Introduction of steel rolling process

The billets from the steel mill are only semi-finished products, and they must be rolled in the rolling mill before they can become qualified products.

The continuous casting billet sent from the steel mill first enters the heating furnace, and then enters the finishing mill after repeated rolling in the blooming mill. Rolling steel belongs to metal pressure processing. To put it simply, rolling steel plate is like pressing noodles. After multiple squeezing and pushing with a rolling pin, the noodles become thinner and thinner. In the hot rolling production line, the billet is heated and softened, sent to the rolling mill by the roller table, and precisely rolled into the size required by the user. Steel rolling is a continuous and uninterrupted operation. The steel strip runs fast on the roller table, and the equipment has a high degree of automation and high efficiency. The steel ingots from the open hearth furnace can also be used as steel plates, but they must first be heated and bloomed before they can be sent to the hot rolling line for rolling. ~ 250mm, after dephosphorization to rough rolling, it enters the finishing rolling mill through the roller table. The finishing rolling mill consists of seven 4-high rolling mills. The front of the machine is equipped with speed measuring rolls and flying shears, and the head of the plate is cut off. The speed of the finishing mill can reach 23m/s. The hot-rolled products are divided into two types: steel coils and ingot-type plates. The thickness of the hot-rolled steel rail is generally several millimeters. If the user requires a thinner steel plate, it needs to be cold-rolled.

Compared with hot rolling, the processing lines of cold rolling plants are relatively scattered. Cold rolling products mainly include ordinary cold-rolled sheets, coated sheets, that is, tin-plated sheets, galvanized sheets and color-coated sheets. The steel coils sent from the hot rolling mill must first undergo three consecutive technical treatments. First, the oxide film is removed with hydrochloric acid, and then it can be sent to the cold rolling mill. On the cold rolling mill, the coil is opened by the decoiler, and then the strip is introduced into the five-stand continuous rolling mill to be rolled into thin coils. There are also ordinary steel coils of different specifications from the five racks, which are processed according to the various requirements of users.

The cold-rolling factory produces a variety of products of different quality. The ones that fly straight down like the Milky Way fall for nine days are tin-plated sheets, the ones that shine silver are galvanized sheets, and those that are red, yellow, and blue are colorful ones. Coated steel. Tinplate is the raw material for the manufacture of cans and cans, also known as tinplate. In the past, all the tinplates needed in my country were imported. Since the mass production of tinplates by WISCO, some of them have replaced imported goods. WISCO adopts the electroplating process for the production of tinplates. These tinplates are like mirrors, and the light reflects people, just as the poet described: "The steel rolling workers skillfully hand-painted brocade tents, and thousands of silver mirrors are given to the beloved girl. Did you know that on that Wife's washing machine, there is the fragrance of our sweat."

There are two production processes for galvanized sheet, one is hot-dip galvanizing and the other is electro-galvanizing. What's special about that unpretentious package is the silicon steel sheet, which is used in power generation equipment, electromechanical equipment, light industry, food and home appliances. The galvanized sheet is used as the base material, and various coatings are applied on the reverse side to become the color-coated steel sheet. Due to the advanced technology, the coating is very firm and can be directly used in home appliances and decorative materials. In addition to flat products, rolling mills also produce long products such as sections, rails, bars, round bars and wire rods. The production process and rolling principles are similar to those for flat products, but the roll profiles used are completely different.