Addition of nanoparticles to flux cored wires for the nucleation of acicular ferrite micro-structure in weld metals of the high-strength low-alloy steel

摘要

For the reliability of many welded structures like pipelines or offshore wind parks, it is necessary to ensure high mechanical properties such as strength and toughness of the entire material. In order to improve quality of weld joints, flux cored rods and wires containing different nanoparticles (ZrO_2, LaB_6 and Al_2O_3) were manufactured and welded with the TIG and MAG welding processes. Influence of these nanoparticles on the microstructure and mechanical properties of the weld joints were investigated. The acicular ferrite and improved strength of the weld metals were observed by the addition of 0.2 wt.% of iron powder with ZrO_2 nanoparticles to the filling of flux cored wires.