Effect of Zr-Ti combined deoxidation on the microstructure and mechanical properties of high-strength low-alloy steels

Effect of Zr-Ti combined deoxidation on the microstructures and mechanical properties of high-strength low-alloy steels were investigated by means of microstructure analysis, tensile- and Charpy impact-tests. Experimental results showed the addition of Zr-Ti based deoxidizing agent resulted in the formation of fine Zr-Ti complex oxides. Owing to abundant finely oxides dispersed in the matrix uniformly, the microstructures deoxidized using Zr-Ti was uniform and the strength was enhanced comparing against the steels deoxidized using Al based deoxidizer. The ductility and toughness of the thick steel plates deoxidized using Zr-Ti were also considerably improved, apparently due to the spheroidization and uniform dispersion of MnS.