كيف تؤثر مادة أسطوانة مصنع الدرفلة على أدائها وعمرها التشغيلي؟

Roller material has a significant impact on performance and life. Hardness determines wear resistance, and high-hardness materials can reduce wear; strength is related to fatigue resistance, and high-strength materials can withstand rolling forces and alternating stresses; toughness affects impact resistance; heat-resistant and corrosion-resistant materials are suitable for high temperatures and harsh environments.

Hardness and wear resistance

High hardness material

• The hardness of the roll material determines its ability to resist wear. For example, a roll made of high-chromium cast iron has a high chromium content and can form hard carbides with a hardness of 60-70HRC (Rockwell hardness).During the rolling process, this high-hardness roll can effectively resist friction and wear on the surface of the rolled material. When rolling metal sheets, high-hardness rolls can maintain a good surface profile, reduce wear on the roll surface, and thus extend service life.
• Carbide rolls are another type of roll material with a very high hardness, with a hardness of up to 80-90HRC. This type of roll is often used for cold rolling of high-precision thin plate materials, such as copper foil and aluminum foil rolling in the electronics industry. Due to the high hardness of cemented carbide, it can maintain surface accuracy during a long rolling process, making the rolled foil material uniform in thickness and high in surface quality.

Hardness and wear mechanisms

• When the roll hardness is low, adhesive wear is more likely to occur during the rolling process. For example, during the hot strip rolling process, if the roll hardness is insufficient, the hot steel strip may adhere to the roll surface, causing the roll surface material to be torn and causing wear. High-hardness rolls can reduce this wear by reducing the tendency to adhere.
• Harder rolls also have better resistance to abrasive wear. When rolling metal materials containing hard inclusions, such as some alloy steels containing hard oxide particles, these inclusions will scratch the roll surface like abrasive particles. High-hardness rolls can withstand this scratching, while lower-hardness rolls will scratch and wear more quickly.

Strength and fatigue resistance

High strength material

• The strength of the roll is crucial to withstand the rolling force. Alloy steel rolls have high strength and can withstand huge rolling pressure. For example, in the rolling process of large steel sections, the rolls need to withstand tens of thousands of tons of rolling force. High-strength alloy steel materials, such as 42CrMo, have high yield strength and can prevent the rolls from plastic deformation under high pressure.
• Forged rolls usually have better strength than cast rolls. The forging process makes the internal structure of the material denser, which can effectively improve the roll’s resistance to fracture. For example, in the process of continuously rolling high-precision thin plates, forged cold rolling work rolls can withstand frequent alternating stresses and are not prone to cracks and fractures.

Fatigue failure mechanism

• Rollers are subjected to alternating stress during repeated rolling. If the material has poor fatigue resistance, fatigue cracks are likely to form on the surface or inside the roll.For example, during high-speed cold rolling, the roll may be subjected to hundreds of rolling cycles per minute. When the fatigue strength of the material is insufficient, these cracks will gradually expand and eventually lead to roll failure. Materials with good fatigue resistance, such as roll materials that have undergone special heat treatment, can improve the fatigue limit and extend the service life of the roll by refining the grains and eliminating internal stress.

Toughness and impact resistance

High toughness material

• Roller materials with good toughness can absorb energy and avoid cracking when impacted. For example, when rolling some irregularly shaped metal billets or when there are sudden impacts during the rolling process (such as local stress concentration caused by uneven billet temperature), ductile iron rolls with high toughness can effectively resist the impact. The spherical graphite in ductile iron can make the material deform to a certain extent without breaking when impacted, thereby protecting the rolls.
• Composite rollers are also an option to improve toughness. For example, the outer layer of the roller is made of high-hardness wear-resistant material, and the inner layer is made of high-toughness support material. This structure can improve the overall impact resistance of the roller while maintaining good wear resistance.

Impact damage effects

• When a roll is damaged by impact, its surface quality and dimensional accuracy will be seriously affected. For example, cracks or partial damage on the roll surface will cause defects on the rolled material surface during the rolling process, such as dents and scratches. Moreover, once the roll is damaged by impact, these damaged parts will become stress concentration points, accelerating further damage to the roll and greatly shortening its service life.

Heat and corrosion resistance

Heat-resistant material

• In the hot rolling process, the rolls need to withstand high temperatures. Rollers made of heat-resistant steel, such as those containing alloying elements such as chromium and nickel, can maintain good mechanical properties at high temperatures. For example, in the rough rolling stage of hot-rolled steel plates, the roll temperature may reach 500-600℃. Heat-resistant steel rolls do not soften at such high temperatures, allowing stable rolling operations.
• Ceramic rolls have excellent heat resistance. For example, silicon carbide ceramic rolls can work at higher temperatures, and their high temperature resistance can reach over 1000°C. This type of roll plays an important role in the high-temperature rolling of special metals or the rolling of some heat-treated metal materials.

Corrosion-resistant material

• For rollers working in harsh environments, such as rolling some corrosive metals (such as pickled strip steel), the corrosion resistance of the material is very important.Stainless steel rollers have good corrosion resistance. The chromium element they contain can form a dense oxide film on the surface of the roller to prevent the erosion of corrosive media. For example, in the process of cold rolling stainless steel strips, the use of stainless steel rollers can prevent the rollers from being corroded by corrosive substances on the surface of the steel strip, extending the service life of the rollers.
• Some surface coatings can also improve the corrosion resistance of the rolls. For example, a ceramic coating or anti-corrosion paint is applied to the surface of the roll. These coatings can act as a physical or chemical barrier to prevent corrosive substances from contacting the roll base material, thereby protecting the roll and increasing its service life in a corrosive environment.