Study of multicomponent segregation at interfaces in high-strength skelp steel

Rolled plates of high-strength skelp steel 05G2NDMFBT with a thickness of 30.9 mm and a strength rating of X70 were studied after two-stage thermomechanical treatment with accelerated cooling. Auger electron spectroscopy was used to study the temperature-time intervals associated with the segregation of carbon, nitrogen, sulfur, and phosphorus in specimens cut out from the surface and mid-thickness of the plates. Electron spectra were recorded after certain time intervals during isothermal holds (ranging from 300 to 8000 sec in duration). The article presents diagrams describing the isothermal segregation of carbon, nitrogen, sulfur, and phosphorus at 120, 200, 300, 355, 400, and 600°C and the main temperature-time intervals in which these elements tend to segregate in the grain boundaries of the steel.