Previous heat treatment inducing different plasma nitriding behaviors in martensitic stainless steels

In this work we report a study of the induced changes in structure and corrosion behavior of martensitic stainless steels nitrided by plasma immersion ion implantation (PI3) at different previous heat treatments. The samples were characterized by x-ray diffraction and glancing angle x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and potentiodynamic measurements. Depending on the proportion of retained austenite in the unimplanted material, different phase transformations are obtained at lower and intermediate temperatures of nitrogen implantation. At higher temperatures, the great mobility of the chromium yields CrN segregations like spots in random distribution, and the α′-martensite is degraded toα-Fe (ferrite). The nitrided layer thickness follows a fairly linear relationship with the temperature and a parabolic law with the process time. The corrosion resistance depends strongly on chromium segregation from the martensitic matrix, as a result of the formation of...

[1]  Zhaoming Zhang,et al.  Structural modifications and corrosion behavior of martensitic stainless steel nitrided by plasma immersion ion implantation , 2005 .

[2]  A. Toro,et al.  Correlations between microstructure and surface properties in a high nitrogen martensitic stainless steel , 2003 .

[3]  M. Fewell,et al.  Characteristics of martensitic stainless steel nitrided in a low-pressure RF plasma , 2003 .

[4]  J. P. Espinós,et al.  Experimental Evidences of New Nitrogen-Containing Phases in Nitrided Steels , 2002 .

[5]  C. Figueroa,et al.  Effect of hydrogen and oxygen on stainless steel nitriding , 2002 .

[6]  Zhi-wei Yu,et al.  Structural characteristics of low-temperature plasma-nitrided layers on AISI 304 stainless steel with an α'-martensite layer , 2002 .

[7]  A. F. Beloto,et al.  Plasma immersion ion implantation experiments at the Instituto Nacional de Pesquisas Espaciais (INPE), Brazil , 2001 .

[8]  K. Short,et al.  Nitrogen and carbon expanded austenite produced by PI3 , 2001 .

[9]  M. Fewell,et al.  Nitriding at low temperature , 2000 .

[10]  M. Fewell,et al.  Low pressure r.f. nitriding of austenitic stainless steel in an industrial-style heat-treatment furnace , 1999 .

[11]  T. Bell,et al.  Sliding wear characteristics of low temperature plasma nitrided 316 austenitic stainless steel , 1998 .

[12]  K. Short,et al.  Ion-assisted surface modification by plasma immersion ion implantation , 1998 .

[13]  K. Short,et al.  Influence of process parameters on the nitriding of steels by plasma immersion ion implantation , 1998 .

[14]  W. Möller,et al.  Nitriding of austenitic stainless steels using plasma immersion ion implantation , 1998 .

[15]  B. Mordike,et al.  Industrial applications of plasma immersion ion implantation , 1997 .

[16]  M. Fewell,et al.  The Low-Pressure Rf Plasma as a Medium for Nitriding Iron and Steel , 1997 .

[17]  L. Stals,et al.  A diffusion model of metal surface modification during plasma nitriding , 1996 .

[18]  K. Short,et al.  Nitriding of austenitic stainless steel by plasma immersion ion implantation , 1995 .

[19]  G. Collins,et al.  Microstructure, corrosion and tribological behaviour of plasma immersion ion-implanted austenitic stainless steel , 1993 .

[20]  J. R. Conrad,et al.  Plasma source ion-implantation technique for surface modification of materials , 1987 .

[21]  C. Figueroa,et al.  Identification of the mechanism-limiting nitrogen diffusion in metallic alloys by in situ photoemission electron spectroscopy , 2003 .

[22]  L. Reimer,et al.  Scanning Electron Microscopy , 1984 .

[23]  H. Aaronson,et al.  Precipitation processes in solids : proceedings of a symposium sponsored by the TMS-AIME Heat Treatment Committee at the 1976 TMS Fall Meeting af Niagara Falls, New York, September 20, 21. , 1978 .