Chemical inhomogeneity of large forging ingots

The Skoda concern at Pilsen was entrusted with the production of pressure vessels for nuclear reactors. Consequently, the Central Research Institute of the Skoda works became involved in metallurgical research directed toward improving the quality of steels destined for these vessels. In order to determine the optimum forming technology for the 135 t weight ingots used for pressure vessel ring forgings, the macrostructural and chemical inhomogeneities of these ingots were analysed in detail. The target of the research was to verify in detail the distributions of elements tending to segregation as well as the steel purity as to the contents of non metallic inclusions and trace elements, and to determine the optimum forging technology. (author)