Steel austenitic state from the cooling process is the key process of heat treatment, because ultimately depend on the performance of the steel cooling transformation of austenite after, so what kind of cool way to get what the organization is crucial. Workpiece cooling rate is usually based on the destination, and may need to decide, online often steel pipe cooling air-cooled and air-cooled mainly by way of cooling. Online normalization cooling control has two aspects, one is the middle of a small cooling bed, two large cooling bed sheets sizing or less after the cooling performance of these two aspects have a direct impact on the final product.
After the end of the rolling mill due to a large amount of rolling deformation and rolling in the recrystallization region, which makes rolling blank pipe after the fine grains can be obtained, if this rapid cooling to take measures to capillary rI less rapidly cooled to pills, can prevent austenite grain growth, maintaining a fine grain size state as to create conditions for normalizing. For moderate shortage of pipe wall thickness for rapid cooling after rolling is more important, generally improving the cooling rate is often used air-cooled (mist cooling can also be considered). Online normalization completion of certain steel reheating furnace cooling and heating was continued after entering in the middle of a small cooling bed. One thing to note, that we must control the shortage tube into the blast furnace temperature to avoid the phase transition has not been completed in the previous furnace, or likely to cause the phenomenon of mixed crystals. After cooling sizing or large cooling bed sheets obtained after reduction after the final organization, which is to get the ultimate performance. Therefore, a large cooling bed gasification process cooling is online often a key step. The cooling temperature and the cooling rate is directly related to the selection of the final properties of the case. It should be noted that, in the final cooling process cooling method must be carefully chosen, as if cooling properly, may cause differences in the elbow or greater performance with a steel pipe and so on.
Conducted on hot-rolled steel metal structure designed to control and improve the mechanical properties of the steel pipe cooling process. The traditional steel thermal processing (rolling) temperature control systems and cooling systems within a specific range of pipe process. Heat treatment or heat after rolling controlled cooling after quenching, also known as reinforced steel rolling, finishing after the use of steel in the surface hardening of austenitic state directly, with their sleeves outgoing waste heat tempered to improve ductility, improve the toughness of the steel Xun good overall performance. This process is simple, save energy, improve the operating environment: the trial bar appearance, flat strip, receive greater economic benefits, at home and abroad to get a wide application in the arts. Overall performance of steel, such as yield strength, anti-bending, welding performance, fatigue, impact toughness, etc., depending on the chemical composition of the steel, deformation conditions, finish rolling temperature, muscle diameter, cooling conditions, the cooling rate and self-tempering temperature factor. Entire steel weave with performance stability and homogeneity of the production control process parameters, bar length, type of cooling equipment, water quality, water temperature and its control is closely related to the rational choice is to get the process rolling control is required for the performance of reinforced key. By controlling the cooling process, and strengthen steel, instead of re-heating for quenching of quenched and tempered steel. Strengthening the use of controlled cooling heat strengthened steel reinforcement and general comparison not only because of the use of the rolling heat, do not need to re-heat, saving fuel and heat, shorten the production cycle, improve productivity, reduce the cost of production of high-strength steel but also has a higher mechanical properties.
