The development of Ti-alloyed high strength microalloy steel

Microalloy steels are generally Nb, V, or Nb, V, Ti composite microalloyed. Because of the high price of niobium and vanadium, the development of titanium microalloyed steels is a very interesting subject. In this study, steels with different Ti contents were refined and forged. Tensile tests were conducted and microstructures of samples were analyzed. Fine precipitates were observed using a transmission electron microscope. The results show that nanoscale Ti precipitates is the main factor enhancing strength of steels. The strength of steels increases with the Ti content. The optimum content range of titanium is between 0.04 and 0.10 wt.% while below 0.04 wt.% and higher than 0.10 wt.%, Ti has little effect on the strength of steels.