From the extrusion process, it can be seen that the screw works under high temperature, certain corrosion, strong wear and high torque. Therefore, the screw must:
1) be resistant to high temperature and not deform at high temperature; 2) be wear-resistant and have a long service life; 3) be resistant to corrosion, as the material is corrosive; 4) be high-strength and can withstand high torque and high speed; 5) have good cutting performance; 6) have small residual stress and small thermal deformation after heat treatment, etc.
