Steel 08Kh18N10T-VO for Power Generation Equipment Components

Abstract

For manufacturing billets for power generation equipment components with prolonged service life at elevated temperatures, especially pure steel 08Kh18N10T is required. The technology of melting steel grade 08Kh18N10T-VO with thorough vacuum decarburization makes it possible to prepare large forging ingots at 70°C above the liquidus temperature. A study of billet metal shows that titanium carbonitride and carbosulfide make up 85–100% of nonmetallic inclusions in steel grade 08Kh18N10T-VO. With sulphur content reduced from 0.006 to 0.0026%, the amount of carbosulfide decreases by a factor of seven. With a sulphur content of 0.0026% there is no extensive titanium carbosulfide (Ti₄C₂S₂). The grain size in component workpieces corresponds to points 3–5 according to GOST 5639. Mechanical properties at 20 and 350°C are better than specified in technical documents.