Cr12

Cr12 is an alloy tool steel with good hardenability and excellent wear resistance, primarily used for cold forming dies and punches that require high wear resistance and less impact load, as well as cold cutting shears, drill bushes, gauges, wire drawing dies, embossing dies, screw rolling dies, and drawing dies.

Application Scope

It is a widely used cold working die steel with high strength, good hardenability, and good wear resistance, but poor impact toughness. Mainly used for cold forming dies and punches that require high wear resistance and withstand low impact loads, such as cold cutting shears, drill bushes, gauges, wire drawing dies, embossing dies, screw rolling dies, and stretching dies.

Cr12 die steel is a high-carbon, high-chromium ledeburite steel, widely used as cold working die steel. It boasts excellent hardenability, wear resistance, and thermal processing properties. The carbides are well-distributed within the steel, making it suitable for manufacturing complex-shaped dies under heavy working conditions, such as cold extrusion dies, thread rolling dies, wire drawing dies, material molds, metallurgical powder molds, woodworking cutting tools, cold cutting shears, drill bushes, and gauges, etc. During our development process, through repeated exploration and testing, we have formulated a reasonable smelting process and special ingot mold and forging techniques, ensuring uniform and consistent material structure. Additionally, for standard material processing, we have innovatively adopted the new double-edge chip-cutting technology, which has improved efficiency, shortened cycles, and reduced costs.
Chemical Composition

Unit: (%)

Carbon (C): 2.00-2.30

Silicon (Si): ≤0.40

Manganese Mn: ≤0.40

Sulfur (S): ≤0.030

Phosphorus (P): ≤0.030

Chromium (Cr): 11.50～13.00

Nickel (Ni): Allowable residue content ≤ 0.25

Copper (Cu): Allowable residual content ≤ 0.30

Cobalt (Co): ≤1.00
Mechanical properties

Hardness: Annealed, 269-271HB, indentation diameter 3.7-4.1mm; Quenched, ≥58HRC
Heat Treatment

Microstructure: Tempered Martensite + Undissolved Carbides + Residual Austenite.

Delivery Status: Steel is supplied in annealed condition.
Quenching Temperature

Cr12 quenched at 950～1000℃ oil quenching, second tempering at 550℃

High-temperature quenching at 1100-1150°C, low-temperature quenching at 960-1050°C, tempering at 550-650°C; the former exhibits secondary hardening, with at least two temperings, each for 2 hours. After tempering, it can be air-cooled or oil-cooled. Before high-temperature quenching, it's recommended to preheat twice, and protective measures must be taken during high-temperature heating to prevent oxidation.