The effect of selenium on the oxidation of Fe-Si-Al-C alloy during decarburization at 840 [compositum]C in wet hydrogen was studied. Selenium was found to change the morphology of internal oxides of an Fe-Si-Al-C alloy. The long penetrating internal oxides of Si and Al in the alloy containing 0.034 at.% Se demonstrate an obvious preferential growth perpendicular to the steel substrate. FEG-SEM/EDX was performed to analyze the scale and the subscale. It was assumed that columnar morphology of internal oxides could be induced by selenium surface segregation. Therefore, in-situ AES analysis using a resistive heating of specimen in UHV was used to obtain more accurate data on temperature dependence of selenium surface segregation in silicon steel. Additionally, the kinetics of the selenium surface segregation was investigated in-situ during annealing at 840 [compositum]C in the ultra-high vacuum chamber of a field-emission Auger electron spectrometer.
F.10 Improvements to an existing technological process or technology
COBISS.SI-ID: 878506In the early days of pressurized-water nuclear-power-plant design Ni-based alloys were selected because of their good mechanical properties and corrosion resistance. Alloy 600 was used for some reactor-coolant pressure-boundary components and Alloy 82/182 was used for welds. Industrial experience in the past three decades has shown that Alloy 600 components and Alloy 82/182 welds are susceptible to primary-water stress-corrosion cracking (PWSCC). PWSCC is the intergranular or transgranular cracking due to the combined action of stresses, temperatures and components in contact with the primary water (reactor coolant). PWSCC leaks and cracks were detected on the reactor-coolant pressure-boundary components. In this work some characteristics of the Alloy 600 and Alloy 82/182 welds and their PWSCC degradation are presented.
F.04 Increase of the technological level
COBISS.SI-ID: 857002The report deals with development of technology of cold deformation of autenitic stainless steel at temperature of liquid nitrogen which enables the increase
F.06 Development of a new product
COBISS.SI-ID: 863914