In the production process of hot-rolled steel plate, the billet will be oxidized when heated in the heating furnace to form primary iron oxide scales, which adhere to the surface of the billet. In addition, in the rolling process, the billet will produce secondary oxidation, the formation of secondary iron oxide scale. The oxidation of high-pressure descaling valve rolling parts will not only cause the loss of metal due to oxidation, but also in the rolling process of rolling spokes, a part of the iron oxide scale is broken into small pieces and automatically falls off, and the other part is pressed into the metal surface to form inclusions and pits, resulting in surface quality defects of the steel plate. Therefore, the removal of iron oxide scale is a very critical process in the hot rolling production process, and this process of removing iron oxide scale is called descaling.

In order to effectively remove iron oxide scale, a variety of feasible descaling methods are used in production, mainly including manual descaling, simple mechanical descaling and high-pressure water descaling. The original manual descaling methods include iron wire, bamboo branches, apricot broom cleaning, salt sprinkling of hot-rolled parts, etc. These manual descaling methods have low working efficiency, high labor intensity, poor safety and poor descaling effect. Then a simple mechanical descaling is carried out with a toothed silver press, a wire brush and compressed air. Although the removal of the primary scale of the steel billet is increased, rather than manual phosphorus removal, the secondary scale produced during the rolling process is difficult to remove, and the surface defects of the steel plate have no essential changes.

The high-pressure descaling valve is not only conducive to the arrangement of the rolling process and the removal of the primary scale, but also conducive to the removal of the secondary scale in the rolling process, which can not only ensure the descaling effect, but also meet the requirements of continuously improving the surface quality of the steel plate. Therefore, the high-pressure descaling valve has been continuously recognized and accepted in the modern steel rolling production process, and has become an indispensable process equipment. At the same time, the development, application, improvement and promotion of high-pressure descaling valve technology have also become the development direction of steel rolling enterprises to improve the surface quality of steel plates.

High pressure descaling valve technology is developed from high pressure water jet technology, is the specific application of high pressure water jet technology.

Since the 1990 s, China has begun to design, develop and manufacture its own hot-rolled high-pressure descaling valve systems. Although these systems have their own advantages in form and different levels of system control, each hot-rolling enterprise has invested in construction and application according to its actual situation in China, which has comprehensively improved the surface quality of hot-rolled products in China and provided strong support for the development of high-quality products.

The working principle of high pressure descaling valve technology:

The high-pressure descaling valve refers to the impact force and erosion force generated by the kinetic energy of strong water flow during high-pressure water injection, as well as the shear force generated by the different cooling shrinkage of the substrate and the iron oxide scale layer, and the water infiltration between the substrate and the iron oxide scale The resulting steam expansion and bursting make the iron oxide scale break into small fragments and quickly separate from the surface of the substrate, while the high-pressure water scours the iron oxide scale in the set direction. In the process of high pressure descaling valve, four kinds of combined effects will be produced to achieve the purpose of descaling.

(1) Rupture effect: the use of high-pressure water injection.The extremely high kinetic energy generated by the vertical impact of the water flow destroys the iron sheet on the surface of the substrate, causing it to break and fall off.

(2) Cooling effect: When the high-temperature substrate is cooled under the action of high-pressure water jet, due to the different cooling shrinkage of the substrate and the iron sheet, a tangential shear force is generated, causing the iron sheet to fall off the substrate.