Effect of Rare-Earth Elements on the Corrosion Resistance of Flux-Cored Arc-Welded Metal with 10CrNi3MoV Steel

Abstract

We modified the content of rare-earth elements (REE) in the flux-cored wire used to produce welds of high-strength low-alloy (HSLA) steel. The effect of REE addition on the microstructure as well as on the mechanical and electrochemical properties of the welded metal (WM) was investigated. REE-modified welded metals show very different responses during electrochemical impedance spectroscopy and the potentiodynamic polarization tests. The results indicate that the addition of REE of 0.3 wt.% facilitates a more uniform microstructure and improves both mechanical properties and corrosion resistance in welded metals.

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

“…3FeS + 2Ce = Ce 2 S 3 + 3Fe (6) 3FeS Thermodynamic modelling of the equilibrium phase composition of the weld pool, in accordance with the maximal solubility of the impurity substances S, O, and N in the program "Terra", confirms that the addition of 0.1-0.3% La and 0.01-0.03 B leads to the formation of refractory REE sulphides and oxides, which are I type modifiers of the microstructure [3,23], as shown in Thermodynamic modelling of the equilibrium phase composition of the weld pool, in accordance with the maximal solubility of the impurity substances S, O, and N in the program "Terra", confirms that the addition of 0.1-0.3% La and 0.01-0.03 B leads to the formation of refractory REE sulphides and oxides, which are I type modifiers of the microstructure [3,23], as shown in Figures Thermodynamic modelling of the equilibrium phase composition of the weld pool, in accordance with the maximal solubility of the impurity substances S, O, and N in the program "Terra", confirms that the addition of 0.1-0.3% La and 0.01-0.03 B leads to the formation of refractory REE sulphides and oxides, which are I type modifiers of the microstructure [3,23], as shown in…”

“…REEs reduce sensitivity to HAC and increase the impact toughness of the weld metal due to microstructural refinement, the formation of acicular ferrite, and a high affinity for sulphur and oxygen [4][5][6]. Wang et al [6] performed arc welding of HSLA steel 10CrNi3MoV, with a 14 mm thickness, using flux-cored wire with a 0.3-1 wt% rare-earth concentrate of the total flux weight in the wire.…”

“…REEs reduce sensitivity to HAC and increase the impact toughness of the weld metal due to microstructural refinement, the formation of acicular ferrite, and a high affinity for sulphur and oxygen [4][5][6]. Wang et al [6] performed arc welding of HSLA steel 10CrNi3MoV, with a 14 mm thickness, using flux-cored wire with a 0.3-1 wt% rare-earth concentrate of the total flux weight in the wire. When the content of the REE-alloy was 0.3 wt%, the tensile strength of the welds increased from 680 to 750 MPa, and the impact energy increased from 25 to 36 J at −40 • C. Similar positive results were achieved by researchers in welding and casting [7].…”