The paper presents numerical modelling and an operational experiment to forge a slab ingot P40N from 55NiCrMoV7 tool steel and the procedure for the optimization of its production. The aim of the numerical simulation of forging was to verify the existing procedure of forging a plate from a conventional polygonal 8K forging ingot and a slab ingot with a polygonal shape of P40N surfaces. The effect of the shape of the ingot on the achievement of the required forging reduction and strain after the cross section of the forging of the plate, with final dimensions of approximately 1010 mm width × 310 mm thickness × 5350 mm length, was studied. The results obtained in the operational experiment showed satisfactory qualitative parameters of the steel forging from the slab P40N ingot which were in accordance with the predicted results of numerical simulations. The results indicated that in selected cases the use of a slab P40N ingot instead of the conventional polygonal 8K forging ingot can be considered in the production of certain plate-type forgings.
The prospects of processing blast furnace and steelmaking sludge using Waelz process in a laboratory rotary kiln is shown. The influence of varying thermal treatment modes, furnace atmosphere and type of reducing agents on the level of zinc reduction from sludges was analyzed. In general, the blast furnace sludge contains a high portion of iron (approx.48 wt. %) and can be reused as a charge after satisfactory zinc reduction. It was found that N- atmosphere and high content of the graphite or coke oven reducing agent in combination with high temperature can reduce the content of Zn in the sludge to 0.08 wt. % at 1200 °C for mixture of steelmaking and blast furnace sludge. A significant reduction in the Zn content to 0.66 wt. % occurs at 1100 °C. The content and type of reducing agent play an important role; graphite has shown a better reducing ability compared to coke oven dust. When nitrogen is used, zinc is reduced even without an additional reducing agent, since the carbon contained in the sludge is made use of for the reduction. In an air atmosphere, without the use of a reducing agent, there was no reduction in the Zn content.
The quality production technology for the WNr. 1.8504 steel was developed. The aim of the work was to achieve the required internal micro-purity and determine the effects of different production technologies on the qualitative parameters of forged-steel pieces. Firstly, polygonal ingots weighing 1600 kg were produced, using the metallurgical units, in a controlled-atmosphere induction-melting furnace (IF) without vacuum treatment, and in a vacuum and pressurized induction-melting furnace (VPIM) with vacuum treatment. The ingots were subsequently reshaped by open-die forging into bars with a rectangular cross-section. The effect of the ingot-production technology was evaluated by comparing the forged-steel pieces in terms of their purity, macrostructure and microstructure. Keywords: vacuum, inclusion, aluminium, steel Izvr{en je bil razvoj kakovostne proizvodne tehnologije jekla W.Nr. 1.8504. Namen je bil dose~i`eleno notranjo mikro~isto~o in ugotoviti vpliv razli~nih tehnologij proizvodnje na kvalitativne parametre odkovkov. Najprej so bili izdelani poligonalni kovani ingoti z maso 1600 kg, z uporabo naslednjih metalur{kih agregatov: v indukcijski talilni pe~i s kontrolirano atmosfero (IF) brez vakuumskega rafiniranja in v vakuumski ter indukcijski talilni pe~i (VPIM) s povi{anim tlakom in z vakuumskim rafiniranjem. Nato so bili ingoti s prostim kovanjem preoblikovani v palice s pravokotnim prerezom. Vpliv tehnologije proizvodnje ingotov je bil ocenjen s primerjavo odkovkov z vidika~istosti, makro in mikrostrukture.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.