Influence of Cr content and Q-P-T process on the microstructure and properties of cold-coiled spring steel

The influence of Cr content on the microstructure and properties of spring steel 60Si2CrVA (treated with quenching-tempering and quenching-partitioning-tempering (QPT) processes) was studied. Heat treatment parameters were optimized, and the appropriate Cr content was determined. Optimal microstructure and mechanical properties of 60Si2CrVA steel were obtained at 1.45 wt% Cr or 1.55 wt% Cr. Q-P-T treatment with its strength-toughness combinations is beneficial for 60Si2CrVA spring steel.