{"id":260,"date":"2024-08-03T21:15:00","date_gmt":"2024-08-03T13:15:00","guid":{"rendered":"http:\/\/www.1.com\/?p=238"},"modified":"2025-03-20T19:48:13","modified_gmt":"2025-03-20T11:48:13","slug":"about-detail-13","status":"publish","type":"post","link":"https:\/\/www.hexinmusu.com\/en\/about-detail-13.html","title":{"rendered":"Classification of metal manufacturing processes"},"content":{"rendered":"
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Hot working includes casting, forging and welding. Cold working, also known as metal cutting process, including tool cutting process (which has turning process, drilling and boring process, planing, inserting, broaching, milling process, abrasive cutting process; the processing of gear teeth). The following are briefly introduced. <\/p>\n\n\n\n

(i) Casting <\/h2>\n\n\n\n
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The process of casting involves pouring liquid metal into a casting mold and leaving it to cool to obtain a casting of a certain shape and character. This is the method of forming metal in the liquid state. Casting can produce billet blanks with complex shapes, especially complex internal cavities, with unlimited size and weight. Both single-piece production, can also be mass production, the use of most of the material from a wide range of sources, low prices, but also available scrap and waste parts, so the cost is low. Castings and parts of the shape and size close to the processing allowance is small. The disadvantage of castings is that there are many processes, process control is difficult. Due to the metal cooling internal stress, easy to defects, so the quality is not stable; due to its internal organization coarse uneven, its mechanical properties are not as high as forgings. There are also problems of high labor intensity and poor labor conditions. <\/p>\n\n\n\n

Casting production methods are divided into two categories of sand casting and special casting, sand casting-based.<\/p>\n\n\n\n

1,sand casting<\/strong> Most sand molds are still made by hand. Sand casting is mainly used for cast iron, cast steel, cast copper, cast aluminum and other materials casting production. Castings structural design, to consider the casting process and metal making performance requirements, to prevent the production of shrinkage holes, shrinkage loosening, underpouring, cold segregation, deformation and cracks and other defects, should pay attention to the following issues: \u2460 castings should have a reasonable wall thickness and structural slope, casting wall thickness as uniform as possible. \u2461 casting wall connection: casting wall connection should have structural rounded corners. Avoid cross and sharp angle connection, thick wall and thin wall articulation should be a gradual transition. \u2462 Castings should avoid excessive horizontal plane. \u2463 In order to prevent the casting from warping and deformation, for the larger flat castings and the long box with uneven wall thickness, it should be designed into a symmetrical shape or increase the ribbed plate to improve its stiffness. \u2464 Avoid the casting shrinkage is hindered such as common wheel-shaped castings, the spokes of the wheel is an even number of linear shape. However, for alloys with large shrinkage, cracks are sometimes produced due to excessive stress. In order to prevent cracks, can be made of curved spokes, in order to take the spokes or rim of the wheel deformation, reduce the internal stress. (6) according to the principle of sequential solidification design casting structure The cast steel shell shown in the figure, will be changed to the right side of the appearance of the shell at the bottom of the 76mm to maintain a uniform wall thickness, and gradually increase the wall thickness until the flange with the flange, to ensure that the shell in accordance with the sequential solidification, no longer produce shrinkage defects. <\/p>\n\n\n\n

2,Specialty Casting<\/strong> <\/p>\n\n\n\n