Metal forming

Metal forming - processmanufacturing of blanks and shaped details by plastic deformation of the starting material. This kind of processing can be subjected to materials that have sufficient plastic properties. For brittle alloys, such as cast iron, this method of shaping is not applied because of the high probability of destruction of the part as a result of a strong external influence.

Technology of production of semi-finished and finished productsproducts in this way involves the use of material that is in both cold and hot state. This entails significant differences in the properties of the finished product. Processing of metals by pressure will only slightly change the structure, hence, the physical and mechanical properties of the material, if it was originally in a hot state.

Molding of the billet from metal in coldcondition is used in the case of manufacturing a large batch of small high-quality parts. This is due to the fact that in this state the material hardens, accompanied by a change in its properties. In particular, the strength characteristics of the finished product are increased.

The theory of metal forming is based onon the application of the plastic properties of these materials. In particular, their ability to permanent deformation, in which the body retains its dimensions and shape, is used, even after the external load has been removed. The change in the geometric parameters of the product is due to a static or dynamic external pressure, which causes considerable stresses in the alloy, the value of which exceeds the yield point considerably.

The following types of metal forming are distinguished:

• rolling, during which the material to be processed is subjected to compression on special equipment by passing between the rollers, which are informed of the rotational motion;

• drawing. In this case, only long products, such as wire, bar or pipe, are formed. The essence of this treatment is the pulling of the parent metal through a hole of smaller size than the diameter of the initial workpiece, located in a special tool - a dredge;

• free forging, which provides fora consistent change in the shape and size of the part in the hot state as a result of successive impact by the hammer or pressure created by the press. This kind of processing allows to improve the structure and properties of forging;

• Stamping, which can be both sheet and three-dimensional. In both cases, the same type of equipment is used: a press and a stamp, but the ratio of the dimensions of the workpiece is different;

• pressing, in which the material is extruded from a closed mold having holes.

Processing of metals by pressure has a number of advantages, among which one can distinguish:

• the possibility of mechanization and automation of the process of manufacturing parts;

• increase in the utilization factor of the material;

• the manufacture of products of various shapes and sizes, with no further machining required for individual parts, for others - its volumes are significantly reduced;

• increase the productivity of the process of production of various products;

• improvement of mechanical properties of alloys.

The treatment of metals by pressure is quite wideis used in the industrial complex of our country. This method produces various body parts that have complex geometry and large dimensions. If necessary, if the required dimensions, shape or surface quality are not achieved with this shaping method, the next step is machining. If it is necessary to increase the operational properties of the finished product, then the final stage is heat treatment.