What Are Lubrication Methods Of Steel Rolling Mills?

The lubrication methods of Steel Rolling Mills are as followings: 

The basic methods of steel rolling mills lubrication are thin oil lubrication, dry oil lubrication, and oil mist lubrication. Thin-oil lubrication uses mineral oil (liquid lubricant) as a lubricant. Because the thin oil has the characteristics of fluidity, adhesion to the metal surface, certain viscosity and heat capacity, it can adhere to the surface of the lubricated part and can form fluid dynamic pressure, so that the friction surfaces are separated from each other. It also removes the heat generated by the friction from the friction surface. The performance of thin oil is relatively stable and has a certain antiseptic effect. However, the thin oil is not easy to seal, and the lubricating surface of the device easily invades impurities such as water and iron oxide.

Oil mist lubrication is a new way of lubrication. In the atomizer, the lubricating oil is atomized into extremely small oil particles under the action of filtered and compressed air. The fine oil particles are then mixed with the compressed air, and a small oil droplet is condensed onto the friction surface through the pipe and the condensation nozzle. Oil mist lubrication consumes less fuel, has a lower operating temperature, has a better lubrication effect, and saves maintenance costs. However, oil mist lubrication has high requirements for sealing of steel rolling mills, and strict requirements for oil quality and compressed air.        

Dry oil lubrication actually uses a grease-like grease (also called butter) as a lubricant. Grease is a grease made of lubricating oil plus thickener. Besides its lubricating property, it has strong adhesion, so it has good protection performance and seals the friction surface to avoid metal corrosion and impurity intrusion. After adding the grease once, the steel rolling mills can be operated for a period of time and is convenient to use. However, the energy consumption during operation is larger than that of thin oil, and it is not suitable for high-speed operation equipment.

What Are The Advantages Of The New Design Rolling Mill Equipment?

What Are The Advantages Of The New Design Rolling Mill Equipment?

What are the advantages of the new design rolling mill? What are the special rolls equipped?

As we know that in the process of improving the rolling mill equipment, its structure design has been obviously optimized and upgraded. So do you know what new advantages this rolling mill has after new design improvements? In fact, one of the most attractive aspects of the new equipment is the flexible adjustment of rolling speed.

In this way, in actual production, the working performance of rolling mill equipment will be brought into full play, which is also the basis of realizing automation and continuous operation. Of course, it also has many other advantages, such as when the latest design and production equipment in the production process can also ensure the tensile strength of finished steel bars, but also can greatly improve the elongation of broken steel bars and the maximum total elongation, and further improve the mechanical properties of products, to overcome the problem of low ductility of cold-rolled steel bars.

In addition, after improvement, the current rolling mill equipment adopts the passive one-rolling and one-towing production mode, which can realize two-pass rolling. It not only solves the problem of speed matching but also changes the traditional four-pass rolling mode and improves production efficiency significantly. At the same time, the automatic control calculation is flexibly applied to ensure that the product appearance size is accurate and the surface quality is excellent.

From the above introduction, we can see that continuous innovation and improvement will be able to further improve the performance of rolling mill equipment on the basis of the past. At the same time, it also significantly improves the quality of finished steel products, while improving production efficiency, bringing maximum benefits to customers. So, do you know what special rollers are equipped with them? In fact, rolls are very important components for any rolling mill equipment.

Even some rolling mills are equipped with special rolls to meet these special rolling requirements. For example, cemented carbide rolls, which are pressed and sintered with tungsten carbide powder, are suitable for high-speed rolling because of their excellent wear resistance. This roll is usually used in high-speed wire rod mills.

What Are The Common Shearing Machine Of Rolling Mill?

What Are The Common Shearing Machine Of Rolling Mill?

There are many kinds of shearing machines used in rolling mill workshop. According to the shape and configuration of shearing blades and the shape of rolling pieces, the shearing machine can be divided into parallel blade shearing machines, inclined blade shearing machines, disc shearing machines and various types of clippers.

The two blades of the parallel blade cutter are parallel to each other and are characterized in that both cutting edges are in contact with the metal being sheared at the same time. The shearing process is completed in a short time, the shearing efficiency is high, and the shearing machine is subjected to large load. It is commonly used for transverse hot shearing of rolled blanks (squares, slabs) and other square and rectangular section billets.

The two blades of the oblique blade cutter are angled, generally, the blade is inclined and the lower blade is horizontal. These shears are commonly used for cold shearing and hot shearing of steel sheets, steel strips, thin slabs, welded tube blanks, and sometimes for cutting small steel product.

The blades of the disc shear are made into discs. There are two types of disc shears used in the rolling mill workshop: one for longitudinal shearing of steel sheets and strips; and one for cutting heads of small steel product or wire production. Their common feature is the completion of the shearing task during the running of the steel by rotating pairs of disc cutting edges.

Flying shears are mainly used for sharing moving rolling stock transversely. Flying shears are used in section steel production, billet production, and steel sheet production. The cutting task is completed during the running of the steel, and thus the running speed of the steel is required to be substantially the same as the peripheral speed of the cutting edge. Most of these shears are placed on the line of semi-continuous or continuous mills.

Recently, in order to solve the problem that the shearing load is large, the walking beam shearing machine has appeared. The shearing process of this type of shear is performed in stages. In the above-mentioned various types of shearing machines, the eccentric shaft rotates one turn or less than one turn to complete one shearing action, while the walking beam shearing machine rotates the eccentric shaft into several turns to complete a shearing action. The eccentricity of the eccentric shaft on the step shear is small (usually 5~10mm). The walking beam shearing machine uses a set of stepping mechanisms to continuously change the position of the table to complete the entire cutting process.

What Are The Requirements For Rolling Mills For Lubrication?

What Are The Requirements For Rolling Mills For Lubrication?

Rolling mills requirements for lubrication:

Grease lubrication: such as the input ramp of the furnace in the hot strip mill, the pusher, the discharger, the stand, the stand, the mill ramp, the mill work, the motor bearing, the mill press, the universal joint shaft Grease with bracket, cutting machine, looper, guide, output ramp, tumbling machine, coiler, washing machine, turning machine, shearing machine, disc cutter, edger, boring machine, etc. lubricating;

Lubricating oil adopts circulating lubrication: For example, Baosteel 2030 five-stand cold rolling mill is an example, strip steel cooling and lubricating emulsion system and oil feeding system uncoiler, five machines, feeding hoe, electric motor, rolling shear, guide, Lubrication of steering rollers and coilers, gear oils, leveling machines, etc., oil film bearing systems for each frame. Bearings for high-speed, high-precision rolling mills, lubricated with oil mist and oil and gas. 

Let’s talk about it in detail below:

Hot-rolled sheet steel strip mill requirements for grease:

Strip technology is the technology with the highest technical content and the highest added value of products in rolling steel production. In order to improve the shape and surface quality of the rolled products, most of the strip mills use CVC, bending rolls, nip rolls, and other world-class technologies. However, due to the harsh bearing conditions of such rolling mills, the selection of suitable greases is carried out. Lubrication is especially important.

Plate type rolling steel work roll housing high temperature: the billet temperature is above 1200 °C. During the rolling process, the radiant heat and conduction heat can make the work roll housing temperature reach 100 °C or above.

Heavy load: the rolling mill bearing is subject to a large rolling force and impact load, especially due to the joint action of the CVC rolling mill, the nip roller and the bending roller, the rolling force of the rolling mill bearing can be decomposed into the axial force and the radial force. The axial force is mainly caused by the roll (the roll is plus or minus 100 mm), and the radial force is mainly composed of the rolling force and the bending force (the bending force is 120 tons/roll neck).

Multi-water: During the rolling process, a large amount of spray water is required to cool the rolls, and the spray water can easily enter the bearing, especially the lower work rolls.

High speed: The billet has a high rolling speed in the finishing zone, and the wire speed of the F6 frame can be 13m/s. Rolling mill bearings require excellent high-temperature resistance: the thickener of the rolling mill bearing grease has high physical stability, does not melt or decompose at the ambient temperature used; the tendency of the grease to soften at high temperatures is small; Has good thermal reversibility. The lipid drop point should be greater than 250 ° C to ensure that it can be used in high-temperature environments. It also has good pumping performance at lower temperatures and a wider temperature range.

Excellent water resistance: the consistency of the rolling mill bearing grease should not be much lower after it is in contact with water or even mixed with water. It prevents the loss of lubricant and reduces the lubricity, and it still has good protection.

Excellent rust and corrosion resistance: The bearing grease of the rolling mill should be able to maintain good protection and lubricity in the water vapor and dust environment and prolong the life of the bearing.

Good extreme pressure and wear resistance: the rolling mill bearing grease should be able to withstand a large rolling force and impact load, especially under the joint force of CVC rolling mill, nip roller and bending roller, it can form a good oil film thickness.

What Is Cold Rolling Mill ?

What Is Cold Rolling Mill ?

What is cold rolling? I believe people who will be very interesting in "What is Cold Rolling"?  

If the temperature is below its recrystallization temperature when mental rolled, the process is called cold rolling. 

Cold rolling is fulfilled by making steel strip through plenty of tandem rolling mill stands. And each one of stands has vertically stacked rolls that are powered by a huge motor to impart high compressing stresses into the strip. 

Cold-rolling mills can produce various products like the smooth tin plates flowing like water, shiny galvanized plates glittering like mirror and other colorful coated sheets. They can then be pressed into cans or applied on industrial machines and household appliances or even just for decoration. 

What rolling mills do are not just limited to those plates. Rods, bars, wires, rails... You name it. All these productions can be easily achieved just like the plates with rollers in different shapes. 

With the emergence of new technologies in this field, it’s not hard for us to believe that the rolling mills in the future will be smarter and much more powerful. The application of those new technologies will lead us to cost reduction, quality insurance and the improvement of competitive abilities. 

What Are The Advantages Of Non-Twist Rolling Mill?

What Are The Advantages Of Non-Twist Rolling Mill?

What are the advantages of the non-twist rolling mill in the application?

Rolling mill is mainly for various products, but if you want to achieve good production results, then the type of mill you choose must be fully matched with all aspects, so the ability of ordinary rolling mill must be relatively limited, but after the improvement of the new equipment is different, such as the non-twist rolling mill ! No matter in the quality of the tied piece or the rolling efficiency, there are obvious improvements.

Understand what is the non-twist rolling mill?

What is a non-twist rolling mill, in fact, in the rolling mill set, the use of all-flat layout, effectively achieve the whole line of the non-twist rolling process, to put it simply, this rolling mill in the whole process of rolling, without any twist.

It is precisely because of these minor improvements that the utilization ratio of the rolling mill has been greatly improved, and the overall productivity of rolling mill has been increased. At the same time, the different defects that may occur during the twisting of the tie piece have been improved. The most important thing is to improve the rolling quality.

What is Hot Rolling?

What is Hot Rolling?

Rolling mill is a metalworking process which divided into two types: hot rolling and cold rolling. Here we will analyze the hot rolling cause we had discussed cold rolling before.

In many theory books, which called hot rolling is a metalworking process that occurs above the recrystallization temperature of the material. On the contrary, it means that below the recrystallization temperature of the metalworking process is called cold rolling.

But what is hot rolling besides of this word. Here we have the detail explanation about it. After the grains deform during processing, they recrystallize, which maintains an equiaxed microstructure and prevents the metal from work hardening. The starting material is usually large pieces of metal, like semi-finished casting products, such as slabs, blooms, and billets. If these products came from a continuous casting operation the products are usually fed directly into the rolling mills at the proper temperature. In smaller operations, the material starts at room temperature and must be heated. This is done in a gas- or oil-fired soaking pit for larger workpieces and for smaller workpieces induction heating is used. As the material is worked the temperature must be monitored to make sure it remains above the recrystallization temperature. To maintain a safety factor, finishing temperature is defined above the recrystallization temperature; this is usually 50 to 100 °C (90 to 180 °F) above the recrystallization temperature. If the temperature does drop below this temperature the material must be re-heated before more hot rolling. All of this above, just part of the hot rolling actually.

Hot rolled metals generally have little directionality in their mechanical properties and deformation induced residual stresses. However, in certain instances, non-metallic inclusions will impart some directionality and workpieces less than 20 mm (0.79 in) thick often have some directional properties. Also, non-uniformed cooling will induce a lot of residual stresses, which usually occurs in shapes that have a non-uniform cross-section, such as I-beams. While the finished product is of good quality, the surface is covered in mill scale, which is the forms at high temperatures. It is usually removed via pickling or the smooth clean surface; process, which reveals a smooth surface.  Dimensional tolerances are usually 2 to 5% of the overall dimension.

Hot rolled mill steel seems to have a wider tolerance for amount of included carbon than cold rolled, making it a bit more problematic to use as a blacksmith. Also for similar metals, hot rolled seems to typically be less costly.

Hot rolling is used mainly to produce sheet metal, rebar, wire rod or other products. In a words, hot rolling is very popular used in the steel industry.

Since 1989 Hani Tech has been always involved in design, engineering, manufacturing and installation of complete hot rolling mill plant for long products (re-bars, SBQ bars, wire rod, small and medium sections), as well as revamping and upgrading of existing plants. 

Hani Tech is the one-stop manufacturer & supplier able to design, manufacture, install and commission your hot rolling mill plant from A to Z.