1. Введение
Cold-rolled steel coils are essential materials for industries requiring tight dimensional control, excellent surface finish, and superior mechanical performance.
They serve as the foundation for products such as spring steel strips, stainless blades, автомобильные компоненты, and electronic parts.
В Цзясяо МТС, we specialize in manufacturing Высокий углерод, сплав, и полоски из нержавеющей стали through advanced cold-rolling processes.
Let’s explore how these coils are made — step by step — and what makes our products stand out in quality and consistency.
2. What Is Cold Rolling?
Cold rolling is a metalworking process in which hot-rolled steel is further reduced in thickness at room temperature using precision rollers.
Unlike hot rolling, which shapes steel while it’s red-hot, cold rolling enhances the dimensional accuracy, плоскостность, и surface brightness of the final product.
Key benefits include:
- Improved surface quality и appearance
- Higher предел текучести и твердость
- Точный thickness and width tolerances
- Better формуемость и elasticity
3. Step-by-Step Manufacturing Process
Step 1: Hot-Rolled Coil Pickling
The process begins with hot-rolled coils, which have a rough, oxidized surface after initial rolling.
These coils undergo acid pickling — removing scale and surface impurities using hydrochloric or sulfuric acid — leaving a clean steel surface ready for cold reduction.
Jiaxiao MTC uses continuous pickling lines that ensure a uniform, oxide-free surface, which is essential for consistent cold-rolling performance.
Step 2: Холодная прокатка
The cleaned coil is then processed in 4-high or 6-high cold-rolling mills.
Здесь, the material is compressed between hardened rollers to achieve the desired final thickness — often between 0.1 mm and 3.0 мм.
During this step:
- Thickness reduction can reach 50–90%, depending on the grade.
- Rolling pressure and speed are precisely controlled to avoid residual stress or deformation.
- The process increases the steel’s предел прочности и твердость.
Step 3: Отжиг (Softening Treatment)
Cold rolling increases hardness but reduces ductility, so the material must be отожженный to restore its formability.
Annealing involves heating the coil in a controlled atmosphere furnace to around 680–780 °C, then slowly cooling it to produce a uniform, soft microstructure.
В Цзясао МТЦ, bright annealing is performed in protective hydrogen or nitrogen atmospheres, preventing oxidation and giving the surface a bright metallic luster.
Step 4: Skin-Passing and Levelling
After annealing, the coils undergo skin-pass rolling — a light reduction process that improves flatness and controls surface texture.
This step ensures the coil has:
- Consistent mechanical properties
- Гладкий, uniform surface roughness
- Excellent dimensional accuracy
Step 5: Slitting and Edge Treatment
The annealed coils are slit into narrow strips using high-precision slitting machines.
Edges can be customized as:
- Slit edge (mill edge)
- Round edge
- Square edge
Jiaxiao MTC offers precision edge finishing for specific industrial requirements — for example, rounded edges for spring steel or flat edges for blade manufacturing.
Step 6: Отделка поверхности
Depending on customer needs, coils can receive surface treatments such as:
- Bright polished finish
- Matte finish
- Blue or yellow temper color
- Protective oil coating
These finishes enhance appearance, устойчивость к коррозии, and lubricity for downstream forming processes.
Step 7: Inspection and Packaging
Before shipment, each coil undergoes:
- Hardness and tensile tests
- Thickness and width measurements
- Surface inspection under magnification
Coils are then wrapped with anti-rust film, plastic layers, and steel bands, ensuring safe export packaging suitable for long-distance marine transport.
4. Jiaxiao MTC’s Cold-Rolling Advantages
| Особенность | Benefit |
|---|---|
| Advanced Cold-Rolling Mills | Achieve thickness tolerance ±0.015 mm |
| Bright Annealing Furnaces | Clean, oxidation-free surfaces |
| Full In-House Processing | From pickling to slitting and tempering |
| Flexible Material Range | C75S, 50КрВ4, СК5, 301, 420, и более |
| Strict Quality Control | ISO certified with 100% coil traceability |
| Export-Grade Packaging | Corrosion-resistant and seaworthy |
Through these technologies, Jiaxiao MTC ensures that every cold-rolled coil meets international mechanical, dimensional, and surface quality standards.
5. Applications of Cold-Rolled Steel Coils
Cold-rolled steel coils are widely used in:
- Automotive industry: seat belt parts, диски сцепления, and springs
- Construction tools: мастерки, лезвия, and saw strips
- Hardware manufacturing: прокладки, шайбы, ножки для обуви
- Precision components: electronic housings, instruments
Whether soft annealed or hardened and tempered, Jiaxiao MTC’s coils provide сила, гибкость, and consistency to critical applications worldwide.
6. Заключение
The cold-rolling process transforms raw hot-rolled steel into high-precision, high-performance coils that power modern industries.
With state-of-the-art rolling mills, annealing furnaces, and quality systems, Цзясяо МТС continues to deliver top-grade cold-rolled steel coils for global customers seeking долговечность, точность, и надежность.
