ANALYSIS OF THE CHANGE IN ROUGHNESS ON A FACE-MILLED SURFACE MEASURED EVERY 45° DIRECTION TO THE FEED

In this article, we analyze the difference (inhomogeneity) of the roughness values measured on a nonalloy carbon steel surface milled with a parallelogram-shaped (κr = 90°) insert as a function of the the tool movement direction and the relative position of the examining points on the workpiece surface. The characteristic distribution of roughness and the magnitude of the deviations were examined by measuring at selected points along several planes on a surface characterized by the movement conditions of the workpiece and the symmetrically arranged tool perpendicular to the machined surface, which formed double milling marks. The selected points mark the lines with specified inclinations with respect to the feed direction, and their measured values were compared. In these directions, the magnitude of the difference in roughness measures was obtained.

Corrosion protection of mild steel in Hydrochloric acid solutions using expired Hydrocortisone sodium succinate drug

The erosion hindrance of carbon steel in 1M HCl in nearness and nonappearance of terminated Hydrocortisone Sodium Succinate has been examined utilizing mass-loss. Comes about gotten appeared that the restraint productivity expanded with the increment of the concentration of the utilized medicate and diminished with the increment of temperature. The adsorption of this sedate on carbon steel surface takes after Langmuir’s adsorption isotherm. A few thermodynamic parameters were calculated. The motor parameters of erosion of carbon steel in HCl arrangement have been examined. Keywords: Corrosion inhibition; Carbon steel; Hydrocortisone

Experimental and computational chemical studies on the corrosion inhibitive properties of carbonitrile compounds for carbon steel in aqueous solutions

The present work aims to study 6-amino-4-aryl-2-oxo-1-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives namely: 6-Amino-2-oxo-1,4-diphenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-H), 6-Amino-2-oxo-1-phenyl-4-(p-tolyl)-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-Me) and 6-Amino-4-(4-hydroxyphenyl)-2-oxo-1-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-OH) as corrosion inhibitors to provide protection for carbon steel in a molar hydrochloric acid medium. Chemical measurements such as (weight loss) and electrochemical techniques such as (Potentiodynamic polarization, electrochemical impedance spectroscopy, and Electron frequency modulation) were applied to characterize the inhibitory properties of the synthesized derivatives. The adsorption of these derivatives on the carbon steel surface was confirmed by Attenuated Total Refraction Infrared (ATR-IR), Atomic Force Microscope (AFM), and X-ray Photoelectron Spectroscopy (XPS). Our findings revealed that the tested derivatives have corrosion inhibition power, which increased significantly from 75.7 to 91.67% on the addition of KI (PdC-OH:KI = 1:1) to inhibited test solution with PdC-OH derivative at 25 °C. The adsorption process on the metal surface follows the Langmuir adsorption model. XPS analysis showed that the inhibitor layer consists of an iron oxide/hydroxide mixture in which the inhibitor molecules are incorporated. Computational chemical theories such as DFT calculations and Mont Carlo simulation have been performed to correlate the molecular properties of the investigated inhibitors with experimental efficiency. The theoretical speculation by Dmol3 corroborates with the results from the experimental findings.

Interactions in Composite Film Formation of Mefp-1/graphene on Carbon Steel

Mefp-1 adhesive protein derived from marine blue mussels, together with the 2D material graphene, was used to build the green composite film with enhanced anti-corrosion property and mechanical strength. The corrosion inhibition of the composite film, formed by different methods, was evaluated by using electrochemical impedance spectroscopy. The non-degraded adhesion of the composite film to the carbon steel substrate was proved by nano-scratch tests. Infrared spectroscopy was utilized to investigate the film formation process and “three-body interactions” between Mefp-1, graphene and carbon steel surface. The results show that the Mefp-1 adsorbs on the carbon steel surface mainly through the covalent bond between catechols and Fe(III). Meanwhile, Mefp-1 can bond to non-adhesive graphene by forming hydrogen bonds and π−π interaction non-covalent bonds, which facilitate the formation of a robust Mefp-1/graphene composite film on the carbon steel surface.

Characteristics and corrosion protection of polypyrrole doped with salicylate anions on CT3 steel passivated by molydate

In recent years, the conducting polymers have attracted much attention in research and development because of their applications in medical and civil engineering. Here, the salicylate doped polypyrrole films were prepared on the carbon steel surface and their corrosion protection in 3 % NaCl solution were studied. Polypyrrole (Ppy) film was electrochemically synthesised with constant current techniques in a sodium salicylate solution (0.05M, 0.1M, 0.15M) and 0.1M pyrrole monomer on mild CT3 steel electrode passivated by molybdate. The morphological, structural, composition and thermal properties of salicylate doped Ppy films were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) techniques. The anti-corrosion ability of these films was assessed by electrochemical measurements in 3 % NaCl solution. The obtained results suggested that salicylate anions contributed in corrosion protection ability of Ppy films for mild steel electrode. The concentration of sodium salicylate of 0.1M and pyrrole of 0.1M is most suitable for preparation of good protection coating. The self-healing mechanism has been also mentioned for salicylate doped Ppy films on CT3 steel substrate.