Protective Aftereffect of IFKhAN-92 Inhibitor for Corrosion of Nickel–Chromium Steel in Hydrochloric Acid

It is shown that the multimolecular protective layer of an organic inhibitor formed on the surface of chromium–nickel steel in an HCl solution containing a triazole derivative, the inhibitor IFKhAN-92, has a protective aftereffect in background solutions of the same acid. Such a protective layer is chemically bonded to the Fe, Cr, and Ni oxide and hydroxide phase adjacent to the metal phase. The lower part of the polymolecular protective layer of the organic inhibitor consists of a polymer complex formed by IFKhAN-92 molecules, metal cations (Fe, Cr, and Ni), and chloride anions, and the outer part consists of physically adsorbed IFKhAN-92 molecules, which are easily removed from the metal surface during ultrasonic washing of samples.

     

Testing ladle brick made by various factories

Conclusions The resistance of linings in steel-casting ladles depends on the working conditions and the construction of the lining, the quality of the brick laying during repairs of the working layer, and the resistance of the ladle brick. The greatest effect on the wear of the lining in ladles is exerted by the following working conditions: chemical composition of the slag, temperature of the metal being cast, the dwell time of metal and slag in the ladle during one casting, the height of the slag layer in the ladle, the thickness of the lining in each belt of the structure. The quality of the structure in the ladles is mainly determined by the size of the joints, the care with which they are filled with mortar, uniformity of drying and warming-up of the ladles before filling them with metal.The resistance of the ladle brick depends mainly on the apparent porosity and nature of the pores and the concentration of fluxes and mullite in the brick.The highest resistance in service was shown by Zaporozh'e ladle brick made from Polozhe kaolin and having the lowest apparent porosity. The concentration of iron oxides in the brick was moderate, and on average equalled 1.39%.In terms of falling resistance the ladle brick of the remaining concerns can be placed in the following order: Chasov-Yar, Semiluks, Bogdanovich, Magnitogorsk, and Borovich.In order to increase the resistance of steel casting ladle linings it is necessary to increase the resistance of the ladle brick by reducing the apparent porosity, using raw materials with low concentrations of fluxes and improving the firing in order to obtain the maximum conditions of the ladle, reducing to a minimum the quantity of slag and reducing the casting time; to use a more rational thickness for laying the ladles over the courses, taking into account better use of their capacity.Translated from Ogneupory, No.5, pp. 27–32, May, 1970.     

Sonic method for checking the thermal shock resistance of steel-casting plugs

Conclusions A method was developed for determining the thermal-shock resistance of steel casting plugs from the frequency of the mechanical oscillations using the sonic method without breaking the products.The sonic method of checking the properties of the plugs enables us to increase the working reliability of stopper devices during the casting of steel by means of a greater representation of the sample plugs, accelerating the certificating process by a factor of ten, and improving the working conditions.The method has been introduced for checking the properties of samples in enterprises of the refractories and metallurgical industry. The introduction of the method will give a substantial economic saving.Translated from Ogneupory, No. 5, pp.4–10, May, 1972.     

Chamotte and semiacid ladle brick from Barzassk clays

Conclusions The Barzassk (basic O1 and O2, and semiacid PK1) clays are suitable for making chamotte and semiacid ladle brick. The production of refractories from these clays can be organized using the technological production scheme for chamotte articles made by semidry pressing. In order to increase the strength of the green products made from semiacid clays it is necessary to reprocess the bodies with an addition of sulfite lye on runner mixers with rollers.The resistance of the experimental chamotte and semiacid brick in a 300-ton ladle was practically the same as that of ladle brick made from Buskul'sk clay produced by the Magnitogorsk Metallurgical Combine.Translated from Ogneupory, No. 5, pp. 1–5, May, 1969.     

Automatic activity of pacemaker cells in the atrioventricular valves of the rabbit heart

The microelectrode technique applied revealed an automatic activity of the pacemaker cells with slow diastolic depolarization in the cusps of the atrioventricular valves obtained from 34 rabbit hearts. Electrophysiological characteristics of the action potentials of these cells were investigated. Inhibitors of slow sodium-calcium canal (Mn++, Co++, and Mg++ ions) proved to eliminate the automatic activity of the pacemaker cells. When the content of potassium ions was elevated in the perfusion solution, no suppression occurred. It is suggested that the automatic activity of the pacemaker cells in the atrioventricular values depended mainly on the functioning of the slow sodium-calcium canal.     

New Atmospheric Corrosion Inhibitor of D16 Aluminum Alloy

Protection of Metals and Physical Chemistry of Surfaces - Abstract—A mixed corrosion inhibitor (CI), which is an equimolar composition of sodium oleyl sarcosinate (SOS) and sodium...     

A Study of a Novel Nanocomposite Material Based on Reduced Graphene Oxide and Poly(<Emphasis Type="Italic">o</Emphasis>-Phenylenediamine)

The formation of a nanocomposite coating based on reduced graphene oxide (RGO) and poly(o-phenylenediamine) (PPD) in the chemical reaction of graphene oxide (GO) and o-phenylenediamine (OPD) has been studied by cyclic voltammetry (CVA), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). It has been shown that the action of cyclic polarization provides a more uniform structure of the nanocomposite films (decrease in the corrugation effect). In addition, it has been found that the polarization of GO films containing the OPD monomer distributed inside to the PPD synthesis potentials leads to the formation of uniformly distributed globular structures, which most probably correspond to a polymer electrochemically synthesized in the space between the GO nanosheets.