HRC58-60 Hardened Screw & Barrel – Long Life PP Band Line

The screw and barrel of the extruder are the components that withstand the most wear, and their surface hardness directly determines equipment service life. In this production line, both screw and barrel are made of 38CrMoAlA alloy steel, and after full nitriding, the surface hardness reaches HRC58-60. This hardness level is close to tool steel hardening, effectively resisting abrasion from hard particles that may exist in PP materials (such as fillers, regrind impurities). Additionally, the inner surface hardness of the barrel is R2-R3 degrees higher than the screw flight crest, forming a "hard-on-hard" but slightly mismatched fit, further reducing adhesive wear. This high-hardness combination ensures that core components maintain dimensional accuracy during long-term operation, greatly reducing maintenance frequency.

• High hardness: HRC58-60 effectively resists abrasive wear from hard particles
• Nitrided treatment: Full nitriding ensures uniform hardness with no soft spots
• Hardness gradient: Barrel inner hardness higher than screw flight reduces adhesive wear
• Wear life: Under normal PP processing, core component life 5-10 years
• Fatigue resistance: Nitrided layer improves surface contact fatigue resistance
• Corrosion resistance: Nitrided layer resists chemical attack
• Dimensional stability: High hardness keeps clearance from increasing over time
• Low maintenance: Reduces screw/barrel replacement frequency
• Cost-effective: Higher initial cost but lower total lifecycle cost
• Suitable for modified materials: Especially beneficial for glass-filled, mineral-filled PP