Annealing of cold drawn steel
The annealing of cold drawn steel is commonly used in the production of preliminary heat treatment process. The majority of machine parts and engineering, mold rough can eliminate internal stress and composition of casting, forging and weldment inhomogeneity; can improve and adjust the steel mechanical properties, and organizational preparations for the next process to make after annealing. Performance of less demanding, less important parts and some ordinary castings, weldments, annealing can be used as the final heat treatment.
The annealing of the steel is heated to a suitable temperature, holding a certain period of time, and then slowly cooled in order to get close to the heat treatment process of a balanced organization. The purpose of annealing is uniform chemical composition, to improve the mechanical properties and process performance, eliminate or reduce stress and make the organization ready for the final heat treatment of parts. The annealing process is many types of steel, the heating temperature can be divided into two categories: one is in the annealing above the critical temperature (Ac3 or Ac1), also known as phase change recrystallization annealing. Including the fully annealed, fully annealed, isothermal annealing, the ball annealing and diffusion annealing; the other is in critical temperature (Ac1) following annealing, also known as low-temperature annealing. Including the recrystallization annealing, to stress and dehydrogenation annealing. The cooling method can be divided into continuous cooling annealing and isothermal annealing.
Quenching of cold drawn steel
Cold drawn steel quenching is very important in the heat treatment process, is widely used processes. Quenching can significantly improve the strength and hardness of the steel. If matched to a different temperature tempering can eliminate or mitigate the quenching stress, but also the strength, hardness and toughness with, to meet different requirements. Therefore, the quenching and tempering is inseparable from the two heat treatment process. Quenching the steel is heated to above the critical point is greater than the critical cooling rate (Vc) in the insulation after cooling, in order to get the heat treatment process of the martensite or lower bainite.
Post time: Sep-20-2019