50 # Carbon Structural Steel
Detailed introduction:
(1) High strength carbon structural steel with moderate machinability, low cold deformation plasticity, and weldability
Poor, no temper brittleness during heat treatment, but low hardenability, critical diameter in water is 13 * 30mm, and water quenching
Has a tendency to crack. This steel is usually used after heat treatment such as normalizing or quenching tempering, or high-frequency surface quenching.
(2) Supply status and hardness: Untreated state, hardness ≤ 241HBW; Annealed state, hardness ≤ 207HBS.
(3) Chemical composition (mass fraction,%)
Carbon C 0.47-0.55
Silicon Si 0.17-0.37
Manganese Mn 0.50~0.80
Phosphorus P ≤ 0.035
Sulfur S ≤ 0.035
Nickel Ni ≤ 0.30
Chromium Cr ≤ 0.15
Copper Cu ≤ 0.25
(4) Refer to the corresponding steel grade German DIN standard material number 1.1213, German DIN standard steel grade Cf53, and Chinese GB standards
The steel grade is 50, British BS standard steel grade 060A52, French AFNOR standard steel grade XC48TS, French NF standard steel grade
C50, Italy UNI standard steel grade C53, Belgium NBN standard steel grade C53, Sweden SS standard steel grade 1674, United States
AISI/SAE/ASTM standard steel grade 1050, Japanese JIS standard steel grade S50C/S53C, International Organization for Standardization ISO standard
Steel grade C50E4.
(5) Critical point temperatures (approximate values) Ac1=725 ℃, Ac3=760 ℃, Ar3=721 ℃, Ar1=690 ℃
(6) Normalization specification temperature 830 ℃± 10 ℃, air cooling (7), ordinary quenching, tempering specification quenching temperature
830 ℃± 10 ℃, cooled by water and oil; Tempering temperature 600 ℃± 10 ℃, cooled with water and oil.
(8) Suitable for manufacturing mechanical parts with dynamic loads, low impact loads, and good wear resistance requirements, such as forged gears
Friction discs, machine tool spindles, engine spindles, rollers, tie rods, spring washers, etc.