Heat treatment of metal is a process in which the metal workpiece is heated to a suitable temperature in a certain medium, and then cooled at different speeds after being kept BAI in this temperature for a certain period of time.Metal heat treatment is one of the important processes in mechanical manufacturing, compared with other processing techniques, heat treatment generally does not change the shape of the workpiece and the overall chemical composition, but by changing the internal microstructure of the workpiece, or change the chemical composition of the surface of the workpiece, to give or improve the performance of the workpiece.It is characterized by improving the intrinsic quality of the workpiece, which is generally not visible to the naked eye.In order to make the metal workpiece have the required mechanical properties, physical properties and chemical properties, in addition to reasonable selection of materials and various forming processes, heat treatment process is often essential.Iron and steel is the most widely used material in the machinery industry, the complex microstructure of steel can be controlled by heat treatment, so the heat treatment of steel is the main content of metal heat treatment.In addition, aluminum, copper, magnesium, titanium and their alloys can also be changed through heat treatment of their mechanical, physical and chemical properties, in order to obtain different performance.
Heat treatment includes annealing, tempering, hardening and tempering.
●Annealing: can reduce the hardness of metal materials, eliminate segregation, uniform composition, improve the structure defects in casting, rolling, forging and welding process;Refine grains, improve properties, and prepare good structures for final heat treatment;Reduce hardness, improve processing performance;Eliminate internal stress, stabilize size and reduce quenching deformation and crack.
●Normalizing: can improve the cutting performance of low carbon steel, can refine the grain, improve the comprehensive mechanical properties.
●Quenching: improve hardness, wear resistance, improve elasticity, improve strength and toughness;
●Tempering: to reduce and eliminate the internal stress of hardened steel.Stabilize the structure and size.
Post time: Feb-25-2021