Characteristics of A681 A2 Mold Steel
High Toughness and Wear Resistance
A2 steel is an air-hardening cold work mold steel renowned for its exceptional toughness and wear resistance. With a carbon content of approximately 0.95–1.05%, chromium content of about 4.75–5.50%, and added elements such as molybdenum (0.90–1.40%) and vanadium (0.15–0.50%), it forms a uniform and fine carbide distribution. This composition enables it to achieve a hardness of 57–62 HRC after heat treatment while maintaining high toughness, making it a standout representative among cold work mold steels. It effectively reduces the risk of mold cracking and chipping, extending service life.
Superior Hardenability and Dimensional Stability
A2 steel utilizes a chromium-molybdenum alloy system, and its air-quenching process ensures excellent hardenability with uniform carbide distribution. It exhibits minimal dimensional deformation and low residual stress after heat treatment, making it particularly suitable for manufacturing precision molds. For example, high-temperature tempering after wire electrical discharge machining (EDM) can eliminate over 97% of residual stress, effectively suppressing mold deformation and ensuring machining accuracy.
Excellent Machinability
Cutting and Grinding Performance: A2 steel offers 15–20% higher cutting efficiency compared to SKD11 steel and exhibits superior grindability, supporting deep processing techniques such as stamping and bending. This reduces machining costs and shortens production time.
Easy Weld Repair: The preheating and post-heating temperatures for A2 steel are 50°C lower than those for SKD11 steel, simplifying repair welding operations and reducing the risk of brittleness in the heat-affected zone.
Strong Thermal Treatment Stability
Advantages of Vacuum Heat Treatment: Surface hardness deviation after vacuum heat treatment does not exceed ±1 HRC, ensuring consistent mold performance.
Corrosion Resistance and Surface Properties
Corrosion Resistance: Although A2 steel has a darker surface luster after polishing, its corrosion resistance is superior to that of conventional cold work mold steels, delaying mold rusting and lowering maintenance costs.
Surface Hardening Treatment: After surface hardening, A2 steel achieves higher surface hardness than SKD11, further enhancing mold wear resistance and fatigue performance.
