The purpose of heat treatment of large forgings after forging is to refine the coarse grains caused by the forging process, eliminate work hardening and residual stress, reduce hardness, improve machining performance, prevent white spots in the forging, ensure the required metal structure and mechanical properties, and prepare for the final heat treatment. Commonly used are the following.
Complete annealing, eliminate the coarse and uneven structure and Weil structure caused by the forging process, refine the grain, and eliminate the residual stress of the forging and reduce the hardness.
pheroidizing annealing to obtain spheroidal cementite and ferrite structure, which not only has low hardness, but also is easy to get a smooth machining surface during cutting, and is not easy to produce deformation cracks during subsequent quenching.
Isothermal annealing can not only shorten the annealing time, but also obtain uniform structure and reduce hardness. In important large forgings, it can also be used to diffuse hydrogen to prevent the production of white spots. Annealing process is generally adopted for post-forging heat treatment of aluminum alloy and copper alloy. The purpose is to eliminate work hardening, stress and improve plasticity.
Normalizing, can get finer pearlite, can improve the mechanical properties of forgings suitable for machining.
Normalizing and high temperature tempering - eliminate the stress generated during normalizing cooling, improve plasticity and toughness.
Tempering, forging has good comprehensive mechanical properties.
Henan Forging Emperor Industry Co., Ltd. is an enterprise with more than 20 years of experience in seiko forging. Over the years focus on forging all kinds of metal products, in the field of forging processing, always uphold the principle of professional and fine, to provide customers with high quality products.