Influence of phosphorus on the hot ductility of 2.25Cr1Mo steel

摘要

The effect of phosphorus at two levels (0.01 and 0.06 wt- percent) on the hot ductility of 2.25Cr1Mo steel has been investigated over the temperature range 700- 1200 deg C using a Gleeble machine. Auger electron spectroscopy indicated that phosphorus segregation to austenite grain boundaries had occurred in the higher phosphorus steel. A trough in the ductility - temperature curve was observed for both steels with the minimum ductility occurring at about 750 deg C. The higher P containing steel gave the worst ductility throughout the temperature range examined. The ductility trough was caused by the formation of a thin pro-eutectoid ferrite layer along austenite grain boundaries, and this trough was accentuated by the presence of phosphorus at the austenite grain boundaries.