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Pre hardened supply: No heat treatment required, direct processing, short cycle, low cost.
Dense organization: Forging+vacuum degassing, high purity, polishing up to Ra ≤ 0.2 μ m (mirror surface), uniform etching pattern.
Good cutting performance: uniform hardness, low sulfur content, low tool wear, suitable for large/complex cavity machining.
Excellent toughness: tensile strength of 850-1000MPa, deformation resistance and wear resistance, with a lifespan of about 500000 molds.
Dimensional stability: Low internal stress, not easily deformed/cracked during long-term production.
GB | JIS | ASTM | ASSAB | DIN | W-Nr. | AFNOR | SS |
3Cr2Mo | SCM4/SCrM3 | P20 | 618 | 40CrMnMo7 | 1.2311 | 40CMD8 | 2242 |
element | C | Si | Mn | Cr | Mo | S | P |
scope | 0.28–0.40 | 0.20–0.80 | 0.60–1.00 | 1.40–2.00 | 0.30–0.55 | ≤0.03 | ≤0.03 |
Tensile strength Rm (MPa) | Yield strength ReL (MPa) | Elongation A (%) | Reduction of area Z (%) | Impact toughness Akv (V-type J/cm² ) | hardness ( HRC ) |
965-1030 | 827-862 | ≥ 20 | 40-50 | 27-34 | 28-34 |
Heating: 1180-1220 ℃, uniform insulation, anti overheating/overburning.
Initial forging: 1120-1180 ℃; Final forging: ≥ 850 ℃, to avoid low-temperature brittleness.
Forging method: using upsetting and elongation to repeatedly forge, breaking the as cast structure, eliminating segregation, and ensuring that the fiber streamline is consistent with the direction of force on the mold cavity.
Cooling after forging: slow cooling (sand cooling/furnace cooling) to prevent cracking; Subsequent pre hardening treatment (oil quenching at 820-860 ℃+tempering at 550-650 ℃) was carried out to stabilize the hardness to HRC30-36.
Ultrasonic testing: 100% ultrasonic testing, no defects such as pores, shrinkage, cracks, etc.
Home appliances: TV case, washing machine/refrigerator liner, water dispenser, vacuum cleaner shell.
Cars: dashboard, interior parts, headlight covers, bumper molds.
Daily necessities: buckets, storage boxes, transparent containers, packaging product molds.
Mold frame: Large and medium-sized standard mold frame, cushion block, support plate.
