Microstructure and Mechanical Properties of High Toughness, Control Rolled Copper-Niobium Steels with Zero Nickel Content

摘要

An investigation into controlled rolled, low carbon Cu-Nb steels is described. Age hardening curves and mechanical properties were determined on the steels. Although addition of 1.5%Cr leads to an increase in tensile strength, such steels are hot short. However, a steel consisting of 0.049%C, 1.27%Mn, 0.78%Cu and 0.03%Nb (wt.%), without Ni, controlled rolled satisfactorily, with only slight edge cracking. In aged condition, this steel had a DBTT of -95±10℃ and impact energy of 184 J at -42℃, a 0.2% proof stress of 522 MPa and a tensile strength of 620 MPa. It is thought that such steel would find application as automobile chassis members of reduced weight, specialised military vehicles and in the oil/gas industry for pressure vessels and pipelines.