquid In the furnace, stirring and fluxing are carried out, then Al is added, zinc dichloride is pressed into the bell jar for dehydration, degassing and refining, stirring carefully, after the furnace inspection is qualified, the scum is removed, and the furnace is poured; (2) Centrifugal casting: during centrifugal casting, the inner surface of the mold is sprayed with zinc oxide paint, the pouring temperature is controlled at 800-900°C, the method is first fast and then slow, the pouring speed is 5-8kg/s, and the centrifugal speed is 630- 680r/min; (3) Cooling: Cool until the surface of the casting is dark red, that is, 600-700 °C to stop the machine and demould; (4) Rough machining process: rough machining of castings. During rough machining, the thin walls on both sides of the flange should be left 3-5mm on one side in the diameter direction, and 3-5mm on one side in the length direction; (5) Heat treatment process. 2. A high-pressure flange centrifugal casting process according to claim 1, characterized in that the coating ratio in step (2) is 12% zinc oxide, 2% water glass, and the balance is water. 3. A high-pressure flange centrifugal casting process according to claim 1, characterized in that, in step (5) heat treatment process, the quenching temperature is controlled at 730-770°C, and the tempering temperature is controlled at 590-630°C.