1. The twisted extruder screw should be considered according to the actual inner diameter of the barrel, and the outer diameter deviation of the new extruder screw should be manufactured according to the normal clearance with the barrel.
2. After the thread surface of the screw diameter of the wear extruder is reduced, the wear-resistant alloy is thermally sprayed, and then ground to size. This method is generally processed and repaired by a professional spraying factory, and the cost is relatively low.
3. The wear-resistant alloy is surfacing welded on the screw part of the worn extruder screw. According to the degree of wear of the extruder screw, surfacing welding is 1 to 2 mm thick, and then the extruder screw is ground to size. This wear-resistant alloy is composed of C, Cr, Vi, Co, W, and B materials, which increases the wear and corrosion resistance of the extruder screw. Professional overlay welding plants have a high cost for this type of processing, except for extruder screws with special requirements, which are rarely used.
4. The surface of the extruder screw can also be plated with hard chromium. Chrome is also a wear-resistant and corrosion-resistant metal, but the hard chromium layer is more likely to fall off.
Materials for manufacturing extruder screws and barrels
Extruder screws and barrels are manufactured. At present, commonly used materials in China are 45, 40Cr and 38CrMoAlA.
The materials used in the manufacture of extruder screws and barrels in imported extruders are 34CrAINi7 and CrMoV9. The yield strength of this material is about 900 MPa. After nitriding, the hardness is above 1000HV, which is both wear-resistant and has good corrosion resistance.