Pinedo et al.77 Pinedo CE, Varela LB, Tschiptschin AP. Low-temperature plasma nitriding of AISI F51 duplex stainless steel. Surf Coat Tech. 2013;232:839-43. http://dx.doi.org/10.1016/j.surfcoat.2013.06.109. http://dx.doi.org/10.1016/j.surfcoat.201...
|
d.c. |
UNS S31803 |
20 |
400 |
Formation of a two-phase γN + αN layer with 3.8 and 4.4 wt.% N, respectively (αN thicker than γN, both with microhardness > 1350 HV). |
Tschiptschin et al.88 Tschiptschin AP, Varela LB, Pinedo CE, Li XY, Dong H. Development and microstructure characterization of single and duplex nitriding of UNS S31803 duplex stainless steel. Surf Coat Tech. 2017;327:83-92. http://dx.doi.org/10.1016/j.surfcoat.2017.08.018. http://dx.doi.org/10.1016/j.surfcoat.201...
|
d.c. |
UNS S31803 |
20 |
400 |
Formation of a two-phase γN + αN layer, with 3.0 and 2.5 μm thickness, and 1360 HV and 1510 HV microhardness, respectively (intense coherent ε-Fe3N nitride precipitation inside αN). |
Larisch et al.1616 Larisch B, Brusky U, Spies H-J. Plasma nitriding of stainless steels at low temperatures. Surf Coat Tech. 1999;116–119:205-11. http://dx.doi.org/10.1016/S0257-8972(99)00084-5. http://dx.doi.org/10.1016/S0257-8972(99)...
|
Gas nitriding |
UNS S31803 |
3 to 12 |
400 to 550 |
Formation of a two-phase γN + αN layer formed in austenite and ferrite grains, respectively. |
Calabokis et al.1717 Calabokis OP, Núñez de la Rosa Y, Lepienski CM, Cardoso RP, Borges PC. Crevice and pitting corrosion of low temperature plasma nitrided UNS S32750 super duplex stainless steel. Surf Coat Tech. 2021;413:127095. http://dx.doi.org/10.1016/j.surfcoat.2021.127095. http://dx.doi.org/10.1016/j.surfcoat.202...
|
d.c. (LTPN) |
UNS S32750 |
4 |
350, 400 |
Formation of a precipitation-free single-phase γN layer with significant corrosion resistance performance improvements for all treatment conditions. |
Bielawski and Baranowska1818 Bielawski J, Baranowska J. Formation of nitrided layers on duplex steel – influence of multiphase substrate. Surf Eng. 2010;26(4):299-305. http://dx.doi.org/10.1179/026708410X12593178265904. http://dx.doi.org/10.1179/026708410X1259...
|
d.c. |
UNS S31803 |
8 to 60 |
250 to 500 |
Formation of precipitation-free single-phase γN layer, with thickness of 15 μm and 8.9 wt.% N produced at temperatures up to 400 °C. |
Kliauga and Pohl1919 Kliauga AM, Pohl M. Effect of plasma nitriding on wear and pitting corrosion resistance of X2 CrNiMoN 22 5 3 duplex stainless steel. Surf Coat Tech. 1998;9(1-3):1205-10. http://dx.doi.org/10.1016/S0257-8972(97)00240-5. http://dx.doi.org/10.1016/S0257-8972(97)...
|
high-frequency pulsed plasma |
UNS S31803 |
20 and 40 |
350 and 400 |
At 350 °C, the layer homogeneously covers the ferrite and the austenite phase regions, the latter phase showing γN formation, and needle-like α′′-Fe16N2 precipitation occurring in the layer-ferrite phase interface. At 400°C, Cr2N + Fe2-3N + γ'-Fe4N nitrides were present in the layer showing cracks. |
Blawert et al.2020 Blawert C, Mordike BL, Jirásková Y, Schneeweiss O. Structure and composition of expanded austenite produced by nitrogen plasma immersion ion implantation of stainless steels X6CrNiTi1810 and X2CrNiMoN2253. Surf Coat Tech. 1999;116–119:189-98. http://dx.doi.org/10.1016/S0257-8972(99)00086-9. http://dx.doi.org/10.1016/S0257-8972(99)...
|
PI33 Mandrino D, Donik C. Chemical-state information obtained by AES and XPS from thin oxide layers on duplex stainless steel surfaces. Vacuum. 2011;86(1):18-22. http://dx.doi.org/10.1016/j.vacuum.2011.03.025. http://dx.doi.org/10.1016/j.vacuum.2011....
|
UNS S31803 |
3 |
400 |
The pre-existing ferrite phase transforms into γN phase, which in the extreme surface decomposes into ferrite + martensite + CrN. |
Li et al.2121 Li X, Dou W, Tian L, Dong H. Combating the tribo-corrosion of LDX2404 lean duplex stainless steel by low temperature plasma nitriding. Lubricants. 2018;6(4):93. http://dx.doi.org/10.3390/lubricants6040093. http://dx.doi.org/10.3390/lubricants6040...
|
d.c. |
UNS S82441 |
10 |
390 to 480 |
The original austenite phase become γN phase, and the ferrite phase is supersaturated with N forming ε-Fe3N nitride precipitates. |
Chiu et al.2222 Chiu LH, Su YY, Chen FS, Chang H. Microstructure and properties of active screen plasma nitrided duplex stainless steel. Mater Manuf Process. 2010;25(5):316-23. http://dx.doi.org/10.1080/10426911003748020. http://dx.doi.org/10.1080/10426911003748...
|
ASPN |
UNS S31803 |
10 to 25 |
400 to 450 |
At 420 °C, a two-phase γN and αN layer is formed, and at 435 and 450 °C, Fe and Cr nitrides precipitate in the layer. |
Nagatsuka et al.2323 Nagatsuka K, Nishimoto A, Akamatsu K. Surface hardening of duplex stainless steel by low temperature active screen plasma nitriding. Surf Coat Tech. 2010;205:S295-9. http://dx.doi.org/10.1016/j.surfcoat.2010.08.012. http://dx.doi.org/10.1016/j.surfcoat.201...
|
ASPN and d.c. |
UNS S32550 |
5 |
400 and 450 |
Single-phase γN layer is obtained (in austenite as well as in ferrite phases) on both d.c. and ASPN samples treated at 400 and 450 °C. |
Alphonsa et al.2424 Alphonsa J, Raja VS, Mukherjee S. Study of plasma nitriding and nitrocarburizing for higher corrosion resistance and hardness of 2205 duplex stainless steel. Corros Sci. 2015;100:121-32. http://dx.doi.org/10.1016/j.corsci.2015.07.014. http://dx.doi.org/10.1016/j.corsci.2015....
|
d.c. |
UNS S32205 |
4 |
350 to 500 |
GIXRD results show that at 350 and 400°C only γN phase is present in the layer and that at 450 and 500 °C Fe3N and CrN phases form. |
Assmann et al.2525 Assmann A, Foerster CE, Serbena FC, Lepienski CM, Chinelatto AL. Mechanical and tribological properties of LDX2101 duplex stainless steel submitted to glow discharge ion nitriding. IEEE Trans Plasma Sci. 2011;39(11):3108-14. http://dx.doi.org/10.1109/TPS.2011.2162344. http://dx.doi.org/10.1109/TPS.2011.21623...
|
GDN and CIBNI |
UNS S32101 |
3 |
300, 350 and 380 |
Α γN layer with nitride precipitation arising from 300 °C, with 1220 HV microhardness is obtained for the poor nitrogen atmosphere GD process. The CIBNI process even at high temperature produced only nitrogen-expanded austenite. |
Blawert et al.2626 Blawert C, Weisheit A, Mordike BL, Knoop RM. Plasma immersion ion implantation of stainless steel: austenitic stainless steel in comparison to austenitic-ferritic stainless steel. Surf Coat Tech. 1996;85(1-2):15-27. http://dx.doi.org/10.1016/0257-8972(96)02880-0. http://dx.doi.org/10.1016/0257-8972(96)0...
|
PI33 Mandrino D, Donik C. Chemical-state information obtained by AES and XPS from thin oxide layers on duplex stainless steel surfaces. Vacuum. 2011;86(1):18-22. http://dx.doi.org/10.1016/j.vacuum.2011.03.025. http://dx.doi.org/10.1016/j.vacuum.2011....
|
UNS S31803 |
1, 3 and 7 |
200,400 and 500 |
Single-phase γN layer is formed on both austenite and ferrite grains. |
Oliveira et al.2727 Oliveira WR, Kurelo BCES, Ditzel DG, Serbena FC, Foerster CE, Souza GB. On the S-phase formation and the balanced plasma nitriding of austenitic-ferritic super duplex stainless steel. Appl Surf Sci. 2018;434:1161-74. http://dx.doi.org/10.1016/j.apsusc.2017.11.021. http://dx.doi.org/10.1016/j.apsusc.2017....
|
PI33 Mandrino D, Donik C. Chemical-state information obtained by AES and XPS from thin oxide layers on duplex stainless steel surfaces. Vacuum. 2011;86(1):18-22. http://dx.doi.org/10.1016/j.vacuum.2011.03.025. http://dx.doi.org/10.1016/j.vacuum.2011....
|
UNS S32750 |
3 |
292 to 401 |
ε-Fe2-3N and γ-Fe4N iron nitrides are formed in the modified ferrite grains, whereas γN was produced mostly in austenite grains. Overall near surface microhardness is increased from 610 to 1530 HV. |
Bobadilla and Tschiptschin2828 Bobadilla M, Tschiptschin A. On the nitrogen diffusion in a duplex stainless steel. Mater Res. 2015;18(2):390-4. http://dx.doi.org/10.1590/1516-1439.337714. http://dx.doi.org/10.1590/1516-1439.3377...
|
d.c. |
UNS S31803 |
4 |
350 to 500 |
The non-unidirectional N diffusion tends to result in a N diffusion flow from ferrite to austenite, leading to the formation of a duplex γN + αN layer with small thickness difference in both phases. |