Electrochemical polishing as a 316L stainless steel surface treatment method: Towards the improvement of biocompatibility

2014 ◽  
Vol 87 ◽  
pp. 89-100 ◽  
Author(s):  
Sajjad Habibzadeh ◽  
Ling Li ◽  
Dominique Shum-Tim ◽  
Elaine C. Davis ◽  
Sasha Omanovic
2020 ◽  
pp. 2467-2478
Author(s):  
Amaal S. Sadiq ◽  
Entesar O. Al-Tamimi

A series of polymers containing1,2,4-triazole  and tetrazole groups in their main chains were synthesized through several steps. Poly(acryloyl hydrazide) was first prepared and then subjected to a hydrazide reaction with phenyl isothiocyanate to give a 1,2,4-triazole ring (2). This polymer was introduced into a reaction with chloro acetylchloride to yield polymer (3), which was refluxed with sodium azide to give polymer (4). Polymer (5) was synthesized by the reaction of polymer (4) with  acrylonitrile in the presence of NH4Cl as a catalyst. Finally, polymer (6) was synthesized by the electrochemical polymerization of polymer (5) using  316L stainless steel as an anti-corrosion coating. Polymer-coated and uncoated stainless steel was tested for corrosion safety in a solution of 0.1 M HCl, followed by Tafel and Potentiostatic procedures at a temperature of 293 K. Nano materials such as ZnO were applied to the monomer solution at different concentrations to enhance the corrosion resistance of the 316L stainless steel surface. The results showed that the performance values of corrosion protection for the polymer coating were increased with the introduction of the nano materials. Furthermore, 13C-NMR, 1H-NMR, and FTIR were recorded to confirm the structures of the poylmers, while their physical properties were tested using atomic force microscope (AFM) and scanning electron microscope (SEM).


Stainless steel is used widespread in various industries, but it has poor wear resistance. Therefore, this study aims to investigate the wear resistance of enhanced surface of 316L stainless steel by applying the combination of surface treatments that consist of shot blasting followed by paste boronizing. Glass beads with diameter 250 microns and the blasting pressure of 6 bar has been used as the shot material in conducting shot blasting process. Paste boronizing process was conducted at temperature 950°C for 8 hours soaking. Data were collected and analyzed which concentrating on the samples’ microstructure, microhardness and wear evaluation. Shot blasting improves the case depth of boride layers formed after performing paste boronizing by boosting the boron diffusion owing to the grain refinement created by shot blasting. The ultimate combination of shot blasting and paste boronizing parameters enhance the case depth of the smooth and compact boride layers with high boron content. The hardness performance increase 624% compared to untreated 316L stainless steel which also highly improve the wear resistance of the material. In this investigation, these dual processes of surface treatment which are shot blasting and paste boronizing can be applied in fabricating the improved 316L stainless steel for industrial usages.


2017 ◽  
Vol 1142 ◽  
pp. 8-13
Author(s):  
Ahmed Al Mehrzi ◽  
Yong Sun Yi ◽  
Pyung Yeon Cho ◽  
Sara Al Saadi ◽  
Ji Sung Lee ◽  
...  

Water droplets formed by the deliquescence of pre-deposited NaCl on 316L stainless steel were investigated. Different total weights of NaCl particles between 0.0005 g and 0.01 g were deposited on 316L stainless steel surface, which were exposed to an atmospheric condition at 80oC and relative humidity of 80% until NaCl droplets were stabilized. The volume of NaCl droplet was linearly proportional to the total weights of pre-deposited NaCl and consequently the chloride concentration in droplets, ranging from 3 to 6 M, did not depend on the NaCl weights. After exposed to the NaCl droplets at 80oC and relative humidity of 80% over 5, 10, and 15 days, all 316L stainless steel samples suffered from pitting. The Cl- ions in the surface films of samples were measured by ToF SIMS. The pit densities on samples were well correlated with the Cl- intensities in the surface films. These results suggest that the pit initiation under NaCl droplets by deliquescence is caused by the Cl- ions either incorporated into surface films or penetrated through them.


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