Linear guide rail annealing annealing, quenching, tempering principle

Time:2018/6/4Author:adminClick: 1760
Linear guide rail annealing annealing, quenching, tempering principle
(one). Type of annealing
1. Complete annealing and isothermal annealing
Completely Annealed and Weigh-In-Crystal Annealing, commonly referred to as Annealing, is used primarily for casting, forgings, and hot-rolled sections of various carbon steels and alloyed steels of sub-eutectoid compositions, and is sometimes used for welded structures. It is generally used for the ultimate heat treatment of some unimportant workpieces or as a pre-heat treatment for some workpieces.
2. Spheroidizing annealing
Spheroidizing annealing is mainly used for hypereutectoid carbon steels and alloy tool steels (such as, for example, cutting tools, measuring tools, and steels used in molds). Its main purpose is to reduce the hardness, improve the machinability, and prepare for the subsequent quenching.
3. Stress relief annealing
Stress-relief annealing, also known as low-temperature annealing (or high-temperature tempering), is used to eliminate residual stresses in castings, forgings, weldments, hot-rolled and cold-drawn parts. If these stresses are not eliminated, steel pieces will be deformed or cracked during the subsequent cutting process after a certain period of time.

(two). Quenching
In order to improve the hardness of linear guides, the main form is through heating, insulation, and quick cooling. The most common cooling media are brine, water and oil. Salt water quenched workpieces, easy to get higher hardness and smooth surface, not easy to produce hardened hard spots, the disadvantage is that it easily lead to serious deformation of the workpiece, or even cracking. The use of oil as quenching medium is only suitable for supercooling, and the stability of austenite is better than that of some alloy steels or small-size carbon steel workpieces.
(three). Tempering
1. Reduce brittleness, eliminate or reduce internal stress, steel quenching there is a lot of internal stress and brittleness, if not tempered, steel will often cause deformation or even cracking state.
2. The mechanical properties required for the workpiece are obtained. After quenching, the workpiece has high hardness and high brittleness. In order to meet various performance requirements of various workpieces, the hardness of the workpiece is adjusted by appropriate tempering, the brittleness is reduced, and the required toughness and plasticity are obtained. .
3. Stable workpiece size
4. For some alloy steels that are difficult to soften after annealing, high-temperature tempering is generally used after quenching (or normalizing) to concentrate carbides in the steel and reduce hardness, which facilitates cutting.