Chemical composition and mechanical properties of 35SiMn alloy structural steel

35SiMn is an alloy structural steel, with a unified numerical code of A10352 and an execution standard of GB/T 3077. It is a type of alloy quenched and tempered steel with good performance and relatively economy.

Chemical composition of 35SiMn alloy structural steel:
Carbon C: 0.32-0.40
Silicon Si: 1.10-1.40
Manganese Mn: 1.10-1.40
Sulfur S ≤ 0.35
Phosphorus P ≤ 0.35
Chromium Cr ≤ 0.30
Nickel Ni ≤ 0.30
Copper Cu ≤ 0.30

Mechanical properties of 35SiMn alloy structural steel:
Tensile strength σb (MPa)≥885 (90)
yield strength σs (MPa)≥735 (75)
Elongation rate δ5 (%)≥15
Reduction of area ψ (%)≥45
Impact energy Akv (J) ≥ 47
Brinell hardness 229

Delivery status of 35SiMn alloy structural steel: delivered in heat treated (normalized, annealed, or high-temperature tempered) or non heat treated state, and the delivery status should be specified in the contract.

Compared with 40Cr steel, 35SiMn alloy structural steel has similar properties to quenched and tempered parts with a cross-section below 60mm, except for slightly lower impact values at low temperatures (below -20℃). Common heat treatment methods: quenching at 900 degrees, water cooling, tempering at 570 degrees, water cooling or oil cooling. After heat treatment, the tensile strength is ≥885MPa, and the yield strength is ≥735MPa.