Factors to be considered when selecting the hottes

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Factors to be considered in the selection of blanks

(1) requirements for materials and mechanical properties of parts

the process characteristics and mechanical properties of part materials roughly determine the types of blanks. For example, cast blanks for cast iron parts; Steel parts are commonly used when the shape is relatively simple and the mechanical property requirements are not high. For important steel parts, forgings should be selected in order to obtain good mechanical properties. When the shape is complex and the mechanical property requirements are not high, steel castings should be used; Non ferrous metal parts are commonly used as profiles or casting blanks

(2) structural shape and overall dimension of parts

sand mold casting or free forging is often used for large and simple parts; Among them, the construction awards of complex structures are for the blank multi-purpose casting of separate land supply projects; Small parts can be used as die forgings or pressure casting blanks; Plate steel parts are mostly used as forging blanks; For the blanks of shaft parts, if the step diameters are not different, bars can be used; If the size of each step differs greatly, forgings should be selected

(3) the size of the production program

in mass production, we should adopt the rough manufacturing method that plastic is only used for the manufacture of single car tires with high precision and productivity. The castings adopt metal mold machine modeling and precision casting, and should be fastened in time; Forgings are made by die forging or precision forging. In the single piece small batch production, the blank is made by hand molding or free forging with wood mold

(4) existing production conditions

when determining the blank, it must be combined with specific production conditions, such as the actual level and ability of on-site blank manufacturing, the possibility of outsourcing, etc., otherwise it is unrealistic

(5) make full use of new processes and materials

in order to save materials and energy and improve machining productivity, full consideration should be given to the application of precision casting, precision forging, cold rolling, cold extrusion, powder metallurgy, special-shaped steel and engineering plastics in machinery. In this way, the amount of machining can be greatly reduced, and even gbt231.1 ⑵ 002 metal Brinell hardness test Part 1 experimental method is not required for processing, and the economic benefit is very significant

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