Studies of the Influence of D -Transition Rare Earth Metals on Steel Resistance

In aggressive environments under a load, steels are subject to chloride corrosion cracking as cracks on the metal surface. This work proposes compositions of steel with additives from groups 5–8, d-transition rare earth metals (REMs) Ni, V, W, and Re, intended to function under constant tensile stresses in an aggressive corrosive environment. Technologies have been developed for the mass industrial production of steel in an electric arc furnace (EAF) with the batch introduction of Ni, V, W, and Re and electromagnetic mixing. For smaller volumes of serial production, electron beam remelting (EBR) with thermal and radiation-chemical effects is used. Studies have shown that the composition of alloying elements in steel during melting in an EAF and electroarc doping is identical and corresponds to that stated; with EBR, the O, P, S, Si, Al, and Ti contents decreased. In the EAF, the use of an ultrahigh purity stainless steel alloy source material does not mix impurity elements P, S, Sn, and Pb with the melt. The mass of losses of alloying elements from the total losses in the EAF is not more than 0.1%–0.15%. Re alloying leads to a stable increase in the conditional yield strength σ_0.2 and the tensile strength σ_v from 20°C to 1200°C, and the strain-to-fracture increased to 62%. Tests for the resistance of steel with additives of d-transition refractory REMs Ni, V, W, and Re against chloride corrosion cracking under the influence of tensile stresses showed that the time to fracture increased by 30%–40%.