scholarly journals Accessing the full spectrum of corrosion behaviour of tempered type 420 stainless steel

Author(s):  
Yiqi Zhou ◽  
Dirk Lars Engelberg
Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 794 ◽  
Author(s):  
Yiqi Zhou ◽  
Dirk Lars Engelberg

Bipolar electrochemistry has been applied to Type 420 ferritic stainless steel in order to determine the full spectrum of anodic-to-cathodic polarisation behaviour. The occurrence of crevice corrosion, pitting corrosion in combination with general corrosion, pitting corrosion only, general corrosion only, followed by a cathodic region has been observed. Instances of pitting corrosion initiated near chromium-rich carbides with Cr23C6, Cr3C2, and Cr7C3 identified as pit nucleation sites. The observed pit growth kinetics were independent of the electrochemical over-potential. Characterisation of the pit size distributions supports the presence of a critical dissolved volume for the transition of metastable to stable pit growth and pit coalescence.


2015 ◽  
Vol 39 (3-4) ◽  
pp. 167-174
Author(s):  
Michal Latkiewicz ◽  
Halina Krawiec ◽  
Vincent Vignal ◽  
Paulina Erazmus-Vignal

Author(s):  
Srikant Tiwari ◽  
Suryanarayan B Mishra

Artificial material such as stainless steel (SS) is widely used for orthopaedic applications owing to its superior properties, ease of fabrication and lower cost. However, in the body environment, stainless steel can leach toxic elements such as nickel and chromium. To prevent this, a hydroxyapatite (HAp) coating having chemical characteristics very similar to the human bone was deposited on a medical-grade UNS S31254 austenitic stainless steel by a Low-velocity oxy-fuel spray gun (LVOF). The coating was characterised by using a field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and Fourier transform infrared spectroscope (FTIR). The adhesion strength, microhardness and corrosion behaviour were studied using the Tensometre, Vickers microhardness tester and potentiodynamic polarisation with electrochemical impedance spectroscope. The bacterial adhesion and bioactivity of the coating were also evaluated. The LVOF sprayed HAp coating has shown better corrosion resistance, higher bioactivity and higher hardness than the uncoated steel. The presence of tricalcium phosphate, octa-calcium phosphate (OCP) and tetra-calcium phosphate (TTCP) was found in the coating. LVOF sprayed HAp coating is also found suitable in lowering the bacterial adhesion on the steel substrate.


1987 ◽  
Vol 112 ◽  
Author(s):  
Masaki Tsukamoto ◽  
Inga-Kari Björner ◽  
Hilbert Christensen ◽  
Hans-Peter Hermansson ◽  
Lars Werme

AbstractThe release of Am-241 during corrosion of the radioactive waste glass, JSS-A, has been studied in the presence of corrosion products and/or uncom-pacted bentonite. The corrosion behaviour of Am-241 has been analyzed using gamma spectrometry. Adsorption of Am-241 on bentonite is observed in all cases. The contents of Am-241 in centrifuged leachates are in most cases less than 1/100 of total values. The normalized elemental mass loss of Am increases initially with corrosion time, and the values in the presence of bentonite and corrosion products are larger than those in the presence of bentonite alone. This tendency is in agreement with results previously found for other elements. The release of Am is low, only about 10–20 % of the corresponding total mass loss.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 119
Author(s):  
Dana H. Abdeen ◽  
Muataz A. Atieh ◽  
Belabbes Merzougui

The inhibition behavior of carbon nanotubes (CNTs) and Gum Arabic (GA) on the corrosion of 316L stainless steel in CNTs–water nanofluid under the effect of different temperatures was investigated by electrochemical methods and surface analysis techniques. Thereby, 316L stainless steel samples were exposed to CNTs–water nanofluid under temperatures of 22, 40, 60 and 80 °C. Two concentrations of the CNTs (0.1 and 1.0 wt.% CNTs) were homogenously dispersed in deionized water using the surfactant GA and tested using three corrosion tests conducted in series: open circuit test, polarization resistance test, and potentiodynamic scans. These tests were also conducted on the same steel but in solutions of GA-deionized water only. Tests revealed that corrosion increases with temperature and concentration of the CNTs–water nanofluids, having the highest corrosion rate of 32.66 milli-mpy (milli-mil per year) for the 1.0 wt.% CNT nanofluid at 80 °C. In addition, SEM observations showed pits formation around areas of accumulated CNTs that added extra roughness to the steel sample. The activation energy analysis and optical surface observations have revealed that CNTs can desorb at higher temperatures, which makes the surface more vulnerable to corrosion attack.


CORROSION ◽  
10.5006/3763 ◽  
2021 ◽  
Author(s):  
Danbin Jia ◽  
Liangcai Zhong ◽  
Jingkun Yu ◽  
Zhaoyang Liu ◽  
Yuting Zhou ◽  
...  

The effects of morphology of ferrite and non-metallic inclusions on corrosion resistance of as-cast 304 stainless steel (304 SS) were investigated. With the decrease in quenching temperature from 1723 K to 1648 K, the different microstructures of the as-cast 304 SS were obtained as the following series: austenitic-lathy δ ferrite, austenitic-colony δ ferrite and austenitic-blocky δ ferrite, and the average inclusion size increased. The electrochemical results show that the sample with the microstructure of austenitic- lathy δ ferrite and smaller size inclusions had a higher corrosion tendency and the lower pitting resistance. Furthermore, the effect of morphology and content of ferrite on corrosion resistance was greater than that of inclusion size under the current experimental conditions. Therefore, a promising method was developed to improve the corrosion resistance of as-cast 304 SS by changing the solidification process.


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