Quick Details

1: D2 steel introduction

    Cold-work tool steels include the high-carbon, high-chromium steels or group D steels, D2 is the most popular one,these steels all contain 1.5% to 2.35% of carbon and 12% of chromium. 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 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 condition.

    If customer need better machinability, we recommend A2, because A2 has a chromium content of 5% and is more readily machinable.

2: D2 steel application

   D2 tool steels are used for long run tooling applications, where wear resistance is important, such as blanking or forming dies, punches, forming rolls, knives, slitters, shear blades, tools, scrap choppers, tyre shredders and so on.

3: D2 Steel equivalent

4: D2 steel chemical composition

5: D2 steel mechanical properties

    The mechanical properties mainly include tensile strength, yield strength, elongation, area or reduction, hardness, impact value, non-metalic inclusion etc. Different heat treatment, the mechanical properties will be different, such as normalized, tempered, QT. If you want to know the properties, kindly contact the salesman.

6: ASTM D2 steel overviews

7: D2 steel heating treatment

    ASTM D2 steels alloy should be preheated very slowly to 815℃ (1500°F) and then temperature can be increased to 1010oC (1850°F). They are then held at 1010oC (1850°F) for 20 to 45 minutes and air cooled (air quenched).

Annealing

    Annealing of D2 tool steels material should be done at 871 to 898°C (1600 to 1650°F) followed by slow furnace cooling at 4.4°C (40°F) per hour or less.after which cooling rate may be increased. Suitable precautions must be taken to prevent excessive carburization or decarburization.

Stress Relieving

    When desirable to relieve the strains of machining, heat D2 grade steel slowly to 1050°-1250°F, allow to equalize, and then cool in still air (Strain Relieving).

    Preheat Prior To Hardening

    Preheat slowly to 1350°-1450°F and hold at this temperature until grade steel D2 material is uniformly heated.

Hardening

    After thorough preheating, heat to 1800°-1850°F. Hold the work piece at the hardening temperature until it is completely and uniformly heated.

Quenching

    AISI D2 steel tool material is an air hardening steel and will develop hardness on cooling in still air. To avoid scaling and prevent decarburization of the work piece surface, controlled atmosphere or vacuum furnaces are recommended. If these furnaces are not available, pack hardening, salt baths or wrapping the piece in stainless steel foil will provide some degree of surface protection in the hardening process. Parts should be allowed to cool to 150F, or to where they can be held in the bare hand, and then temper immediately.

Tempering

    The tempering temperature on material D2 steel may be varied according to the desired hardness. D2 steels can be tempered at 204°C (400°F) for achieving Rockwell C hardness of 61 and at 537°C (1000°F) for a Rockwell C hardness of 54.

8: Delivery condition

    For hot forged or hot rolled bar, usually the delivery condition is hot forged or rolled, annealed, rough turned.

    For hot forged plate, usually the delivery condition is hot forged, annealed, milled surface.

    For hot rolled plate, usually the delivery condition is hot rolled, annealed, black surface.