The determination of alloying and impurity elements was performed from a stainless steel matrix and inclusions in process samples. An electrolytic extraction method was applied for the separation of inclusions using two different but commonly used electrolytes, 10% HCl and 10% acetylacetone in methanol. The elemental analyses were performed using atomic absorption spectrometry. The elements of interest were aluminum, arsenic, copper, vanadium, titanium and chromium. The aluminum containing inclusions were imaged using a field emission scanning electron microscope. The results for copper and chromium in both electrolytes, vanadium in 10% HCl electrolyte and arsenic in 10% acetylacetone electrolyte were in good agreement with industrial data. Titanium and aluminum were measured from the dissolved steel matrix but titanium was also detected in the inclusions. It was concluded that the analytical results for titanium and aluminum measured using an optical emission spectrometer is affected by the inclusions within the stainless steel.

TEIJA SIPOLA, TUOMAS ALATARVAS, EETU-PEKKA HEIKKINEN, and TIMO FABRITIUS Chromium, nickel, and manganese are common alloying elements in stainless steels. Additionally, titanium and niobium are added as microalloying elements to certain stainless steel grades. A double-stabilized stainless steel sample was dissolved in electrolyte using an electrolytic extraction method. Inclusions were separated from the electrolyte with vacuum filtration and put through a separate elemental analysis. Steel-soluble alloying elements were determined from the electrolyte after the extraction, and the elemental analysis of inclusions was performed. The results were compared to the ones obtained from the surface analysis commonly used in the steel industry. It was concluded that the alloying elements were distributed between inclusions and the steel matrix. Therefore, optical emission analysis from a solid steel sample can be misleading. The results might not accurately depict the composition of the steel matrix. Electrolytic extraction methods combined with elemental analysis provide accurate information about the real matrix composition of microalloying elements in steel. The method is also a tool for the simultaneous analysis of inclusions in 3D and soluble alloying elements.