It is shown that the barium–strontium carbonatite can be used as a refining and gas-shielding addition for welding fluxes.Welding with the barium–strontium carbonatite reduces the degree of contamination of the welded joint with non-metallic inclusions: non-deformed silicates, spot oxides in brittle silicates, and also increases the desulfurization capacity of the welding fluxes. The addition of the barium–strontium carbonatite to the flux based on the slag of silicomanganese in the amount of up to 5% results in the formation of a ferritic–pearlitic structure of the metal of the welded joint with the Widmanstätten direction, with a small decrease of the grain size. The impact toughness and yield strength of the specimens increase as a result of adding the barium–strontium carbonatite to the flux, and the ductility properties and ultimate tensile strength of the samples decrease.

The technologies for manufacturing of welding fluxes with the use of slag from silicomanganese production and dust of gas purification from aluminum production are developed. The new compositions and production technology of welding fluxes are offered. The comparative evaluation of the new compositions and widely used AN-348 flux is provided. It is shown that the quality of submerged arc welding with the use of the developed flux composition is significantly better than the submerged arc welding with AN-348 flux. The effect of fractional composition on high-quality performance of the weld is investigated. The macro-and microstructures, nonmetallic inclusions and the mechanical properties of the weld are examined. It is shown that the introduction of carbon-fluorine containing additive into the flux, based on the dust of gas purification from aluminum production, can significantly improve the whole complex of mechanical properties of the weld, especially characteristics of impact hardness at low temperatures. The conducted research served as a basis for development of submerged arc welding technologies protected by the patents of the Russian Federation.

The possibility in principle of using slag, which is formed in the silicon-manganese smelting process, in producing welding fluxes is shown. The composition of and technology used for a new fused flux has been designed. A comparative evaluation of the new flux and the widely used AN-348 type flux was done. It has been proved that the new flux has high strength properties.

Experimental study of the effect of the introduction of carbonfl uorine additives containing 14,01 – 22,72 % Al; 13 – 22,04 % F; 13,16 – 21,34 % C; 8,27 – 13,4 % Na; 0,09 – 0,14 % K; 0,66 – 1,09 % Ca; 26,11 – 42,35 % SiO2 ; 1,15 – 1,86 % FeO; 0,07 – 0,12 % MnO; 0,001 – 0,1 % MgO; 1,47 – 2,38 % S; 0,03 – 0,05 % P into oxidative fl uxes AN-348, AN-60, AN-67 when welding of steel 09G2S and aluminate-base OK Flux 10.71 fl ux at welding of steel 10HSND has been carried out. In the experiments it has been shown that from the point of view of the exclusion of formation in the weld of non-metallic inclusions, it is optimal to use carbon as a deoxidizer, as formed with the participation of gaseous carbon compounds (CO and CO2 ) are easily removed and do not contaminate the weld metal with non-metallic inclusions. The studies have shown that the carbon-fl uorine-containing additive in the composition of the fl uxes has a positive effect on the quality of the weld. It has been found out that when using the analyzed additives in the amount of 4 - 6% in the data fl uxes the overall oxygen content in the weld reduces. Fractional gas analysis revealed that the largest number of aluminates and silicates adversely affect the physico- chemical properties of welded joints, contained in the submergedarc welding of AN-60 and OK Flux 10.71, with the introduction of additives the reduction of these compounds has been observed, while in AN-348 and AN-67 fl uxes changes have been insignifi cant. When using the proposed additives the required mechanical properties, as well as impact strength at low temperatures by reducing contamination of the weld with oxide non-metallic inclusions increase, and the concentration of carbon in the weld remains at the level of the base metal.

The influence of a carbon-fluorine additive in AN-348, AN-60, and AN-67 oxidative flux on the welding of 09Γ2C steel and in OK Flux 10.71 basic aluminate flux on the welding of 10XCHД steel is studied experimentally. The composition of the additive is as follows: 14.01–22.72% Al, 13–22.04% F, 13.16–21.34% C, 8.27–13.4% Na, 0.09–0.14% K, 0.66–1.09% Ca, 26.11–42.35% SiO2, 1.15–1.86% FeO, 0.07–0.12% MnO, 0.001–0.1% MgO, 1.47–2.38% S, and 0.03–0.05% P. The experiments show that the use of carbon as the reducing agent is optimal in terms of preventing the formation of nonmetallic inclusions in the weld seam, since its gaseous compounds CO and CO2 are easily captured and do not introduce nonmetallic inclusions in the weld seam. With 4–6% carbon-fluorine additive in the fluxes, the total oxygen content in the seam falls. When using the proposed additive, the mechanical properties and the impact strength at negative temperatures are improved on account of the lower content of nonmetallic inclusions (oxides) in the weld seam. The carbon concentration in the weld seam remains the same as in the basic steel.