ExEll™ P20M-High Hard
Download ExEll™ P20M-High Hard Spec sheetP20M High Hard is a higher hardness version (BHN 311-352) of this alloy. The higher hardness level offers greater mold tool wear resistance to abrasive plastic compounds as well as better surface polishing capability.
CHEMISTRY
| Typical | C | Mn | Si | Cr | Mo |
|---|---|---|---|---|---|
| Analysis % | .34 | .80 | .40 | 1.75 | .40 |
DESCRIPTION
- P-20 High Hard is a pre-hardened mold steel that has been specially designed for large plastic molds.
- Material is forged on a 5000 ton press assuring maximum deformation during the forging process.
- Supplied hardness of 321—352 HB (34-38 HRC).
- Hardness loss in large cross sections is minimal.
CHARACTERISTICS
- Improved polishability compared to P-20 modified
- Excellent compressive strength
- Minimal hardness loss in large cross sections
APPLICATIONS
- Injection molds
- Compression molds
- Mold frames
- Forming tools
- Die holders
PHYSICAL PROPERTIES
Density: 0.284 lbs/in3 (room temperature)
| Coefficient of Thermal Expansion |  |
 |
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| Thermal Conductivity |  |
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MECHANICAL PROPERTIES
Room Temperature, hardened and tempered to 321 BHN (34 HRC)
| Yield Strength | Tensile Strength | Elongation | Reduction Area |
| 130 KSI | 150 KSI | 15% | 35% |
POLISHING
P-20 High Hard can yield an A-2 surface finish when proper polishing procedures are followed. Caution must be taken to avoid over polishing which lead to orange peel effect and pitting.
HEAT TREATMENT
Stress Relieving
| Temperature | Cooling | Note |
|---|---|---|
| 850°F-900°F Hold 1 hour/inch |
Air Cool | Large cross sections require accurate control of temperatures and times. |
Tempering
- Heat uniformly and thoroughly at the selected temperature and hold at temperature for one hour per inch of total thickness.
| Temperature °F | 700 | 800 | 900 | 1000 | 1050 | 1100 | 1150 |
| Hardness HRC | 51 | 50 | 47 | 43 | 40 | 35 | 33 |
- Tempering harness is approximate and based on two hours at temperature
WELDING
- Preheat insert to 600°F to 700°F. Maintain temperature above 600°F during welding.
- Use TIG with D.C. positive polarity.
- Depending on the application, various welding rods can be used. P-20 filler which will match the hardness of the base metal after welding and tempering is commonly used. Please contact our heat treatment facility for recommendations.
- Slowly cool sown to 100°F—150°F, preferably under an insulating blanket, before post heat.
- Post heat at 1000°F one hour per inch of weld depth plus one additional hour—double temper if possible. Exceeding 1050°F could result in the loss of hardness.
| Electrode Dia. (mm) | Filler Rod Dia. (mm) | Welding AMPS | Argon Flow Lt/min | Nozzle Dia. (mm) |
| 1.0 | 1.0 | 15-80 | 4-8 | 8 |
| 1.6 | 1.6 | 70-150 | 6-9 | 8-10 |
| 2.4 | 2.4 | 100-250 | 7-10 | 8-10 |
| 3.2 | 3.2 | 250-400 | 10-15 | 8-10 |
GENERAL NOTE
All statements regarding the properties or utilization of the materials or products mentioned are for the purposes of description only. Guarantees regarding the existence of certain properties or a certain utilization are only valid if agreed upon in writing.