In the rolling process, pairs of rolls are placed together in rolling mills so that they can turn steel and metals into products such as rails, structural steel, etc. at high speed. In most steel factories, there are rolling mills that turn semi-finished steel into final products.
Types of alloy processes are:
Bending rolling
Sectional rolling
Ring rolling
Controlled alloys
Rolling forming and...
Types of rolling
Hot rolling
The hot rolling metalworking process is performed at temperatures higher than the material's recrystallization temperature. In the next step, in order to maintain the equational microstructure and prevent the hardening of the metalwork after the deformation of the grains during processing, they are recrystallized. Raw materials in this process include large pieces of metal and semi-finished casting products.
During the rolling operation, the temperature should be controlled to know that its temperature remains above the recrystallization temperature. To maintain the safety factor, the final temperature is defined as higher than the recrystallization temperature. If the temperature drops below this, they must be reheated before hotter rolling.
Compared to cold rolling, hot rolling has a higher resistance to carbon, which is why it is more difficult to use it in forging. It has a lower cost for similar hot rolled metals. This method is used to produce simple sections such as railway tracks and metal sheets. Applications of hot rolled metal include:
Metal buildings
disks
Agricultural equipment
Guard rails for streets and highways
Compressor shells
Car wheel, rim and clutch plate
water heater
Pipe
Railway hopper machine and rail car components and...
Cold rolling
Cold rolling is a process during which the metal at lower temperatures It passes the recrystallization temperature through rollers. The metal is compressed and compressed, increasing the yield strength and hardness of the metal. The purpose of this process is to create thinner metal strips with good dimensional accuracy and specific surface quality for various applications. This process includes rods, strips and sheets. Also, cold rolled products are smaller than hot rolled products. Four-story or cluster mills are used due to the smaller size of the parts and their better resistance to hot rolling. In cold rolling, the thickness of the workpiece cannot be reduced as much as in hot rolling. Cold rolled strips and sheets are available in various conditions such as skin-faced, hard, semi-hard and quarter-hard. In hard rolling, 50% thickness reduction is done, but in other cases it is less. Also, skin coating rolling reduces the thickness by 0.5 to 1%, which is used to eliminate spangles in galvanized steel and produce a smooth and uniform surface. If the surface of the sections is almost uniform and its transverse dimension is relatively small, they can be rolled. Cold rolling shapes require forming operations. Rolling by a blacksmith produces a more consistent, smoother surface, but costs more. The applications of cold rolling steel are: Motorcycle exhaust pipes Cabinets Pipe metal dishes Lawn mower Home Appliances And...