Improvement of the stainless steel electropolishing process by organic additives

The influence of organic additives on the process of surface electropolishing of AISI 304 type steel was determined. Additives were selected in initial potentiodynamic tests pursuant to the plateau analysis on the current/potential curves. The assessment of the operational effectiveness of additives consisted in determining the relationship between surface gloss after electropolishing and the mass loss of the sample and in determining surface roughness. The applied electropolishing bath consisted of a mixture of concentrated acids: H3PO4  and H2SO4 and the following organic additives were used: triethylamine, ethanolamine, diethanolamine, triethanolamine, diethylene glycol monobutyl ether and glycerol. The best electropolishing result, i.e. low roughness and high gloss of stainless steel surface with a relatively low mass loss of the sample at the same time were obtained for baths containing triethanolamine

Surface morphology and passive film composition after pickling and electropolishing

<p>In this work, a novel method of selecting the most favourable electropolishing (EP) conditions is presented as a compromise between the processing time and obtaining the lowest possible roughness value of <i>S</i>_a or <i>S</i>_q (commonly used parameters) as well as the gradual increase of parameters highlighted in this work <i>S</i>_sk and <i>S</i>_ku. The results showed that the most appropriate EP charge input should be higher than 1.2 Amin cm⁻² and lower than 2.3 Amin cm⁻². XPS high-resolution spectra revealed that pickling and EP of the samples results in a decrease of the ratio of the iron oxides amount (at.-%) to the total amount of chromium oxides and hydroxides (at.-%) in the passive film. This ratio gradually decreases reaching the values 1.2, 1.0 and 0.7 for as-received, pickled and electropolished samples, respectively. This result demonstrates iron dissolution of the outer surface layer by pickling and EP.</p

Improvement of the stainless steel electropolishing process by organic additives

The influence of organic additives on the process of surface electropolishing of AISI 304 type steel was determined. Additives were selected in initial potentiodynamic tests pursuant to the plateau analysis on the current/potential curves. The assessment of the operational effectiveness of additives consisted in determining the relationship between surface gloss after electropolishing and the mass loss of the sample and in determining surface roughness. The applied electropolishing bath consisted of a mixture of concentrated acids: H3PO4&nbsp; and H2SO4&nbsp;and the following organic additives were used: triethylamine, ethanolamine, diethanolamine, triethanolamine, diethylene glycol monobutyl ether and glycerol. The best electropolishing result, i.e. low roughness and high gloss of stainless steel surface with a relatively low mass loss of the sample at the same time were obtained for baths containing triethanolamine

Structural Characterization of Carane Derivative Stereoisomers - Potent Local Anesthetics

The paper reports on structural investigation and phase analysis of a newly synthesized potent local anesthetic with chiral molecular structure. Absolute structure and absolute configuration on four chiral centres was determined using microcrystalline single-crystal diffraction with anomalous scattering of X-ray radiation azimuthal scan technique. Phase analysis for new compound (KP23SS) and its epimer (KP23RS) was carried out using classical and synchrotron radiation powder diffraction. Enantiopurity of the bulk material was verified for both isomers by comparison of experimental and simulated high-resolution powder diffraction diagrams. The presence of two new polymorphic phases of KP23RS was documented. Comparative conformational analysis was carried out using differential Fourier synthesis and least-squares molecule overlap technique. A model of epimeric disorder was discussed for the homochiral phase