Influence of nitrogen-alloying on the tempering properties of the martensitic stainless steel 00Cr13Ni4Mo

摘要

The mechanical and corrosive properties of 00Cr13Ni4Mo(S13-4N) were tested and compared with those of 00Cr13Ni6Mo(S13-6).The effects of nitrogen on the properties of the steels were analyzed.The results of the tensile and corrosion tests show the strength,the ductility,and the pitting corrosion resistance of S13-4N are higher,lower and poorer than those of S13-6 respectively,when tempered at a temperature below 550℃and vice versa when the tempering temperature is higher than 550℃.The results of the X-ray diffraction(XRD) and the electron backscattered diffraction (EBSD) analyses reveal that inversed austenite appears at 550℃and the amount of it peaks at 600℃with the best ductility.And the total amount of the inversed austenite in S13-6 is more than that in S13-4N in different forms. Nitrogen performs better in terms of stabilizing inversed austenite while nickel is more favorable for forming inversed austenite,the amount and stability of which affect the ductility remarkably.The reason for the embrittlement of S13-4N at 450℃can be the result of carbide and nitride precipitating at grain boundaries.