OBRABOTKAMETALLOV technology Vol. 25 No. 4 2023 Electric furnace steel slag waste may be utilized by the cement sector [3–10]. The overseas advanced iron and steel industry recycles all blast furnace slag and a large portion of steel slag [11, 12]. The shortage of metal scrap at EAF mills triggers a quest for its replacement options: use of iron ore pellets, recycling of production waste (steel slag with 60 % of iron oxide max.), etc. [13]. A mixture of oxides is a secondary product of reducing slag into iron, and it may be used as a flux compound for submerged arc welding/weld overlay, inside a flux-cored wire, or for a manual welding rod coating [14]. The chemical content of the new flux compound is mainly dictated by the slag system used by the EAF mill to make a specific steel grade [15–17]. The paper [18] shows the effect of flux chemical content obtained by recycling industrial waste from an EAF mill and additives injected into it on the structure and phase and the failure surface of submerged arc weld overlay and welds. The authors of [19] produced a flux compound by electroslag remelting of steel slag from the “Amurstal” Steel Mill, crushing, and binding the components with sodium silicate. Considering the chemical content complexity of the resulting flux, and its unclear heat transfer properties, the purpose of this paper is to find the best energy parameters for submerged arc welding to achieve the normalized weld size. The scope of the study is to determine the effect of submerged arc welding parameters using the tested flux on weld quality: the occurrence of subsurface and surface defects and weld dimensions and the type of the flux effect on the stress-strain response of the weld specimens using commercially available and tested flux. Methods Eight VSt3sp (ASTM A570, Gr. 36) steel sheet welded specimens with a size of 195×440×5 mm (fig. 1, a), having a welded joint type S4 in accordance with GOST 8713–79 – a single-sided single-pass square butt weld with a ceramic backing strip attached to the weld root with a metallized adhesive tape (fig. 1, b) were studied. The workpieces were fitted up without a gap to prevent misalignment, and temporary fixtures (100×40×5 mm, VSt3sp (ASTMA570, Gr. 36) steel) were welded by two short tack welds (10–15 mm). The specimens were welded with a 3 mm GOST 2246-70 Gr. Sv-08A filler wire. A newly invented proprietary welding flux [20] with a grain size of 1.0–4.0 mm, was used as protective barrier for submerged arc welding. Automated welding machine ADF-1250 with power supply VDU-1250 was used for welding at the parameters listed in table 1. Specimen 8 used as a reference was welded using the commercially available welding flux AN-42. We should mention that when welding specimen 1, severe porosity caused by gas emission due to oxidation by flux melting and increased pressure in the interface between the ceramic backing and the specimen was observed. To avoid this adverse effect, 10 mm long slots at 15 mm spacing were cut in the a b Fig. 1. A specimen assembled for welding with a glued ceramic lining: a – general view of the assembled specimen; b – profile of the specimen and the ceramic lining
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