Most steel processing involves pressure processing, causing plastic deformation of the steel (billets, ingots, etc.). Based on the processing temperature, it can be divided into cold working and hot working.

According to a report in February 2025, steel production in 2024 reached 1,399.674 million tons, an increase of 1.1% over the previous year.

Production

1. Smelting methods: converter steelmaking, open-hearth steelmaking, electric arc furnace steelmaking

2. Deoxidation and ingot casting: Depending on the degree of deoxidation, rimmed steel, killed steel, and semi-killed steel can be produced.

3. Hot working

Feature

Ferrous Metals

Ferrous metals mainly refer to iron, manganese, chromium, and their alloys.

Steel

Steel is obtained by smelting pig iron in a steelmaking furnace according to a certain process.

Non-ferrous metals

Metals other than ferrous metals are called non-ferrous metals, such as copper, tin, lead, zinc, aluminum, as well as brass, bronze, aluminum alloys, and bearing alloys.

Classification

Finished Materials

Building Materials – Rebar, Wire Rod, Coiled Rebar, Round Bar

Pipes – Seamless Pipes, Welded Pipes

Plate Materials – Cold-rolled and Hot-rolled Plates/Coils, Medium and Heavy Plates, Color-coated Plates (Galvanized Plate, Color-coated Plate, Tinplate, Aluminized Zinc-coated Steel Plate), Silicon Steel, Strip Steel

Profiles – I-beams, Angle Beams, Channel Beams, H-beams, Square Steel, Flat Steel, Ball Flat Steel

Special steel

This includes structural steel, tool steel, die steel, spring steel, bearing steel, cold heading steel, and hard wire.

Steel is an iron-carbon alloy with a carbon content between 0.0218% and 2.11%. To ensure its toughness and plasticity, the carbon content generally does not exceed 1.7%. Besides iron and carbon, the main elements in steel include silicon, manganese, sulfur, and phosphorus. There are various ways to classify steel, the main methods being the following five:Steel is an iron-carbon alloy with a carbon content between 0.0218% and 2.11%. To ensure its toughness and plasticity, the carbon content generally does not exceed 1.7%. Besides iron and carbon, the main elements in steel include silicon, manganese, sulfur, and phosphorus. There are various ways to classify steel, the main methods being the following five:

1. Classification by Quality:

Ordinary steel: (P≤0.045%, S≤0.050%);

High-quality steel: (P, S≤0.035%);

High-grade high-quality steel: (P≤0.035%, S≤0.030%).

2. Classification by Chemical Composition:

Carbon steel:

a. Low-carbon steel (C≤0.25%);

b. Medium-carbon steel (0.25≤C≤0.60%);

c. High-carbon steel (C≥0.60%). 1. Low-alloy steel (total alloy element content < 5%); b. Medium-alloy steel (5% ≤ total alloy element content ≤ 10%); c. High-alloy steel (total alloy element content > 10%).

3. Classification by forming method: (1) Forged steel; (2) Cast steel; (3) Hot-rolled steel; (4) Cold-drawn steel.

4. Classification by metallographic structure: Annealed state: a. Hypoeutectoid steel (ferrite + pearlite); b. Eutectoid steel (pearlite); c. Hypereutectoid steel (pearlite + cementite); d. Ledeburite steel (pearlite + cementite).

Normalized state: a. Pearlitic steel; b. Bainitic steel; c. Martensitic steel; d. Austenitic steel. (3) No phase transformation or partial phase transformation.

5. Classification by application: Engineering steel: a. Ordinary carbon structural steel; b. Low-alloy structural steel; c. Reinforcing steel. Carburizing steel: a. Nitriding steel; b. Surface hardening steel; c. Free-cutting structural steel; d. Cold forming steel: including cold stamping steel and cold heading steel.

Carbon tool steel: a. Alloy tool steel; b. High-speed tool steel.

Special performance steel: a. Stainless and acid-resistant steel; b. Heat-resistant steel: including oxidation-resistant steel, heat-resistant steel, and valve steel; c. Electrothermal alloy steel; d. Wear-resistant steel; e. Low-temperature steel; f. Electrical steel.

Bridge steel, shipbuilding steel, boiler steel, pressure vessel steel, agricultural machinery steel, etc.

6. Comprehensive Classification

High-quality steel

1. Structural Steel: (a) High-quality carbon structural steel; (b) Alloy structural steel; (c) Spring steel; (d) Free-cutting steel; (e) Bearing steel; (f) Special purpose high-quality structural steel.

2. Tool Steel: (a) Carbon tool steel; (b) Alloy tool steel; (c) High-speed tool steel.

3. Special Performance Steel: (a) Stainless and acid-resistant steel; (b) Heat-resistant steel; (c) Electrothermal alloy steel; (d) Electrical steel; (e) High-manganese wear-resistant steel.

Nature

1. Tensile strength

2. Elastic modulus

3. Plasticity

4. Impact toughness, cold brittleness

5. Hardness

6. Cold bending performance

7. Weldability

8. Heat treatment

9. Cold working and aging

Quality Inspection

There are many quality inspection items for steel materials and steel components, including tensile testing, bending fatigue testing, compressive/flexural strength testing, and corrosion resistance testing. Real-time monitoring of product quality and performance during the research and development and production processes of materials and related products can prevent returns and waste of raw materials due to quality issues.

Classification by use

Structural Steel

(1) Structural steel for construction and engineering, also known as construction steel, refers to steel used in the manufacture of metal structural components for buildings, bridges, ships, boilers, or other engineering projects. Examples include carbon structural steel, low-alloy steel, and reinforcing steel.

(2) Structural steel for machinery manufacturing refers to steel used in the manufacture of structural parts for mechanical equipment. This type of steel is generally high-quality steel or high-grade high-quality steel, mainly including high-quality carbon structural steel, alloy structural steel, free-cutting structural steel, spring steel, and rolling bearing steel.

1. Tool Steel

Generally used for manufacturing various tools, such as carbon tool steel, alloy tool steel, and high-speed tool steel. According to their application, they can be further divided into cutting tool steel, mold steel, and measuring tool steel.

2. Special Steel

Steel with special properties, such as stainless acid-resistant steel, heat-resistant and non-scaling steel, high-resistance alloys, wear-resistant steel, and magnetic steel. 1. Specialty Steels

This refers to steels used for specific industrial applications, such as steel for automobiles, agricultural machinery, aerospace, chemical machinery, boilers, electrical engineering, and welding electrodes.

Based on steel quality: High-quality carbon structural steel, alloy structural steel, carbon tool steel and alloy tool steel, spring steel, bearing steel, etc. 

Steel grades are usually followed by the symbol "A" or the Chinese character "高" (high) for identification.

3.Specialty Steels

This refers to steels used for specific purposes in various industrial sectors, such as steel for automobiles, agricultural machinery, aviation, chemical machinery, boilers, electrical equipment, and welding electrodes.

According to the quality of steel

High-quality carbon structural steel, alloy structural steel, carbon tool steel and alloy tool steel, spring steel, bearing steel, etc.

The steel grade is usually followed by the symbol "A" or the Chinese character "高" for identification.

Size and weight

• Steel length dimensions

1. Standardized length for steel is an effective measure to save materials. Standardized length means that the length or width multiplied by a certain dimension is not less than a certain size, or that the length or width multiplied by a certain range is provided for delivery. Production units can then produce and supply according to these size requirements.

2. Variable length (normal length): Products with dimensions (length or width) within the standard range but not requiring a fixed size are called variable length. Variable length is also called normal length (standard length). Metal materials delivered in variable length only need to be delivered within the specified length range. For example, for ordinary round steel not exceeding 25mm, the normal length is specified as 4-10m; round steel within this length range can be delivered.

3. Fixed length: Steel cut to a fixed size according to order requirements is called fixed length. When delivering according to fixed length, the delivered metal materials must have the length specified by the buyer in the order contract. For example, if the contract specifies delivery in a fixed length of 5m, then the delivered materials must all be 5m long; materials shorter or longer than 5m are considered unqualified. However, in reality, it is impossible for all deliveries to be 5m long. Therefore, it is stipulated that positive deviations are allowed, but negative deviations are not.

• Length dimensions of structural steel

1. Standard lengths for railway tracks are 12.5m and 25m.

2. The dimensions of round steel, wire rod, and steel wire are specified in millimeters (mm) for diameter d.

3. The dimensions of square steel are specified in millimeters (mm) for side length a.

4. The dimensions of hexagonal and octagonal steel are specified in millimeters (mm) for the distance s between opposite sides.

5. The dimensions of flat steel are specified in millimeters (mm) for width b and thickness d.

6. The dimensions of I-beams and channel steel are specified in millimeters (mm) for web height h, flange width b, and web thickness d.

7. The dimensions of equal-sided angle steel are specified in millimeters (mm) for equal side width b and side thickness d. The dimensions of unequal-sided angle steel are specified in millimeters (mm) for side width B, b, and side thickness d.

8. The dimensions of H-beams are specified in millimeters (mm) for web height h, flange width b, web thickness t1, and flange thickness t2.

• Length dimensions of steel plates and strip(1) Steel plates are generally specified by their thickness d in millimeters (mm). Steel strips, on the other hand, are specified by their width b and thickness d in millimeters (mm).

     (2) Single steel plates have different specified dimensions. For example, hot-rolled steel plates with a thickness of 1mm are available in the following sizes: 600mm wide × 2000mm long; 650mm × 2000mm; 700mm × 1420mm; 750mm × 1500mm; 900mm × 1800mm; 1000mm × 2000mm, etc.

• Length dimensions of steel pipe

  (1) Generally, steel pipes are specified by their outer diameter (D), inner diameter, and wall thickness (S) in millimeters (mm).

  (2) Each type of steel pipe has different specified dimensions. For example, seamless steel pipes with an outer diameter of 50mm have 15 different wall thicknesses ranging from 2.5mm to 10mm; or, for the same wall thickness of 5mm, there are 29 different outer diameters ranging from 32mm to 195mm. Similarly, welded steel pipes with a nominal diameter of 25mm have ordinary steel pipes with a wall thickness of 3.25mm and thickened steel pipes with a wall thickness of 4mm.

• Steel weight

1. Theoretical Weight of Steel: The theoretical weight of steel is calculated based on its nominal dimensions and density (formerly known as specific gravity). This is directly related to the steel's length, cross-sectional area, and dimensional tolerances. Due to allowable deviations during the manufacturing process, the theoretical weight calculated using the formula will differ somewhat from the actual weight; therefore, it should only be used as a reference for estimation.

2. Actual Weight of Steel: The actual weight of steel refers to the weight obtained by actually weighing (weighing) the steel. The actual weight is more accurate than the theoretical weight.