Machining heat treatment method

01 Annealing


The definition of annealing treatment: a metal heat treatment process in which metal parts are heated to a certain high temperature, kept for a period of time and then allowed to cool naturally


Its main function: reduce the hardness of parts and improve cutting performance


Eliminate residual stress of parts, stabilize size, reduce deformation and crack probability


Refining crystal grains, adjusting structure, eliminating material structure defects


Uniform material organization and composition, improve material performance or prepare organization for subsequent heat treatment process


02 Normalizing


The definition of normalizing treatment: heat the metal parts to a certain high temperature, keep them for a period of time, and then let them cool in the air by spraying water, spraying, blowing, etc. Different from annealing treatment, the cooling rate is Faster, so the material structure obtained should be finer and the mechanical properties have also been improved


Its main function:


A. Remove the internal stress of the material;


B. Reduce the hardness of the material and increase the plasticity


03 Quenching treatment


The definition of quenching treatment: heat the metal parts to a temperature above the critical temperature Ac3 or Ac1, keep it for a period of time to make it fully or partly austenitized, and then quickly cool it to below Ms at a cooling rate greater than the critical cooling rate Heat treatment process for martensite transformation


Its main function:


A. Significantly improve the rigidity, hardness, wear resistance and fatigue strength of parts;


B. Meet the physical and chemical properties of some special steels such as ferromagnetism and corrosion resistance.


04 Tempering treatment


The definition of tempering treatment: refers to the steel after quench hardening or normalization treatment and then immersed in a period of time below the critical temperature, and then cooled down at a certain speed to increase the toughness of the material Heat treatment method


Its main function:


A. Eliminate the residual stress generated during quenching of the workpiece to prevent deformation and cracking


B. Adjust the hardness, strength, plasticity and toughness of the workpiece to achieve better performance requirements


C. Stable organization and size, ensure accuracy;


D. Improve and improve processing performance.