In the previous study, however, it was unclear what effect deoxidation
had on improved filiform corrosion resistance as part of the conversion-coating process.
The experimental results show that melting of the investigated materials is accompanied by denitriding of the metal (denitriding is intensive in the deoxidation
period of the preliminary stage, and only slight in the final stage).
It is therefore very important to know the optimum amount of aluminium, introduced in the preliminary deoxidation
Chemical Composition--Chemical composition determines if the filter will be vulnerable to attack by slag, deoxidation
products and other aggressive chemicals in the molten metal that can weaken or chemically attack the filter.
Boiling of the slag which takes place in this case should, on the one hand, intensify the mass exchange processes in the volume of the slag, including the removal or nitrogen and, on the other hand, deoxidation
of the surface with carbon reduces the dip in the degree of oxidation and they should have the directly opposite effect on the final nitrogen content.
with carbon in melting in argon leads to the formation of porosity in ingots.
The so-called primary nonmetallic inclusions based on the oxide phases form in the liquid metal when adding the deoxidation
elements in all stages of preliminary deoxidation
(alloying with active elements) and also in the furnace-ladle system and in the vacuum treatment stage.
and alloying practice, Al can reduce all oxides in the slag, leading to Si and manganese reversion and the corresponding loss of Al from the steel as it reacts with [SiO.
By means of change of activities of the deoxidizers in course of deoxidation
of molten steel and during solidification of the metal, crystallization and solid-phase reactions of formation of oxide phases occur in certain areas of phase equilibriums of the CaO-MgO-[Al.
of copper alloys by phos-copper additions is a common practice (typically 1-3 oz phos-copper/100 lb metal just prior to pouring).
Under conditions of <<Dneprospetsstal>> Works the steels of ShKh15 and ShKh15SG-V grades are melted in basic arc electric furnaces DSP-50 with next alloying by carbon ferromanganese (DSTU 3547-97), ferrosilicium FS65 (DSTU 4127-2002), deoxidation
and desulphurization in installation <<furnace-ladle>> (IFL) under slag melt of CaO-[CaF.
The final deoxidation
of the heat was done by adding pellets of aluminum to the tapping stream at the rate of 2 lb/ton.