What domestic grade is the American standard SAE4130 alloy steel equivalent to?
4130 alloy structural steel: Implementation standard: ASTM A29/A29M-04. This steel is usually used in the quenched and tempered state. When the carbon content is at the lower limit, the steel can also be used as carburizing steel with higher core strength. It has high strength and toughness, high hardenability, and the critical hardenability diameter in oil is 15-70mm. The steel also has good thermal strength, with sufficient high temperature strength below 500℃, but its strength drops significantly at 550℃.
Corresponding Japanese brand: SCM430 (SCM2)
Corresponding German brand: 34CrMo4 (1.7220)
Chemical composition
Carbon C: 0.28-0.33
Silicon Si: 0.15-0.35
Manganese Mn: 0.40-0.60
Sulfur S: Allowable residual content ≤0.040
Phosphorus P: Allowable residual content ≤0.035
Chromium Cr: 0.80-1.10
Nickel Ni: Allowable residual content ≤0.030
Copper Cu: Allowable residual content ≤0.030
Molybdenum Mo: 0.15～0.25
Mechanical properties
Tensile strength σb (MPa): ≥930(95)
Strength σs (MPa): ≥785(80)
Elongation δ5 (%): ≥12
Sectional reduction ψ (%): ≥50
Impact energy Akv (J): ≥63
Impact toughness value αkv (J/cm2): ≥78(8)
Hardness: ≤229HB
Specimen size: The blank size of the specimen is 25mm
Application
In the medium-sized machinery manufacturing industry, it is mainly used to manufacture quenched and tempered parts with large cross-sections and working under high stress conditions, such as shafts, spindles, and high-load control wheels, bolts, studs, gears, etc.; in the chemical industry, it is used to manufacture welded parts, welded structures composed of plates and pipes, and high-pressure pipes with a temperature not exceeding 250°C in nitrogen and hydrogen media; in the turbine and boiler manufacturing industry, it is used to manufacture fasteners working below 450°C, flanges and flange covers under high pressure below 500°C.
