Cold Rolling

Cold Rolling: Rolling below the recrystallization temperature is called cold rolling. Usually hot rolled steel coils are used as raw material. After pickling, continuous cold rolling is performed to remove oxidation skin. The finished product is a hard rolled coil. Work hardening increases the strength and hardness of the rolled hard coil and decreases the toughness and plasticity index, so the punching performance decreases and it can only be used for parts with simple deformation. Hard rolled coils can be used as raw material for hot-dip galvanizing plants, since hot-dip galvanizing lines are equipped with annealing lines. The weight of hard rolled coils is usually 20-40 tons and the hot rolled pickled coils are continuously rolled at room temperature with an inner diameter of 610 mm.

Product characteristics: Due to the lack of annealing treatment, the hardness is very high (HRB over 90), the machinability is extremely poor, and only simple directional bending below 90 degrees (perpendicular to the winding direction) can be performed.

Simply put, cold-rolled is processed and rolled on the basis of hot-rolled coil, generally speaking, the process of hot rolling - pickling - phosphating - saponification - cold rolling, etc.

Cold rolling is made from hot rolled sheet at room temperature, although the temperature of the steel sheet is heated during the process, but it is also called cold rolling. Due to continuous cold deformation during hot rolling, the mechanical properties are relatively poor and the hardness is too high. It must be annealed to restore its mechanical properties, and the unannealed coil is called hard-rolled coil. Hard rolled coils are typically used for products that do not require bending or stretching and are bent on both sides or all four sides at a thickness of 1.0 or less.

Additional correction: Cold rolled is usually annealed.

Cold rolling oil must be used in the cold rolling process. Advantages of using cold rolling oil.

1、effectively reduce the coefficient of friction, to ensure the appropriate rolling force, low energy consumption of rolling, to obtain satisfactory rolling parameters.

2、Make the surface brightness high and rolling thickness uniform.

3、good cooling effect, rolling heat can be quickly dissipated to protect the rolls and workpiece. Good annealing performance, no oil burning phenomenon.

4、with short-term anti-corrosion performance, can provide temporary anti-rust protection for rolled products.

Hot rolling

Hot rolling refers to cold rolling, cold rolling refers to rolling below recrystallization temperature and hot rolling refers to rolling above recrystallization temperature.

Advantages: it can destroy the casting organization of the ingot, refine the grain of steel, eliminate microstructural defects, make the steel organization more dense and improve the mechanical properties. This improvement is mainly reflected in the rolling direction, so that the steel is no longer isotropic to a certain extent; bubbles, cracks and pores formed during the casting process can also be welded at high temperature and pressure.

Cold Rolling

Cold Rolling: Rolling that takes place below the recrystallization temperature is called cold rolling. Hot rolled steel coils are usually used as raw material. After pickling, continuous cold rolling is carried out to remove oxidation skin. The finished product is a rigid roll. Work hardening increases the strength and hardness of the rolled rigid steel coil and reduces the toughness and ductility index, so the punching performance is reduced and it can only be used for parts with simple deformation. Hard rolled coils can be used as raw material for hot-dip galvanizing plants, since hot-dip galvanizing lines are equipped with annealing lines. The weight of hard rolled coils is usually 20-40 tons and hot rolled pickled coils are rolled continuously at room temperature. Inner diameter 610 mm.

Product characteristics: High hardness (HRB over 90) due to the lack of annealing treatment, very poor workability and only simple directional bending below 90 degrees (perpendicular to the winding direction).

In simple terms, cold rolling is processing rolling on the basis of hot rolled coils, which is generally hot rolling - pickling - phosphating - saponification - cold rolling and other processes.

Cold rolling is made from hot rolled sheet at room temperature, although the temperature of the steel sheet is heated during the process, but it is also called cold rolling. Due to continuous cold deformation during hot rolling, the mechanical properties are relatively poor and the hardness is too high. It must be annealed to restore its mechanical properties, and the unannealed coil is called hard-rolled. Hard rolled coils are typically used for products that do not require bending or stretching and are double or quadruple folded at a thickness of 1.0 or less.

Additional correction: Cold-rolled steel is usually annealed.

Cold rolling must be done with cold rolling oil. Benefits of using cold rolling oil.

1、Effective reduction of friction coefficient to ensure proper rolling force, low rolling energy consumption and satisfactory rolling parameters.

2、high surface brightness and uniform rolling thickness.

3、good cooling effect, rolling heat can be quickly dissipated to protect the rolls and workpiece. Good annealing performance, no oil burning phenomenon.

4、with short-term anti-corrosion performance, which can provide temporary rust protection for steel.

Hot rolling

Hot rolling refers to cold rolling, cold rolling refers to rolling below recrystallization temperature, hot rolling refers to rolling above recrystallization temperature.

Advantages: It can destroy the casting organization of the ingot, refine the steel grain, eliminate tissue defects, make the steel organization more dense and improve the mechanical properties. This improvement is mainly reflected in the rolling direction, so that the steel is no longer isotropic to a certain extent; bubbles, cracks and pores generated during the casting process can also be welded under high temperature and pressure. (Imported mold steel)