Heat treatment of steel - an important process of the production of an alloy of iron, which helps to improve its useful properties.Today, this procedure is used to convert the natural characteristics of most metal products.
Heat treatment of steels implies consistent implementation of three phases:
- heating iron alloy to the desired temperature.
- Exposure become over time.
- cooling.
What happens to the iron alloy with such a procedure?
Heat treatment consists of the following steps:
1. Annealing.This process is mainly used for low tide, rolling and forging.This procedure is necessary to reduce the hardness or reduce internal stresses that are created in the welded products.In addition, annealing is used for the preparation of the metal structure to a subsequent thermal treatment in order to improve the character of its heterogeneity.This method of heat treatment of steel included 45, 45H, 40XC, 40XH other marks and iron alloy.
2. Normalization.This procedure differs from the previous process, the nature of passing the cooling step.The last step is carried out after holding parts.Particular attention is paid to a given temperature.In this case, the steel is obtained with a small, but higher hardness.The structure of these fine-grained products.Thus, normalization of steel necessary to correct the composition of the weld, as well as to obtain the desired configuration.
3. Hardening.This step is related to the processing of steel, is used for forgings, castings, forgings, as well as parts of processed mechanically in order to increase strength, hardness, corrosion resistance, wear resistance and other important characteristics.This process involves heating the iron alloy to a temperature above or in the range of its transformation.Extract with such termopokazatele steel and the subsequent cooling is carried out usually at a slightly higher speed.For this purpose most often are aqueous salt solutions NaOH, oil and air.Thus, for example, heat treatment of steel 40X at this stage is carried out in oil.Quite a rare large size parts are subjected to tempering in water immediately following the release of the low.Often the products of this brand are the iron alloy phase by heating the high-frequency currents.The result is a high solid surface.
4. Vacation.This procedure consists in heating the quenched steel to a certain temperature.Further metal is exposure, as well as cooling.The last step is generally carried out in air.
5. Aging.This step consists in maintaining an iron alloy with a metastable structure for a long time.Wherein the temperature should not be below room temperature.This procedure allows the metal structure partially move to a more stable state by changing their mechanical and physical properties.
6. Cold treatment.This step is a continuation quench cooling, which was suspended at room temperature.The indicator for the metal is not critical.
Applications iron alloy
Since steel heat treatment procedure can significantly improve the performance of parts made of iron alloy of different brands, it is in great demand in all areas of industry.Is not an exception mechanical engineering, aircraft construction, tank-building, production of concrete products.Products which have undergone heat treatment may be used under increased dynamic load and vibration.In addition, these alloys are used in the construction of iron skyscrapers, factories and bridges.
