Flange with neck and its preparing method

Abstract

The present invention relates to a LF 2R High-neck flange, obtained by extrusion casting, has no weld seam, and its microstructure presents a continuous streamlined structural feature, and its streamlined shape is consistent with the direction of the flange shape; a preparation method of a LF2R high-neck flange of the present invention , the metal liquid crystallizes and solidifies under the pressure in the mold casting cavity composed of the upper pressure head, the female mold (5), the mold core (4) and the ejector pin (9); the extrusion casting process is: pouring at 700±15°C , The mold temperature is 250±50°C. When the mold is closed, the pressure gradually rises for no more than 5 seconds. When it reaches 25MPa, the pressure is kept for 1 minute 30 seconds to 2 minutes. The necked flange casting of the present invention has few internal defects, compact structure and high mechanical properties. The squeeze casting process has strong applicability, wide range of material selection, simple process, good stability, high casting quality, and easy casting. Implement automation.

Description

Technical field: [0001] The invention relates to a pipe connector flange, and in particular provides a necked flange obtained by a squeeze casting method and a preparation method thereof. Background technique: [0002] Flange is an indispensable part in pipeline connection, with a wide range of applications and a large market demand. Among them, the neck flange is a relatively complicated variety of flanges. At present, domestic enterprises specializing in the production of flanges mainly use the following three methods for production. The first method is the method of plate processing, that is, the rolled plate is blanked and machined into a flange; at the same time, the plate is machined and machined, the coiled plate is welded into a cylindrical shape, and the flange neck is formed after shaping; The blue plate and the flange neck are welded together, and the finished product is machined as a whole; the disadvantage of this method is that the material utilization rate is...

AI Technical Summary

Problems solved by technology

The first method is the method of plate processing, that is, the rolled plate is blanked and machined into a flange; at the same time, the plate is machined and machined, the coiled plate is welded into a cylindrical shape, and the flange neck is formed after shaping; The blue plate and the flange neck are welded together, and the finished product is machined as a whole; the disadvantage of this method is that the material utilization rate is low, the process is many, the process is complicated, and the cycle is long. In addition, the product has two welds, and the airtightness is not good enough. Guaranteed, poor reliability

The second method is the forging method, that is, the process route of casting, ring rolling and turning machine to add the flange neck. This method has no weld seam, the air tightness can be reliably guaranteed, and the mechanical properties of the product are good. The quality is stable and reliable, but this method requires a large investment in equipment, and only those factories with strong equipment and technical capabilities can adopt it. It is only suitable for the production of standard flanges with large market demand, and the material utilization rate is only 50%.

The third method is the casting method, that is, the neck flange is directly manufactured by casting method. Although the manufacturing cost of this method is low, the quality cannot be guaranteed, and the material required for some flanges is forged alloy. Suitable for casting, this method is powerless, so the flange cast by this method is mainly used in occasions with low pipeline pressure and low reliability requirements, such as gray cast iron and ductile iron flanges, etc., which are widely used in water supply and drainage projects

Images