(AISI A2)
| Typical Chemistry | |
| Carbon | 1.00% |
| Manganese | 0.85% |
| Silicon | 0.35% |
| Chromium | 5.25% |
| Molybdenum | 1.10% |
| Vanadium | 0.25% |
| Typical Applications | ||
| Mold Inserts | Barrel Liners | |
| Gate/Runner Inserts | ||
| Injection/Extrusion Screws | ||
| Non-return Valves and Tips | ||
| Granulator/Pelletizer Blades | ||
- Hardening
Preheat: 1100/1250F (595/675C), equalize, 1350/1450F (775/790C), equalize.
High Heat: 1750/1800F (995/895C), 30/45 minutes at temperature.
Quench: Air, positive pressure vacuum to 150F (65C).
Temper: 400/1000F (205/540C), hold 2 hours at temperature, air cool. Temper twice.
Cryogenic Treating: Refrigeration treatments may improve long term dimensional stability by transforming retained austenite. Refrigeration treatments should generally be performed after the first temper, and must be followed by a temper.
Hardness and Impact Toughness Data
Air cooled from 1775F(970C)
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Hardness |
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HRC |
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| As quenched | 64 | - | – | |
| 300 | 150 | 62 | - | – |
| 400 | 205 | 61 | 31 | (42) |
| 500 | 260 | 60 | 41 | (56) |
| 600 | 315 | 59 | 37 | (50) |
| 700 | 379 | 58 | 33 | (45) |
| 800 | 425 | 58 | 31 | (42) |
| 900 | 480 | 58 | 29 | (39) |
| 1000 | 540 | 57 | 41 | (56) |
| 1100 | 595 | 51 | - | – |
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Airkool can be given standard surface treatments such as nitriding, titanium nitride coating, or hard chrome plating if desired. When gas nitriding, harden from the high side of the temperature range and single temper at 1000F (540C); then use standard nitriding procedures.
Annealing
A. Heat to 1600F (870C), hold 2 hours, slow cool 50F (30C)/hour maximum) to 1200F (650C), air cool.
OR
B. Heat to 1600F (870C), hold 2 hours, cool to 1400F (760C), hold 6 hours, air cool.
Typical annealed hardness: 197/241 BHN.
Stress Relieving
Annealed Material: Heat to 1200/1250F(650/675C), hold two hours, cool in still air.
Hardened Material: Heat to 25F(15C) below original tempering temperature, hold two hours, cool in still air.
Welding
Use air hardening tool steel filler material.
Annealed Material: Preheat to 400/600F(205/315C). Maintain above 400F(205C) during welding. Reanneal or temper 1400F(760C) 6 hours.
Hardened Material: Preheat to 25F(15C) below original tempering temperature (300F(150C) minimum). Maintain above 300F(150C) during welding. Cool to 150F(65C) after welding. Temper 25F(15C) below original tempering temperature.
Physical Properties
Modulus of Elasticity ..............................30 psi x 106 ..................(207 GPa)
Density ......................................................0.284 lb/in3 ...............(7861 kg/M3)
Thermal Conductivity ...........................15 BTU/hr./ft./F ............(26 W/m/ °K)
Thermal Expansion
| Temperature Range |
Coefficient of Thermal Expansion | ||
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