Friday, July 26, 2019

The Adjustment of Steel Rolling Mill

steel rollong mill

Before the steel rolling mill is used, the roll pass, controlling plate shape and backup roll should be adjusted according to the requirement; and the fixed position of the rolls in the rolling mill should be maintained. The workload of the roll bearing is heavy and varies greatly, so the friction coefficient of the bearing is required to be small.

After determining the product rolled by the rolling mill, the line speed of the rolling mill can be basically determined. The hardness of the raw materials is measurable. The rolling stock of the rolling mill is determined by changing the plastic deformation size.
Usually, the newly installed steel rolling mill has a running-in process. During the running-in process, the rolls are operated in a second operation, and the operation speed is 50%, 65%, 75%, and 85%. Different steel rolling mill models use the rolls with different materials and specifications for different rolling products.


After the steel rolling mill is installed, the gears of the reducer and the gearbox need to have meshed, the rolling speed is too fast, and the torque is enhanced. After the normal operation of the rolling mill for 30 days, stop the rolling mill and check the meshing of the large and small gears, and waits for everything to be normal, the rolling speed can be increased.


Under normal circumstances, it is not necessary to adjust the rolling speed. The rolls in the steel rolling mill is constantly worn during the running process. In order to keep the rolling mill stable in the controlled rolling requirements, the roll must be repaired in time, and the rolls need to be replaced in serious cases.


The steel rolling mill needs labor, even the automated equipment needs to be monitored manually in the console. The conveyor roller and shearing machine located in the automatic rolling mill must be strictly controlled during operation to avoid the failure of stacking steel or jamming. If the wear of roll and guide exceeds the specified range, it needs to be replaced. 

The rolling of the billet causes the roll to be squeezed instantaneously, and the bearing is subjected to correspondingly high pressure, thereby affecting the product size of the rolled steel. We may also need to make in-depth improvements, but the ultimate goal is to get better steel rolling mill equipment.


We can supply rebar rolling mill and wire rod mill equipment designing, manufacturing, installation, and commission of the equipment with “turn-key” service.

We can also design, manufacture and revamp other non-standard equipment according to the requirements of users.


If interested, please mail at marketing2@hanrm.com or kerrirollingmill@gmail.com.

Tuesday, July 23, 2019

How to Package Steel?

Steel should be packaged according to national standards and contracting requirements. In general, the contents of the package are (except for special requirements in the contract):

(1) Profiled steel with a diameter or thickness of less than 30 mm and a thin plate with a thickness of less than 4 mm shall be delivered in bundles. Each bundle shall be of the same batch number, and each bundle shall be affixed with at least two signs. The nameplate shall indicate the manufacturer's name, steel number, furnace (can) number, specifications, etc.

(2) Steels with a diameter or thickness equal to or greater than 30 mm may be delivered in bundles or may not be delivered in bundles. For bundles of steel, each bundle shall be affixed with at least two signs, steel may not be stamped. Bundles of steel that do not carry signs should be stamped or marked on the top steel or plate of each bundle. Steel that is not bundled must be stamped on each steel or steel plate.

(3) After the steel is packaged (or not supplied in bundles), it shall be painted according to the relevant standards.

(4) Steel delivered in bundles, each bundle shall be bundled with wire at not less than two places.

(5) The weight of each bundle shall not exceed 80kg when manually loaded and unloaded, and shall not exceed 5t when mechanically loaded and unloaded. After the consent of the purchaser, the manual loading and unloading may not exceed 130kg per bundle, and the mechanical loading and unloading may not exceed 10t per bundle.

In order to facilitate the distinction and use, all kinds of steel should have the mark, that is, the stamp.

The stamp shall be applied to the end face of the steel or to the surface of the steel 100 mm from the end of the steel. The contents include steel grade, furnace number, tank number, spindle number, section number, etc. For steel stamps with a diameter or side length greater than 40 mm, it can be punched on the end face. For steel stamps with a diameter or side length of less than 40 mm, it can be hit on the end face, or on an iron plate, and the iron plate is hung on the steel.

We can supply rebar rolling mill and wire rod mill equipment designing, manufacturing, installation, and commission of the equipment with “turn-key” service.

We can also design, manufacture and revamp other non-standard equipment according to the requirements of users.

If interested, please mail at marketing2@hanrm.com.


Thursday, July 18, 2019

Hot Rolling Principle of Rolling Mill

Hot rolling is based on slabs (mainly continuous casting billets), which are heated to form strips by roughing rolling mills and finishing rolling mills. The hot steel strip from the last rolling mill of the finishing mill is cooled to a set temperature by laminar flow, rolled into a steel coil by a coiler, and the cooled steel coil is subjected to different finishing operations according to different needs of users. Lines (flat, straight, cross-cut or slit, inspection, weighing, packaging and marking) are processed into steel, flat and slit steel strips.

Since hot-rolled steel sheet products have high strength, good toughness, easy processing and good weldability, they are widely used in shipbuilding, automobiles, bridges, construction, machinery, pressure vessels and other manufacturing industries.
With the increasing maturity of new technologies such as hot-rolling dimensional accuracy, plate shape and surface quality, and the advent of new products, hot-rolled steel sheets and strip products have become more and more widely used and are becoming more and more competitive in the market. Hot rolling steel products can be divided into ordinary carbon structural steel, low alloy steel, alloy steel according to its material and performance.
     
According to the use, hot-rolled products can be divided into cold forming steel, structural steel, automobile structural steel, corrosion-resistant structural steel, mechanical structural steel, a welded gas cylinder and pressure vessel steel, and pipeline steel.
The advantage of hot rolling is that it can eliminate certain defects in the cast metal, such as welding the pores, refining coarse grains and changing the distribution of inclusions. The compactness and mechanical properties of the metal are improved. Secondly, the raw material (steel ingot or billet) is increased in thermoplasticity, and the deformation resistance is lowered. Therefore, the amount of deformation can be increased during rolling, which is advantageous for improving productivity. In addition, due to the reduced metal deformation resistance, the requirements for the rolling equipment can be correspondingly lower, so that the cost of the equipment can be reduced and the energy consumption of the motor can be greatly reduced.  

The disadvantage of hot rolling is that high-temperature rolling produces iron oxide scale so that the surface of the metal is not smooth and clean; the size of the product is not accurate enough, and the mechanical properties are not as good as cold working.

We can supply high-speed wire rod mill equipment designing, manufacturing, installation, and commission of the equipment with “turn-key” service.
We can also design, manufacture and revamp other non-standard equipment according to the requirements of users.

If interested, please mail at marketing2@hanrm.com.



Four Processes of High-speed Steel Manufacturing

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