Improvement of Cu-rich precipitation strengthening for high-strength low carbon steel strengthened via Ti-microalloying

•Ti microalloying increased the nucleation sites for Cu-rich particles.•The addition of Ti impeded the enrichment of Cu in Cu-rich particles.•Ti microalloying made Cu-rich particles maintain semi-coherent 3R or 9R structure in tempering process.•By adding 0.05 wt% Ti, the precipitation strengthening of Cu-rich particles increased from 46 MPa to 248 MPa.