Effect of Alloy Addition on Mechanical Properties and Decarburization Sensitivity of Spring Steel

Abstract

The mechanical properties and decarburization layer depths after heat treatment have been investigated for the experimental steels，which were melted by means of 10Kg vacuum induction furnace in the laboratory . It has been confirmed that additions of silicon and vanadium can improve strength of the steels and, the tensile strength of the steels increases with silicon content from 1.4% up to 2.0%. The reduction of carbon content and the addition of carbide forming elements decrease the decarburization sensitivity of the steels tested. The tensile strengths of the steels with carbon less than 0.5% are between 1016.88 to 1674.64 MPa, and the impact energy between 15.50 to 34.50 J, which are compared with the tensile strength of 1160.89MPa, the impact energy of 19.00 J for 55SiCrV. The steels with optimized compositions, which consists of 0.4~0.5% C, 1.6~2.0% Si, 0.8% Cr, 0.2% V, have a satisfactory property with high strength, high toughness and good anti-decarburization.