Including structural steel, tool steel, die steel, spring steel, bearing steel, cold heading steel, hard wire
Steel is an iron-carbon alloy with a carbon content between 0.0218% and 2.11%. In order to ensure its toughness and plasticity, the carbon content generally does not exceed 1.7%. In addition to iron and carbon, the main elements of steel include silicon, manganese, sulfur and phosphorus. There are various classification methods of steel, and the main methods are as follows:
Classified by quality
Ordinary steel: (P≤0.045%, S≤0.050%);
High-quality steel: (P, S≤0.035%);
High quality steel: (P≤0.035%, S≤0.030%).
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%).
Low alloy steel (total content of alloying elements < 5%); b. Medium alloy steel (5% ≤ total content of alloying elements ≤ 10%); c. High alloy steel (total content of alloying elements > 10%).
Classified by forming method
(1) Forged steel; (2) Cast steel; (3) Hot rolled steel; (4) Cold drawn steel.
Classification by Metallographic Organization
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. bainite steel; c. martensitic steel; d. austenitic steel. (3) No phase change or partial phase change
Classification by purpose
Engineering steel: a. Ordinary carbon structural steel; b. Low alloy structural steel; c. Reinforced steel.
Carburizing steel: a. Nitriding steel; b. Steel for surface quenching; c. Easy-cut structural steel; d. Steel for cold plastic forming: including steel for cold stamping and steel for cold heading.
Carbon tool steel; a. Alloy tool steel; b. High speed tool steel.
Special performance steel: a. Stainless acid-resistant steel; b. Heat-resistant steel: including anti-oxidation steel, heat-strength steel, valve steel; c. Electric heating alloy steel; d. Wear-resistant steel; e. Steel for low temperature; f. Electrical steel.
Steel for bridges, steel for ships, steel for boilers, steel for pressure vessels, steel for agricultural machinery, etc.