What is the technological process of the rolling mill?

1. The continuous casting billet sent from the steel mill enters the heating furnace first.

2. After repeated rolling in the blooming mill, enter the finishing mill.

3. On the hot rolling production line, the rolled billet is softened by heating, sent to the rolling mill by the roller table, and finally rolled into the size required by users.

Steel rolling is a continuous operation, and the steel strip runs on the roller table with high speed, high degree of automation and high efficiency.

Ingots from open hearth furnace can also be turned into steel plates;

1, first of all, the teeth should be heated before being sent to the hot rolling line for rolling;

2. After dephosphorization to initial rolling, it enters the finishing mill through the roller table. The finishing mill consists of seven 4-high mills, with speed measuring rollers and flying shears in front, and the plate head is cut off.

3. The speed of finishing mill can reach 23m/s. ..

Hot rolled products are divided into steel coils and ingot plates, and the thickness of rails after hot rolling is generally several millimeters; If the user requires the steel plate to be thinner, it will be cold rolled.

Cold rolling process:

1. On the cold rolling mill, the uncoiler opens the steel coil, and then the steel strip is introduced into the five-stand continuous rolling mill to be rolled into a thin strip coil.

2. There are also five racks of ordinary steel coils with different specifications, which are processed according to various requirements of users.

Compared with hot rolling, the processing lines of cold rolling plants are scattered, and the cold rolling products mainly include ordinary cold rolled plates and coated plates, namely tinned plates, galvanized plates and color coated plates.

The steel coil sent from the hot rolling mill must be continuously treated for three times, and the oxide film must be removed with hydrochloric acid before it can be sent to the cold rolling mill. WISCO's tinplate production adopts tinning process.

There are two production processes of galvanized sheet: one is hot dip galvanizing, and the other is electro-galvanizing. They are used in power generation equipment, electromechanical equipment, light industry, food and household appliances.

With galvanized sheet as the base material, coated with various coatings on the reverse side, it becomes a color-coated steel plate.

In addition to plates, rolling mills also produce outstanding talents, such as section steel, rails, bars, round steel and wire rods. Its production technology and rolling principle are similar to those of medium and heavy plate, but the roll type used is completely different.

This is the general process. Different workshops will have different equipment and different technological processes.

Extended data

Main characteristics of safety production in rolling mill

Steel rolling is the production process of rolling steel ingots or continuous casting billets produced by steel mills into steel products.

According to its cross-sectional shape, it can be roughly divided into profiles, wires, strips, steel pipes and special steel products.

According to the different rolling temperatures, the methods of steel rolling can be divided into hot rolling and cold rolling; According to the relative motion relationship between the workpiece and the roll during rolling, it can be divided into longitudinal rolling and transverse rolling;

According to the forming characteristics of rolled products, they can be divided into ordinary rolling and special rolling.

Spinning rolling and bending forming are special rolling. Rolling, like other processing, is to make the metal plastically deform and form it at one time.

The difference is that steel rolling is carried out between rotating rollers. Rolling mills are divided into two categories, namely, main equipment or main train of rolling mills, auxiliary machines and auxiliary equipment.

Any equipment used to deform metal in a rotating roller is usually called main equipment.

The operation line of the main equipment arrangement is called the main train of the rolling mill. The main engine group consists of three parts: main motor, rolling mill and transmission machinery.

Rolling mills are divided into blooming mills and blooming mills, section steel mills (large, medium, small and wire rods), strip steel mills, steel tube mills and other special mills.

The cogging machine and section steel mill of the rolling mill are nominally based on the roll diameter, the strip mill is nominally based on the roll length, and the steel tube mill is nominally based on the maximum outer diameter of the steel tube that can be rolled.

2. Main safety technologies of steel rolling

(1) The rapid cooling technology for medium and heavy plate after rolling adopts the internationally advanced high-density pipe laminar cooling device. Through the controlled rolling and controlled cooling process in the production of medium and heavy plate, the production of special steel plate is improved and the mechanical properties of steel plate are improved.

(2) Controlled rolling and controlled cooling technology for bar production, which realizes the controlled temperature rolling of rolled pieces between the stand and the unit through specially designed coolers.

In order to improve the strength and toughness of bar, the slitting technology in bar production cuts a rolled piece into multiple rolled pieces through specially designed slitting guides or passes.

At present, the number of longitudinal tangents is the largest, and few steel mills realize mass production.

(3) Cold rolling, hot rolling and shape control technology, including:

Roll shape design and optimization: on-line detection, signal identification and flatness evaluation of strip steel; Shape control strategy and mathematical model with preset, feedforward and feedback.

(4) Hydraulic AGC technology, using high-performance hydraulic APC and AGC control system, with fast response and high control accuracy.

It is replacing electric AGC as the first choice technology for new rolling mills and rolling mills to be reformed.

(5) Complete sets of equipment and technology of double-stand reversible cold rolling mill, and different rolling passes are selected according to the material, specifications and production process conditions of rolled strip steel.

The rolling mill can flexibly adapt to the changes of strip material, specification and coil weight in a large range, and the product precision is high, so it can develop precision strip steel and non-ferrous metal foil strip.

(6) The complete set of equipment and technology for hot-rolled narrow strip steel production is close to wide strip steel in technology and equipment, and the loop oscillator and vertical coiler are replaced by laminar cooling and horizontal coiler;

With the addition of high-pressure water descaling before rough rolling, the surface quality and properties of strip steel are obviously improved, and the weight of coil is increased, reaching 1-2 tons.

(7) On-line surface quality inspection system based on image processing, using CCD camera to collect the surface images of products on the production line.

Through image processing and pattern recognition algorithm, the image is analyzed and processed in real time to detect whether there are defects on the product surface.

And get the size, location, type, grade and other information of defects, so as to achieve the purpose of online evaluation and control of product surface quality.

(8) Steel product development and performance optimization technology, including: the influence of process parameters on the formability of IF steel;

Study on ultra-fine grain high strength pure steel: Study on high strength microalloyed (Ti, Nb, V, B) steel.

(9) The analysis software package of the on-line measuring system for rod and wire size (ORBIS) developed by C++,

The system has the advantages of convenient and quick installation, stable and reliable operation, good man-machine interface, automatic generation and printing of reports, statistical analysis, historical record playback and query functions.

The application of (10) finite element simulation in metallurgical industry by general finite element software ANSYS,

; The secondary development method of finite element software DEFORM for bulk forming and heat treatment analysis and sheet metal forming analysis software DYNAFORM.

So that the development of new products and the improvement of existing processes are based on a more scientific and reliable basis.

References:

Baidu encyclopedia-steel rolling