Standard: GB / T 1222-1984
● Features and application:
65Mn spring steel, manganese improve hardenability, φ12mm the hardenability of steel oil can, a small surface decarburization tendency than silicon, the mechanical properties after heat treatment is better than carbon steel, but overheating sensitivity and temper brittleness. As small size of flat, round spring, spring seat, spring winding, spring ring can also be produced, valve springs, clutch springs, brake springs and cold drawn steel wire cold roll coil spring.
65mn strength hardness and elasticity hardenability steel is higher than 65, with a thermal sensitivity and tendency to temper brittleness, water quenching have to cracking tendencies. Cutting can still be annealed, cold plastic deformation is low, poor welding. By the middle of the plate spring load, diameter 7-20mm of coil spring and spring washer. Spring ring. High wear parts, such as grinding spindle of spring chuck. Precision machine screw. Cutter, spiral roller bearings on the rings. Railroad rails, etc.
Chemical composition
● Chemical Composition:
Carbon C: 0.62 ~ 0.70 Si Si: 0.17 ~ 0.37
Manganese Mn: 0.90 ~ 1.20
Sulfur S: ≤ 0.035
Phosphorus P: ≤ 0.035
Chromium Cr: ≤ 0.25
Ni-Ni: ≤ 0.30
Copper Cu: ≤ 0.25
Mechanical properties
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 980 (100)
Yield strength σs (MPa): ≥ 784 (80)
Elongation δ10 (%): ≥ 8
Reduction of area ψ (%): ≥ 30
Hardness: hot, ≤ 302HB; cold-drawn + heat treatment, ≤ 321HB
Heat treatment specifications
● Heat treatment and microstructure specifications:
Standard heat treatment: quenching 830 ℃ ± 20 ℃, oil cooling; tempering 540 ℃ ± 50 ℃ (special needs, ± 30 ℃).
Microstructure: troostite.
● Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold-drawn steel with heat treatment delivery.
● supply specifications:
Coiled: Φ5.5 ~ 16mm
Roll: Φ120 ~ 150mm
Forging: Φ160 ~ 450mm
65Mn density
65Mn density ρ = 7.81 g / cc, the steel can be cold rolled into plate, strip and wire, making the spring. 65Mn can be made into such fitter's chisel, stylus and other tools. 65Mn steel section can be made generally about 8 ~ 15mm size of a small spring, such as various small flat, round springs, bottom spring pads, spring winding.
