The combined effect of molybdenum and nitrogen on the fatigued microstructure of 316 type austenitic stainless steel

• Published in: Scripta materialia Vol. 41; no. 5; pp. 467 - 473
• Main Authors: Murayama, M, Hono, K, Hirukawa, H, Ohmura, T, Matsuoka, S
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 06.08.1999; Elsevier Science
• Subjects: Applied sciences; Atom probe; Austenite steel; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fatigue; Fatigue, corrosion fatigue, embrittlement, cracking, fracture and failure; Fatigue, embrittlement, and fracture; Field ion microscope; Materials science; Metals. Metallurgy; Physics; TEM; Treatment of materials and its effects on microstructure and properties; Fatigue; Field ion microscope; Austenite steel; Atom probe; TEM; Plastic fatigue; Austenitic stainless steel; Property composition relationship; Mechanical properties; Experimental study; Crack propagation; Stainless steel-316; Nitrogen additions; Property structure relationship; Field emission ion microscopy; Steels; Microstructure; Fatigue cracks
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/S1359-6462(99)00194-3

The mechanism of the improved fatigue crack growth properties of SUS316 austenitic stainless steels by nitrogen addition has been investigated by comparing the fatigue properties of the modified SUS316 based steels with and without Mo and N. Transmission electron microscope (TEM) observations of the dislocation structures and APFIM analysis results suggest that this effect is not only due to the single addition of nitrogen, but also is due to the interactions between Mo and N atoms. FIM and atom probe results strongly suggest that there are Mo-N pairs in the nitrogen containing SUS316 stainless steel, and TEM observation results show that planar array of dislocations only in the Mo-N containing specimens. These results suggest that the stacking fault energy alone cannot explain the change in the fatigue properties, but the presence of Mo-N atomic pairs would also influence the dislocation microstructure.