The influence of cerium, yttrium and lanthanum ion implantation on the oxidation behaviour of a 20Cr25NiNb stainless steel in carbon dioxide at 900–1050°C

1987 ◽  
Vol 90 ◽  
pp. 177-190 ◽  
Author(s):  
M.J. Bennett ◽  
H.E. Bishop ◽  
P.R. Chalker ◽  
A.T. Tuson
Keyword(s):  
Carbon Dioxide ◽  
Stainless Steel ◽  
Ion Implantation ◽  
Oxidation Behaviour ◽  
Lanthanum Ion

The Effects of Yttrium Ion Implantation Upon the Oxidation Behaviour of an Austenitic Stainless Steel

1973 ◽  
pp. 415-422 ◽  
Author(s):  
J. E. Antill ◽  
M. J. Bennett ◽  
G. Dearnaley ◽  
F. H. Fern ◽  
P. D. Goode ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ion Implantation ◽  
Oxidation Behaviour ◽  
Yttrium Ion

Influence of ion implantation on the microstructure of oxide scales formed on a 20Cr/25Ni/Nb-stabilized stainless steel in carbon dioxide at 825° C

1987 ◽  
Vol 22 (2) ◽  
pp. 449-458 ◽  
Author(s):  
C. H. Yang ◽  
P. A. Labun ◽  
G. Welsch ◽  
T. E. Mitchell ◽  
M. J. Bennett
Keyword(s):  
Carbon Dioxide ◽  
Stainless Steel ◽  
Ion Implantation ◽  
Oxide Scales

Improvement by cerium and yttrium ion implantation of the oxidation behaviour of a 20Cr25Ni Niobium-stabilized stainless steel in CO2

1985 ◽  
Vol 69 (2) ◽  
pp. 359-373 ◽  
Author(s):  
M.J. Bennett ◽  
B.A. Bellamy ◽  
C.F. Knights ◽  
Nicola Meadows ◽  
N.J. Eyre
Keyword(s):  
Stainless Steel ◽  
Ion Implantation ◽  
Oxidation Behaviour ◽  
Yttrium Ion

Yttrium Location and Chemical State in the Scale Formed On Y–Implanted 20%Cr/25%Ni/Nb Stabilised Stainless Steel in Carbon Dioxide at 825 C

1985 ◽  
Vol 43 ◽  
pp. 270-271 ◽  
Author(s):  
M.J. Bennett ◽  
J.A. Desport ◽  
P.A. Labun
Keyword(s):  
Carbon Dioxide ◽  
Stainless Steel ◽  
Ion Implantation ◽  
Analytical Electron Microscopy ◽  
Chemical State ◽  
Temperature Oxidation ◽  
Initial Stage ◽  
Extended Exposure ◽  
Microscopy Examination

Understanding how the so-called reactive elements improve the protection afforded to alloys by Cr203 and Al203 scales continues to be a major topic of high temperature oxidation research. Considerable progress has stemmed from studies on alloy surfaces modified by the controlled addition of these elements, such as yttrium and cerium, by ion implantation. The influence of yttrium ion implantation upon the oxidation behaviour of the technologically important 20%Cr/25%Ni/0.7%Mn/0.7%Si/Nb stabilised (20/25/Nb) austenitic stainless steel in carbon dioxide at 825°C has been the subject of extensive investigation. The implantation of 1017 yttrium ions cm-2 reduced the overall attack of the 20/25/Nb steel and maintained scale adhesion during extended exposure (6500h). These effects derived from the initial stage (<1h) of scale development.Further mechanistic understanding of the role of yttrium is critically dependent upon ascertaining both its location within the scale and its chemical state. This paper reports the preliminary results from an analytical electron microscopy examination of both back thinned(planar) and transverse sections of scales formed on yttrium implanted 20/25/Nb steel following 775 and 6500h oxidation in carbon dioxide at 825°C respectively.

scholarly journals Effect of Nitrogen Ion Implantation on the Cavitation Erosion Resistance and Cobalt-Based Solid Solution Phase Transformations of HIPed Stellite 6

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2324
Author(s):  
Mirosław Szala ◽  
Dariusz Chocyk ◽  
Anna Skic ◽  
Mariusz Kamiński ◽  
Wojciech Macek ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Ion Implantation ◽  
Phase Transformations ◽  
Erosion Rate ◽  
Cavitation Erosion ◽  
Matrix Phase ◽  
Nitrogen Ion Implantation ◽  
Stellite 6 ◽  
Nitrogen Ion

From the wide range of engineering materials traditional Stellite 6 (cobalt alloy) exhibits excellent resistance to cavitation erosion (CE). Nonetheless, the influence of ion implantation of cobalt alloys on the CE behaviour has not been completely clarified by the literature. Thus, this work investigates the effect of nitrogen ion implantation (NII) of HIPed Stellite 6 on the improvement of resistance to CE. Finally, the cobalt-rich matrix phase transformations due to both NII and cavitation load were studied. The CE resistance of stellites ion-implanted by 120 keV N+ ions two fluences: 5 × 1016 cm−2 and 1 × 1017 cm−2 were comparatively analysed with the unimplanted stellite and AISI 304 stainless steel. CE tests were conducted according to ASTM G32 with stationary specimen method. Erosion rate curves and mean depth of erosion confirm that the nitrogen-implanted HIPed Stellite 6 two times exceeds the resistance to CE than unimplanted stellite, and has almost ten times higher CE reference than stainless steel. The X-ray diffraction (XRD) confirms that NII of HIPed Stellite 6 favours transformation of the ε(hcp) to γ(fcc) structure. Unimplanted stellite ε-rich matrix is less prone to plastic deformation than γ and consequently, increase of γ phase effectively holds carbides in cobalt matrix and prevents Cr7C3 debonding. This phenomenon elongates three times the CE incubation stage, slows erosion rate and mitigates the material loss. Metastable γ structure formed by ion implantation consumes the cavitation load for work-hardening and γ → ε martensitic transformation. In further CE stages, phases transform as for unimplanted alloy namely, the cavitation-inducted recovery process, removal of strain, dislocations resulting in increase of γ phase. The CE mechanism was investigated using a surface profilometer, atomic force microscopy, SEM-EDS and XRD. HIPed Stellite 6 wear behaviour relies on the plastic deformation of cobalt matrix, starting at Cr7C3/matrix interfaces. Once the Cr7C3 particles lose from the matrix restrain, they debond from matrix and are removed from the material. Carbides detachment creates cavitation pits which initiate cracks propagation through cobalt matrix, that leads to loss of matrix phase and as a result the CE proceeds with a detachment of massive chunk of materials.

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