W2 was designed for applications where a very high surface hardness and a soft core were desirable. It has a wide range of carbon contents (0.6-1.4% C) and can have very good abrasion resistance in the higher range. Although it is designated a "water" hardening steel it is only stable and safer for this hardening methods in very simple cross sections like knives, but it is capable of very high hardness in thin sections using oil. It has a small amount of vanadium (0.15-0.35%) added which helps this steel maintain a fine grain, a useful quality for forging.
Recommended Working Sequence For W2
Forging: 1800°F to 1900°F (980 to 1065°C) with the lower range better for higher carbon contents. Do not forge below 1500 °F (815 °C)
Normalizing: Heat to 1600 °F (870 °C). Cool in still air. Heat to 1500°F for the lower carbon contents.
Annealing: Heat to 1400 °F (760 °C) for higher carbon contents. Furnace cool to 1000 °F (540 °C) at a rate not exceeding 50 °F (28 °C) per hour.
Grinding or Machining
Hardening: Austenitize- Heat to 1450 °F to 1475°F (790 °C to 800°C). Using the higher temperatures will increase hardenability. In thicker sections can be quenched in water or brine with extreme care but can also be oil quenched in sections under 1/4 in. (6.35 mm) thick as the preferred method.
Tempering: As-quenched hardness of approximately 65 to 67 HRC. Hardness can be adjusted downward by proper tempering.
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