Powder metallurgy superaustenitic stainless steel sintered in N2–H2 atmosphere (95%–5%) was obtained. Three different processes were applied by controlling the sinter-cooling rate (furnace, gas and water). Intergranular corrosion resistance was evaluated. Furthermore, microstructure, density, porosity, macro- and microhardness were investigated. Microstructures were characterised by optical microscopy and scanning electron microscopy with energy dispersive analysis of X-rays. Intergranular corrosion behaviour was evaluated by immersion and by single and double loop electrochemical potentio-kinetic reactivation tests. The superaustenitic steel after fast cooling by water quenching showed the best intergranular corrosion behaviour, the highest microhardness values and the most homogeneous microstructure.
RoadR and LaneT: ‘PM stainless steels uses in automotive exhausts’Met. Powder Rep.19982622–26.
2.
DaverEM and TrombinoCJ: ‘State of the North American PM industry—2006 report’Metal Powder Industries Federation, San Diego, CA, USA2006.
3.
CapusJM: ‘Stainless steel at the 2000 Powder Metallurgy Conference’Adv. Mater. Process.2000957–60.
4.
GarciaCMartinFde TiedraP and García CambroneroL: ‘Pitting corrosion behaviour of PM austenitic stainless steels sintered in nitrogen–hydrogen atmosphere’Corros. Sci.200749, 1718-1736.
5.
GarciaCMartinFde TiedraPBlancoYRuíz-RomanJM and AparicioM: ‘Electrochemical reactivation methods applied to PM austenitic stainless steels sintered in nitrogen–hydrogen atmosphere’Corros. Sci.200850687–697.
6.
DesbiensJRobert-PerronEBlaisC and ChagnonF: ‘Effect of green machining on the tensile properties and fatigue strength of powder metallurgy sinter-hardenable steel components’Mater. Sci. Eng. A2012A546218–222.
7.
ShanmugasundaramD and ChandramouliR: ‘Tensile and impact behaviour of sinter-forged Cr, Ni and Mo alloyed powder metallurgy steels’Mater. Des.200930, 3444-3449.
8.
DobrzańskiLABrytanZActis GrandeM and RossoM: ‘Influence of sintering parameters on the properties of duplex stainless steel’J. Achiev. Mater. Manuf. Eng.200720231–234.
9.
DobrzańskiLABrytanZ and RossoM: ‘Sinter-hardening process applicable to stainless steels’J. Achiev. Mater. Manuf. Eng.20072411–18.
10.
AhmadaFOmarbMA and GermanRM: ‘Effects of cooling rate on mechanical properties and corrosion resistance of vacuum sintered powder injection molded 316L stainless steel’J. Mater. Process. Technol.2012212164–170.
11.
MartinFGarcíaC and BlancoY: ‘Effect of chemical composition and sintering conditions on the mechanical properties of sintered duplex stainless steels’Mater. Sci. Eng. A2011A528, 8500-8511.
12.
NagarajanS and RajendranN: ‘Crevice corrosion behaviour of superaustenitic stainless steels: Dynamic electrochemical impedance spectroscopy and atomic force microscopy studies’Corros. Sci.200951217–224.
13.
HeinoS and KarlssonB: ‘Cyclic deformation and fatigue behaviour of 7Mo–0·5N superaustenitic stainless steel—stress–strain relations and fatigue life’Acta Mater.200149339–351.
14.
SikoraE and MacdonaldDD: ‘Nature of the passive film on nickel’Electrochim. Acta20024869–77.
15.
Abd El AalEE: ‘Breakdown of passive film on nickel in borate solutions containing halide anions’Corros. Sci.200345759–775.
16.
IgualAGarcíaJGuiñonJL and PerezV: ‘Effects of solution temperature on localized corrosion of high nickel content stainless steels and nickel in chromated LiBr solution’Corros. Sci.200648, 3349-3374.
17.
LiljasM: ‘Development of superaustenitic stainless steels’Weld. World19953655–63.
18.
MoriG and BauernfeindD: ‘Pitting and crevice corrosion of superaustenitic stainless steel’Mater. Corros.200455164–173.
19.
FernandesFAPHeckSCPereiraRGPiconCANascentePAP and CastellettiLC: ‘Ion nitriding of a super austenitic stainless steel: Wear and corrosion behaviour’Surf. Coat. Int.2010204, 3087-3090.
20.
HänninenHRomuJIlolaRTervoJ and LaitinenA: ‘Effects of processing and manufacturing of high nitrogen-containing stainless steels on their mechanical, corrosion and wear properties’J. Mater. Process. Technol.2011117424–430.
21.
LewisACBingertJFRowenhorstDJGuptaAGeltmacherAB and SpanosG: ‘Two- and three-dimensional microstructural characterization of a super-austenitic stainless steel’Mater. Sci. Eng. A2006A41811–18.
22.
AnburajJMohamed NazirudeenSSNarayananRAnandavelB and ChandrasekarA: ‘Ageing of forged superaustenitic stainless steel: Precipitate phases and mechanical properties’Mater. Sci. Eng. A2012A53599–107.
23.
KoutsoukisTRedjaïmiaA and FourlarisG: ‘Phase transformations and mechanical properties in heat treated superaustenitic stainless steels’Mater. Sci. Eng. A2013A561477–485.
24.
LópezMDMerinoMCPardoAOtero VillalobosE and UtrillaMV: ‘Estudio de la resistencia a la corrosión localizada del acero inoxidable superaustenítico 24,1Cr22Ni7,1Mo en mezclas que contienen iones cloruro-fluoruro’Rev. Metal. Madrid200137499–508.
25.
AzumaSKudoTMiyukiHYamashitaM and UchidaH: ‘Effect of nickel alloying on crevice corrosion resistance of stainless steels’Corros. Sci.200446, 2265-2280.
26.
JonssonJYWegreliusLHeinoSLiljasM and ÖstbergR: ‘The influence of tungsten (W) on properties in high nitrogen stainless steels’Proc. High Nitrogen Steels ’98; 1998AedermannsdorfTrans Tech Publications Ltd.
27.
RomuJ and HänninenH: ‘Effect of nitrogen content on precipitation during isothermal annealing of P/M high nitrogen austenitic stainless steels’Mater. Sci. Forum1999318-320673–680.
28.
MartínFGarcíaCde TiedraPBlancoY and AparicioML: ‘Sensitization of PM 430L stainless steel sintered in nitrogen-hydrogen atmosphere’Corrosion20086470–82.
29.
GarciaCMartinF and BlancoY: ‘Effect of sintering cooling rate on corrosion resistance of powder metallurgy austenitic, ferritic and duplex stainless steels sintered in nitrogen’Corros. Sci.20126145–52.
30.
‘Standard practice for detecting susceptibility to intergranular attack on austenitic stainless steels’A262-10, ASTM, Philadelphia, PA, USA2011.
31.
‘Standard test method for electrochemical reactivation (EPR) for detecting sensitization of AISI Type 304 and 304L stainless steels’G108-94R10, ASTM, Philadelphia, PA, USA2011.
32.
‘Corrosion of metals and alloys - electrochemical potentiokinetic reactivation measurement using the double loop method (based on Cihal's method)’EN ISO 127322006.
