25th Steel is a carbon structural steel with good strength, hardness, plasticity, and toughness.

Features;

High weldability and cold work plasticity, moderate machinability, poor hardenability and quenching. Good toughness after tempering at low temperature. No tendency to temper brittleness.

Application Scope

Generally used for the production of light load cold stampings, small forgings, and machined parts such as washers, shaft pins, bolts, nuts, etc., in the manufacturing of heavy and medium-sized machinery; after carburizing or carbonitriding treatment, they can be used to produce friction plates, piston pins, and non-critical gears; after normalizing, they can be used as steel forgings for pressure vessels from -20 to 475°C. Weldments, hot forgings, and hot stampings carburized for use as wear-resistant parts.

Chemical Composition

Carbon C: 0.22~0.29

Silicon (Si): 0.17~0.37

Manganese (Mn): 0.50~0.80

Sulfur (S): ≤0.035

Phosphorus P: ≤0.035

Chromium (Cr): ≤0.25

Nickel (Ni): ≤0.30

Copper (Cu): ≤0.25

Mechanical properties;

Tensile Strength σb (MPa): ≥450 (46)

Yield Strength σs (MPa): ≥275 (28)

Tensile elongation δ5 (%): ≥23

Section reduction rate ψ (%): ≥50

Impact Energy Akv (J): ≥ 71

Impact toughness value αkv (J/cm²): ≥88 (9)

Hardness: Untreated ≤ 170 HB

Sample Size: 25mm

Heat treatment

Heat Treatment Specifications: Normalizing, 870~890℃; Quenching, 870℃; Tempering, 600℃.

Shipment Status

● Delivery Condition: Shipped in a non-heat treated or heat treated (annealing, normalizing, or high-temperature tempering) state. Delivery in a heat treated state is required to be specified in the contract; failure to specify will result in delivery without heat treatment.