D2 steel is an air-hardening, high-carbon, high-chromium tool steel. It has high wear and abrasion-resistant properties. It is heat treatable and will offer a hardness in the range of 55-62 HRC, and is machinable in the annealed condition. D2 steel shows little distortion on correct hardening. D2 steel’s high chromium content gives it mild corrosion-resisting properties in the hardened conditions.
A high carbon high chromium tool steel grade offering very high wear resistance and toughness. D2 tool steel hardens in air with a low order of movement and offers a measure of corrosion resistance when polished. Commonly used for tools operating under conditions of severe wear and abrasion or as an alternative to oil hardening tool steel grades when long runs are required.
Typical applications for D2 Steel:
Stamping or Forming Dies
• Forming Rolls
• Knives, slitters, shear blades
• Scrap choppers
• Tyre shredders
Equivalent materials to D2 tool steels are:
• DIN 1.2379
• NI KU
• B.S. BD 2
• ASTM A681
• FED QQ-T-570
• SAE J437
• SAE J438
• UNS T30402
The following table shows the chemical composition of D2 steel:
Heat treatment temperatures, including the rate of heating, cooling, and soaking times will vary due to factors such as the shape and size of each D2 steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium, and workpiece transfer facilities.
It is preferable to heat the tools in a controlled atmosphere. If this is not possible, pack hardening is recommended. A reducing atmosphere is desirable. Preheat the D2 tool steel component to 750-800°C. and allow soaking at this temperature. The tools may then be brought up to 1000-1040°C for air cooling, or 980°C for oil quenching. Soak thoroughly at the temperature for thirty minutes per 25mm of the ruling section, then cool or quench accordingly. It is important not to exceed 1040°C when heating for hardening.