30CrMo/30CrMoA/SCM430/ASTM A29/4130/EN 25CrMo4/1.7218

• Chemical Composition (mass fraction%)

Carbon (C): 0.26-0.34%Chromium

(Cr): 0.80-1.10%Molybdenum

(Mo): 0.15-0.25%Silicon

(Si): 0.17-0.37%Manganese

(Mn): 0.40-0.70%Phosphorus

(P) and sulfur (S): both ≤ 0.035%

• Physical and Mechanical Properties

Density: Approximately 7.85 g/cm ³.

Tensile strength: ≥ 930 MPa (quenched and tempered state).

Yield strength: ≥ 785 MPa.

Hardness (HBW): ≤ 229 (annealed state).

Thermal conductivity: approximately 53 W/(m · K) at 20 ℃.

• Main Purpose

1. Mechanical manufacturing: used for high stress components such as crankshafts, gears, and transmission shafts in automotive engines.

2. Pressure vessels and pipelines: Manufacturing high-pressure vessels, petroleum pipelines, and boiler components.

3. Fasteners: Produce high-strength bolts (such as 10.9S and 8.8S grades).

4. Engineering structure: welded structural components, main shafts and load-bearing components of engineering machinery.

5. High temperature components: Fasteners such as flanges and nuts that work in an environment of 450-500 ℃.Note: The corresponding information of Russian standards is not explicitly mentioned in the existing materials. It is recommended to further verify the relevant standard database.