Bearing steel annealing, quenching, tempering consumption principle

( A) 。 The variety of annealing 1. Full annealing and full annealing and isothermal annealing weighing annealing crystallization, ordinary annealing for short, is mainly used for the annealing of hypoeutectoid composition of carbon steel and alloy steel casting, forging and hot rolled profiles, sometimes used for welding structure. Common used as a final heat treatment, some not important artifacts or as a certain workpiece heat treatment in advance. 2. Spheroidizing annealing fireball annealing is mainly used for the eutectoid carbon steel and alloy tool steel ( Such as manufacturing cutters, measuring tool and die steel used in the) 。 The main purpose is to reduce the hardness and improve cutting workability, and to prepare for after quenching. 3. The stress relieving the stress relieving (also called low temperature annealing Or high temperature tempering) , the annealing is mainly used to eliminate the casting, forging, welding parts, rolling, the residual stress of cold-drawn pieces, etc. If these stress will not be offset, will make up the steel after a certain period of time, or during subsequent machining deformation or cracks. ( 2) 。 Quenching hardness in order to progress the way, is the main way through heating, heat preservation, rapid cooling. Is the most commonly used cooling medium brine, oil and water. Brine quenching workpiece, easy to get high hardness and bright appearance, it is not easy to produce soft point of quenching is not hard, but it is easy to make the workpiece deformation, cracking and attack. Oil as quenching medium is only applicable to the stability of the supercooled austenite match some of the alloy steel or small size of the carbon steel workpiece quenching. ( 3) 。 Tempering 1. Reduce the brittleness, eliminate or reduce internal stress, there is a big internal stress after the steel quenching and brittleness, if not timely often makes the steel deformation and cracking. 2. Obtain workpiece, on the mechanical properties of the requested work piece after quenching, high hardness and brittleness is big, in order to meet the request of the different performance of various artifacts, cooperate to adjust the hardness can be properly tempering, decrease the brittleness, get the demand of toughness and plasticity. 3. Stable workpiece size 4. About some annealing softening hard alloy steel, quenching ( Or normalizing) Often used after high temperature tempering, the carbides in the steel appropriate collection, the hardness is reduced, and machining.