Development of high strength interstitial free steel by copper precipitation hardening

A novel route of strengthening mild interstitial free steels has been suggested in the current investigation based on copper precipitation hardening. A possible scheme of application of this new high strength automotive steel has also been outlined. It has been shown that with the addition of 1.18 wt.% copper, a yield strength of ∼ 456 MPa and tensile strength of ∼ 566 MPa can be achieved through a post annealing ageing treatment. The present copper-containing interstitial free steel is far stronger than the existing high strength interstitial free steels.