At present, the commonly used materials in China are 45, 40Cr and 38CrMoAIA. Alloy steel 34CrAINi and CrMoV9 are commonly used in the manufacturing material of the cylinder in the imported injection molding machine. The yield strength of this material is about 900MPa. After nitriding treatment, the hardness is above 1000HV, which is wear-resistant and has good corrosion resistance. Tungsten carbide alloy barrel, tungsten carbide alloy + chromium alloy barrel, tungsten carbide alloy + chromium alloy alloy barrel, Material quality alloy steel is selected as the base Material, and inner hole is cast to cast the above alloy to improve the wear and corrosion resistance of the barrel.