What is the bimetallic barrel, the main ingredient is what?

Bimetallic barrel (bimetallic), the barrel base alloy structure steel, the hole centrifugal casting 2-3mm thick alloy layer. Jinyang double alloy barrel alloy composition of tungsten carbide alloy, nickel-based alloy, cobalt-based alloy, with wear-resistant, corrosion-resistant, high temperature, high-speed high-pressure-resistant performance. POM, PBT, PEEK, halogen-free materials, magnetic powder and other special, high temperature, high corrosive plastic; and PC, PMMA transparent material.