Comparative study on a 0.2C steel treated by Q&P and A&T treatments

The effect of various versions of quenching and partitioning (Q&P) and austempering plus tempering (A&T) processes on the combined properties and microstructure of a 0.2C-0.8Si-2.2Mn bainitic steel has been investigated. Results show that the steel exhibits a higher value of product of strength and elongation (PSE) than that reported before with similar compositions. The one-step Q&P process at 230°C and A&T process at 450°C can result in a toughness higher than 80 J cm −2 and a relatively high PSE (above 29.8 GPa%). The alloy design of this steel is suggested to be beneficial for industrial production because there is a big window for similar PSE. The long-partitioning time (1 h) has good effect on combined properties.