Scrap metal: The problem of its shortage and efficient use

The most important element of manufacturing processes that employ new metallurgical technologies is improving the quality of the scrap metal used in the given process. Introducing modern scrap-processing equipment is especially important in this regard. At the same time, it is also necessary to use the latest technological advances in order to reduce the oxidation loss of iron during refining in arc steelmaking furnaces.     

New technological solutions to protect the lining of blast-furnace hearths

The use of schungite as a partial replacement for coke is practiced in Russia at a number of metallurgical plants, both in the production of foundry iron (its primary use) and in making conversion pig iron. The largest amount of coke is replaced when foundry iron is being made, the replacement coefficient in this case having a value within the range 0.8–1.3. Studies that included continuous monitoring of the temperature of the carbon blocks in blast furnaces with volumes of 1719, 3200, and 5580 m³ unambiguously demonstrate that the thickness of the slag crust in blast furnaces increases with the use of schungite. Protecting the lining of the hearth through the use of schungite is also accompanied by a decrease in coke consumption. __________ Translated from Metallurg, No. 8, pp. 53–57, August, 2007.     

Corrosion resistance of a bent plate from a high-nitrogen nonmagnetic 05Kh22AG15N8M2F steel in aggressive media

The corrosion resistance of the convex and concave sides of bent plates from a high-nitrogen non-magnetic steel has been studied in aqueous solutions of sulfuric and hydrochloric acids. Weighing and hydrogen methods are used to control the corrosion rate of bent-sample sides and to find a number of effects that complement the picture of the stress corrosion of iron alloys and support the existence of the mechanochemical deformation sign effect.     

Simulation of contact stresses and forces during hot rolling of thin wide strips with allowance for a stick zone and elastic regions in the deformation zone

A new procedure for the calculation of contact stresses and hot-rolling forces for wide strips 0.8–1.5 mm thick has been developed and tested. This procedure takes into account the presence of a stick zone in the deformation zone and stress distributions in both elastic and plastic regions in the deformation zone. The average error in the force calculation according to the new procedure is 5%, which is more than two times smaller than the calculation error of well-known force calculation procedures. The developed procedure is used to simulate the contact stresses in the deformation zones of working stands in a six-stand 1700 mill during rolling of strips thinner than 1.0 mm. A number of new relations for the state of stress in a strip have been revealed upon simulation. Some of these relations are as follows: in the last stands, the length of elastic regions accounts for 10–17% of the total deformation-zone length; the maximum normal contact stresses are 1300–1400 MPa, which corresponds to the stresses in the deformation zones of cold-rolling mills; the stick-zone length accounts for 85–99% of the deformation-zone length; and the contact stresses in the stick zone are virtually independent of the friction coefficient. The developed calculation procedure can be used to optimize the technological regimes of wide-strip mills.     

Organ distribution of bovine serum albumin administered intragastrically in the rat

Radioimmunoassay was employed to examine distribution of antigenic structures of bovine serum albumin (BSA), absorbed by the gastrointestinal tract, in the blood serum and organs of intact rats. It was shown that 3 h after administering 3H-BSA an appreciable amount of its antigenic structures could be identified in the blood serum, liver, spleen, and carcass of the animals. The total amount of antigenic determinants of BSA which got into the internal environment of the body from the intestine amounted to about 0.2% of the dose administered. The highest specific content of antigenic structures of BSA supplied via the intestinal barrier was detected in the spleen.     

Oxidative stability of the lipids in whitefish

The manometric technique was employed to study the initiated oxidation of 7 samples of whitefish lipids of varying sites, to measure the kinetic parameters depending on the fatty acid composition and concentration of tocopherol. Changes in oxidative stability of lipids of varying localization was shown, a higher stability of muscle tissue lipids was noted as compared with brain and depot lipids. The possibility of testing oxidative stability of lipids according to the kinetic parameters is discussed.