Cr12MoV Cold Work Die Steel – Material Specifications & Applications
Cr12MoV is a high-carbon, high-chromium cold work die steel defined under the Chinese standard GB/T 1299, with equivalent grades including German 1.2601 and Japanese JIS SKD-11. As a classic and widely used material, it dominates the cold working mold industry for its balanced performance in wear resistance, hardness, and dimensional stability.
I. Chemical Composition
Cr12MoV is a high-carbon, high-chromium ledeburitic alloy tool steel with the following typical chemical composition (mass fraction):
Carbon (C): 1.45% – 1.70%
Silicon (Si): ≤ 0.40%
Manganese (Mn): ≤ 0.40%
Phosphorus (P): ≤ 0.030%
Sulfur (S): ≤ 0.030%
Chromium (Cr): 11.00% – 12.50%
Molybdenum (Mo): 0.40% – 0.60%
Vanadium (V): 0.15% – 0.30%
Residual Nickel (Ni): ≤ 0.25%
Residual Copper (Cu): ≤ 0.30%
II. Key Material Characteristics
High Wear Resistance
Cr12MoV offers 3–4 times higher wear resistance than ordinary low-alloy tool steels. Its carbide hardness reaches 2000–2200 HV, supporting cold stamping die service life from 100,000 up to 1,000,000 strokes.
Excellent Hardenability
Sections under 400 mm can be fully hardened with very small quenching deformation. Workpieces ≤ 200 mm thick achieve full hardening via air cooling, with a hardness difference between surface and core of ≤ 2 HRC.
High Strength & Toughness
Tensile strength ≥ 1900 MPa, yield strength ≥ 1600 MPa, enabling resistance to heavy impact loads. Proper forging refines carbides and significantly improves transverse mechanical properties.
Good Thermal Stability
Softening resistance temperature reaches approximately 520°C. The steel maintains stable hardness and wear resistance under service temperatures of 300–400°C.
Outstanding Dimensional Stability
Retained austenite content after heat treatment is ≤ 5%, with a linear expansion coefficient of 10.5×10⁻⁶/℃ (20–500℃). Minimal dimensional change makes it ideal for precision mold making.
III. Heat Treatment Processes
Annealing
Heating temperature: 860–900℃, holding for 2–4 hours.
Cooling: 20–30℃/h to below 500℃, then 10–20℃/h to room temperature.
Purpose: Relieve internal stress, improve machinability, plasticity, and toughness.
Quenching
Heating temperature: 980–1050℃, holding for 15–30 minutes.
Cooling method: Oil quenching or gas quenching.
Hardness after quenching: Typically above 58 HRC, maximizing hardness and wear resistance.
Tempering
Temperature range: 150–550℃, selected based on required hardness and toughness.
Holding time: ≥ 2 hours, often with multiple tempering cycles.
Purpose: Eliminate quenching stress, enhance toughness, and prevent cracking during service.
IV. Typical Application Areas
Cold Working Dies
Widely used for cold blanking dies, cold bending dies, cold drawing dies, cold extrusion dies, wire drawing dies, and powder metallurgy compaction dies.
Cutting Tools & Wear Parts
Applied for taps, dies, broaches, and other high-speed cutting tools, as well as wear-resistant bushings, precision gauges, cold rolling rolls, and crusher hammers.
General Machinery Components
Suitable for high-load, high-wear mechanical parts including gears, cams, and transmission shafts.