It was noted that, in hardness measurements, the indentation depth was about 10% of the effective depth under static loading. A change in the wear mechanism was observed under lateral loading conditions in oscillating ball-on-disc tests of nitrided austenitic stainless steel with an expanded austenite surface layer. It went from abrasive, to sub-surface plastic flow with redistribution of the inserted N. This led to an effective nitriding depth which was some 3 to 5 times greater than the actual nitrided zone.
Interplay of Cold Working and Nitrogen Diffusion in Austenitic Stainless Steel. D.Manova, I.M.Eichentopf, S.Heinrich, S.Mändl, E.Richter, H.Neumann, B.Rauschenbach: Nuclear Instruments and Methods in Physics Research B, 2007, 257[1-2], 442-6
Table 8
Interdiffusion Coefficients in the Fe-Cr-Mo System
Temperature (K) | Cross-Point Composition | Coefficient | Value (m2/s) |
1523 | Fe-4.5Cr-7.1Mo | DCrCrFe | 2.0 x 10-12 |
1523 | Fe-4.5Cr-7.1Mo | DCrMoFe | -9.5 x 10-14 |
1523 | Fe-4.5Cr-7.1Mo | DMoMoFe | 2.0 x 10-12 |
1523 | Fe-4.5Cr-7.1Mo | DMoCrFe | -3.7 x 10-14 |
1523 | Fe-11.8Cr-2.1Mo | DCrCrFe | 1.5 x 10-12 |
1523 | Fe-11.8Cr-2.1Mo | DCrMoFe | -5.9 x 10-13 |
1523 | Fe-11.8Cr-2.1Mo | DMoMoFe | 2.2 x 10-12 |
1523 | Fe-11.8Cr-2.1Mo | DMoCrFe | 9.4 x 10-14 |
1498 | Fe-13.4Cr-1.7Mo | DCrCrFe | 1.4 x 10-12 |
1498 | Fe-13.4Cr-1.7Mo | DCrMoFe | -3.7 x 10-14 |
1498 | Fe-13.4Cr-1.7Mo | DMoMoFe | 1.4 x 10-12 |
1498 | Fe-13.4Cr-1.7Mo | DMoCrFe | -4.2 x 10-14 |