30CrMnSiA

30CrMnSiA is a medium-carbon steel with high strength and poor weldability. After quenching and tempering, it boasts excellent strength and sufficient toughness, as well as good hardenability. Suitable for making sandwheel shafts, gears, and sprockets. 30CrMnSiA features good machinability with minimal deformation during processing and excellent fatigue resistance. It is used for shafts, piston components, and various other automotive and aircraft special wear-resistant parts.
Brand: 30CrMnSiA Standard: GB/T 3077-1988
Carbon (C): 0.28～0.34
Silicon (Si): 0.90～1.2030% CrMnSiA round steel
Manganese (Mn): 0.80～1.10
Sulfur S: Allowable residue content ≤ 0.025
Phosphorus (P): Allowable residual content ≤ 0.025%
Chromium (Cr): 0.80～1.10
Nickel (Ni): Allowable residual content ≤ 0.030
Copper (Cu): Allowable residual content ≤ 0.025
Mechanical Properties
Tensile Strength σb (MPa): ≥1080 (110)
Yield Strength σs (MPa): ≥ 835 (85)
Tensile elongation δ5 (%): ≥10.30 CrMnSiA alloy structural round steel
Section reduction rate ψ (%): ≥45
Impact Energy Akv (J): ≥39
Impact toughness value αkv (J/cm²): ≥49 (5)
Hardness: ≤229HB
Sample Size: Sample blank size is 25mm
● Heat treatment specifications and microstructure
Heat Treatment Specifications: Quenching at 880°C, oil-cooled; Tempering at 540°C, water-cooled and oil-cooled.
Delivery Status
Shipped either in heat-treated (normalizing, annealing, or high-temperature quenching) or non-heat treated condition; the delivery state should be specified in the contract.
It has high strength but is a medium carbon quenched and tempered steel with poor hardenability, thus exhibiting poor welding properties.
The material, after heat treatment, boasts high strength and sufficient toughness, with good hardenability. It can be used to manufacture abrasive wheel shafts, gears, and sprockets after heat treatment. If used for cutting tools, it can be rough machined into the tool shape. Heat treatment is applied. The cutting edge is milled with a hard alloy milling cutter and polished to a surface roughness of 3.2, which should be no issue. The material has a rather dull color, and galvanizing isn't just for aesthetics; it also prevents rust.