Grade Introduction:

Cold-work tool steels which include D2, D3 steels are high-carbon, high-chromium steels. Apart from D3 steel all group D steels have 1% Mo and are air hardened. Type D3 steel is oil-quenched; though small sections can be gas quenched after austenitization using vacuum. As a result, tools made with type D3 steel tend to be brittle during hardening. Type D2 steel is the most commonly used steel among the group D steels. The D3 steels contain 1.5 to 2.35% of carbon and 12% of chromium.

Grade Application:

AISI D3 Cold Work Steel has high strength, good hardenability and wear resistance. D3 is suitable for applications such as complex blanking and forming tools for long runs and for hard and abrasive materials.

Typical Applications:

• Highly stressed cutting,
• Punching tools for thin sheets,
• Shear blades for cutting,
• Profile rolls,
• Drawing and deep drawing tools,
• Stone processing tools,
• Knives for paper and plastics,
• Shear knives for thin sheets,
• Deep drawing,
• Pressure pads,
• Highly wear-resistant plastic moulds.

Equivalent grades:

Chemical composition:

The following table shows the chemical composition of D3 steel:

Hardness:

Hardness in the range 58-64 HRC.

Heat treatment:

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 steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium, and workpiece transfer facilities.

Hardening:

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 component to 750-800°C. and allow soaking at this temperature. Raise to the hardening temperature of 950-980°C. Soak thoroughly at the temperature for thirty minutes per 25mm of the ruling section, then cool or quench accordingly.