The master’s thesis presents the optimisation of the technological cut-off of billets, which were hot rolled from V11 ingots. The formation of porosity, chemical reactions and favourable conditions for the formation of non-metallic inclusions and the consequences they have on the steel quality. The quality is also affected by the problem of segregations of chemical elements. The master thesis also describes the procedure of ingot casting and hot rolling of billets.
As part of the research, we analysed eight ingots, which were cast from two batches of OCR12VM quality steel in the steel plan of the company Metal Ravne. We studied the influence of the use of different exothermic insulation coatings in the mould head on the steel purity. The analyses were performed on billets with a cross-section of 130 mm × 130 mm and five cuts at the head of the billets were examined on each of them. Non-metallic inclusions were classified according to the K method, based on the DIN 50602 standard and method A, based on the ASTM E45.
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