Grain boundary segregation of minor arsenic and nitrogen at elevated temperatures in a microalloyed steel

摘要

Auger electron spectroscopy(AES) was used to investigate the grain boundary segregation of arsenic and nitrogen in a kind of microalloyed steel produced by a compact strip production(CSP) technology at 950 to 1100°C,which are similar to the hot working temperature of the steel on a CSP production line.It was discovered that arsenic segregated on grain boundaries when the steel was annealed at 950°C for 2 h.When the annealing temperature increased to 1100°C,arsenic was also found to have segregated on grain boundaries in the early annealing stage,for instance,within the first 5 min annealing time.However,if the holding time of the steel at this temperature increased to 2 h,arsenic diffused away from grain boundaries into the matrix again.Nitrogen was not found to have segregated on grain boundaries when the steel was annealed at a relatively low temperature,such as 950°C.But when the annealing temperature increased to 1100°C,nitrogen was detected to have segregated at grain boundaries in the steel.