Effect of titanium additions to low carbon, low manganese steels

Recent developments of high strength line pipe steel have seen a decrease in carbon content from 0.25 wt% to less than 0.05 wt% and manganese to less than 1 wt% in an attempt to reduce centreline segregation. The sulphur content should be less than 0.008 wt% as well. However, recent papers argued that low manganese levels in pipeline steels have the potential to improve weld line toughness and allow a higher tolerance for sulphur. Should this be true it would be possible to eliminate the usual desulphurising treatments decreasing the production cost. The current study was designed to explore the effect of titanium on sulphide precipitation in steels with higher sulphur contents than currently used in the pipeline industry. The mechanical properties of steels are influenced by the type, shape and size of sulphide precipitates. Titanium additions to low carbon steel influence the precipitation behavior and composition of sulphide precipitates and could provide grain refinement, precipitation strengthening and sulphide shape control.

Autorentext

Dr. Sima Aminorroaya is a research fellow in the University of Wollongong. She finished her Master's degree in 2000 in the Isfahan University of Technology then established her own company and worked in the pyrometallurgy field for 4 years. She received her PhD degree in 2009 on physical metallurgy from the University of Wollongong.