Metallurgical Effect of Rare-Earth Lanthanum Fluoride and Boride in the Composite Coating of Wires in the Arc Welding of Bainitic-Martensitic and Austenitic Steel

Metals

SergeyG. Parshin¹ 

[1] Department of Welding and Laser Technologies, Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia;

关键词: welding metallurgy;    rare earth compounds;    microstructural refinement;   

DOI  :  10.3390/met10101334

来源: DOAJ

【 摘 要 】

For arc welding of high-strength and cold-resistant steels, the author developed an advanced design of steel wire with a micro-composite coating of a nickel matrix and nanoparticles of LaF₃ and LaB₆, which improves the metallurgical influence of rare-earth elements (REE) and forms refractory sulphides and oxides of REE, as well as boron nitride. The addition of 0.1–0.3 wt% La in the weld pool leads to an increase in the content of the refractory compounds La₂O₃, LaO₂, and LaS, and to the reduction in the content of the low-melting and brittle oxides and sulphides SiO₂, SiO, MnO, MnS, and SiS. The use of steel wire with the composite coating of LaF₃ and LaB₆ allows for microstructural refinement when welding S960QL bainitic-martensitic steel and X70 API bainitic steel, and increases the impact toughness of the welds by 1.17–1.6 times.

【 授权许可】

Unknown