Common Materials For Screw Pairs

The commonly used screw materials in China include 45 steel, 40Cr, ammoniated steel, 38CrMOAl, high-temperature alloys, etc. 1) 45 steel is cheap and has good processing performance, but its wear and corrosion resistance are poor. Heat treatment: quenched and tempered HB220-270, high-frequency quenched HRC45-48. 2) The performance of 40Cr is better than that of 45 steel, but it often requires a layer of chromium plating to improve its corrosion and wear resistance. However, high requirements are placed on the chrome plating layer. If the plating layer is too thin, it is prone to wear and tear, while if it is too thick, it is prone to peeling off. After peeling off, it actually accelerates corrosion and is less commonly used. Heat treatment: quenched and tempered HB220-270, plated with hard chromium (HRC>553), nitrided steel, and 38CrMoAl have excellent comprehensive properties and are widely used. The general nitride layer reaches 0.4-0.6 millimeters. But this material has low resistance to hydrogen chloride corrosion and is relatively expensive. 4) High temperature alloy materials are superior to other materials. This material does not require coating and is mainly used for producing halogen-free screws in injection molding machines. This material has high oxidation and corrosion resistance, and heat treatment is required