Cold-rolled stainless steel

2025-03-25

The difference between cold rolled steel and hot rolled steel

In the field of steel processing, cold-rolled steel and hot-rolled steel are two common product types. They have significant differences in production process, performance characteristics and application fields. Understanding the difference between cold-rolled and hot-rolled steel can help us better choose the right material for our specific needs. In this paper, the differences between cold-rolled steel and hot-rolled steel will be analyzed in detail from three aspects: production process, performance characteristics and application fields.
The difference of production process
1. Production process of hot rolled steel
Hot rolled steel is processed by a rolling mill under high temperature conditions (usually above the recrystallization temperature). The billets are heated to high temperatures in a heating furnace and then formed by roughing and finishing rolling processes. This high temperature treatment makes the steel easy to form, while also reducing internal defects.
2. Production process of cold rolled steel
Cold rolled steel is made by further processing hot rolled steel plates at room temperature. After pickling to remove the oxide, the hot-rolled steel sheet is fed to a cold mill for multiple calendering, resulting in a more precise thickness and a smoother surface. The cold rolling process usually requires more processing steps and is therefore more expensive.
The difference in performance characteristics
1. Performance characteristics of hot rolled steel
- Surface quality: Due to the possibility of forming oxide skin on the surface during hot rolling, the surface roughness is large and the finish is low.
- Dimensional accuracy: Due to the expansion and contraction of the material caused by high temperature, the dimensional accuracy of hot-rolled steel is relatively low.
- Strength and toughness: hot-rolled steel has good toughness and ductility, but relatively low strength.
- Internal structure: the grain size is large during the hot rolling process, and the internal structure uniformity is poor.
2. Performance characteristics of cold rolled steel
- Surface quality: The surface of cold rolled steel is smooth and smooth, high finish, suitable for occasions with high appearance requirements.
- Dimensional accuracy: Due to the precise control of thickness in the cold rolling process, the dimensional accuracy of cold rolled steel is high.
- Strength and hardness: The cold rolling process will cause a certain amount of work hardening of the material, so the strength and hardness of cold-rolled steel are high, but the toughness is relatively low.
- Internal organization: After cold processing, the internal grain of the material is refined and the performance is more stable.
Differences in application fields
1. Application of hot rolled steel
Because of its low cost and good toughness, hot rolled steel is widely used in occasions requiring greater pressure or for secondary processing, such as:
- Building structure: such as Bridges, building frames, steel rails, etc.
- Pipeline manufacturing: suitable for transporting liquid or gas pipelines.
- Heavy machinery: such as ships, car chassis, etc.
2. Application of cold rolled steel
Because of its high surface quality and good dimensional accuracy, cold-rolled steel is more suitable for occasions with high appearance and precision requirements, such as:
- Home appliance manufacturing: such as refrigerator, washing machine shell, etc.
- Automotive industry: for body coverings and internal components.
- Precision instruments: suitable for small parts requiring high strength and precision.
How to choose the right material?
When choosing cold-rolled or hot-rolled steel, the following factors should be considered according to the specific needs:
1. Budget: If cost is the main consideration, hot rolled steel can be preferred.
2. Appearance requirements: When the surface finish is required, cold rolled steel should be selected.
3. Strength and toughness: hot rolled steel is suitable for occasions requiring high toughness, and cold rolled steel is selected when high strength and hardness are required.
4. Processing requirements: If complex processing or coating treatment is required in the future, cold-rolled steel may be more suitable.

	Hot rolling of stainless steel	Cold rolling of stainless steel
Process	The steel billet is heated to a high temperature (about 1100°C or above) and then rolled, and then cooled naturally	After the hot-rolled coil is pickled to remove the oxide scale, it is further rolled at room temperature
Surface quality	The surface is rough, there may be oxide scale or slight bumps	The surface is smooth, delicate, without oxide scale, and can be polished to a mirror effect
Dimensional accuracy	The thickness tolerance is large (±0.1-0.2mm)	The thickness tolerance is small (±0.01-0.05mm), and the size is more accurate
Mechanical properties	Low strength, good ductility, low hardness	High strength, high hardness (work hardening effect), slightly poor ductility
Thickness range	Usually ≥3mm (mainly medium and thick plates)	Usually ≤3mm (thin plates and foils can reach less than 0.1mm)
Common materials	304, 316, 201, 430, etc.	304, 316L, 301, 430, etc.
Cost	Low energy consumption, low production cost	Complex process (pickling + cold rolling + annealing), high cost
Typical applications	Chemical storage tanks, building structures, industrial equipment, ship parts	Precision instruments, electronic products, decorative panels, medical equipment, tableware
Subsequent processing	Pickling or sandblasting is required before welding/spraying	Can be directly electroplated, sprayed or further stamped

Advantages of cold rolled steel

Cold rolled steel is a kind of steel made by cold rolling process, which is widely used in many fields such as construction, automobile, home appliance and machinery manufacturing. Compared with hot-rolled steel, cold-rolled steel has many significant advantages, making it occupy an important position in industrial production and daily life. This article will introduce the main advantages of cold rolled steel in detail.
1. High precision and excellent surface quality
The production process of cold-rolled steel is carried out at room temperature, which makes its dimensional accuracy very high. The thickness error of the cold-rolled steel plate can usually be controlled within a very small range to meet the needs of the industry for high-precision materials. In addition, the surface of cold-rolled steel is smooth and flat, no oxide skin, and the appearance quality is excellent, which is ideal for application scenarios requiring high surface quality, such as home appliance housings and automotive parts.
2. Excellent mechanical properties
Through the cold rolling process, the strength and hardness of the steel are significantly increased, while its toughness and plasticity are also maintained or optimized. This improvement in performance allows cold-rolled steel to withstand greater mechanical pressure and is suitable for structural parts requiring high strength and durability. In addition, cold-rolled steel also has good formability in subsequent processing, and can be complex bending, stamping and other processing.
3. High material utilization rate
Cold-rolled steel is usually supplied in coil or sheet form, and its size and shape can be flexibly customized according to demand. This characteristic reduces the waste of materials and improves the utilization rate of materials. At the same time, due to its high precision and stability, the use of cold-rolled steel can reduce errors in subsequent processing processes, thus further saving costs.
4. Easy to coat and electroplate
Cold rolled steel has a smooth, flat surface with no oxide or impurities, making it ideal for coating and electroplating. Whether it is anti-corrosion coating or decorative coating, cold-rolled steel can be well attached to ensure the uniformity and beauty of the coating. This makes cold-rolled steel widely used in the field of home appliances, furniture and decorative materials.
5. Environmental protection and sustainability
The cold rolling process uses less energy than the hot rolling process and can effectively reduce material waste due to its high precision and high utilization rate. This not only reduces production costs, but also reduces environmental impact. In addition, as a recyclable material, cold-rolled steel also meets the requirements of modern industry for sustainable development.
6. Wide range of applications
Cold rolled steel is widely used in many industries because of its excellent properties. For example, in the automotive industry, cold-rolled steel is used to make body structures and cladding; In the construction industry, it is used to make roof panels, wall panels and other building components; In the home appliance industry, cold-rolled steel is widely used in the shell production of refrigerators, washing machines and other equipment.