Precipitation Behavior of Vanadium in a High Nitrogen and Vanadium Bearing Steel Treated with TMCP

摘要

A vanadium bearing steel with high nitrogen has been treated with thermomechanical controlled processing. The precipitation was observed in steel samples rolled with different finishing temperatures and cooled with various cooling rates. The results showed that under finishing at 900℃ and air cooling after rolling conditions, few precipitates were found, but large in size. They were recognized as VC and (Ti,V)C by Energy Dispersive Spectrometer. In the process of finishing at 800℃ and water accelerated cooling after rolling, the volume fraction of precipitates was still small, but a large amount of small size dispersive precipitates were found after air cooling. The small precipitates were confirmed as (Ti,V)(C,N) and V(C,N). Influences of austenite deformation and solubility of vanadium in different phases on the vanadium precipitation behavior are analyzed and the vanadium strengthening effects in high nitrogen steel are discussed.