Increasing the corrosion resistance of low-alloy and carbon steels for automobile construction by optimizing the metallurgical technology

It is shown that the corrosion resistance of automobile sheet can be improved by ensuring that steels of this type have a low content of corrosion-active nonmetallic inclusions (CANI). The main mechanisms responsible for the formation of CANI in automobile sheet have been established, and recommendations have been developed to reduce their concentration in this product • optimize the deoxidation processes that are used by ensuring that the proportions of the additions made to the steel are consistent with the composition of the ladle slag and that certain key temperature-time parameters of these processes are maintained • control the composition of the ladle slag to prevent the formation of solid phases in the slag and their transfer to the metal; certain conditions must also be observed in the argon blow and the introduction of the addtions. Use of the above recommendations to make automobile sheet and tube steels cleaner with respect to their content of CANI and thus help optimize out-of-furnace treatments at metallurgical and pipe plants will make it possible to improve the corrosion resistance of metal products used in automotive manufacturing. __________ Translated from Metallurg, No. 2, pp. 45–48, February, 2006.     

Ethynedithiol‐based polyeneoligosulfides as active cathode materials for lithium‐sulfur batteries

Ethynedithiol‐based polyeneoligosulfides have been synthesized in 96% yield by the reaction of sodium acetylides (HC?CNa, NaC?CSNa) and elemental sulfur through the Na? C_sp bond in liquid ammonia with the following spontaneous polymerization of ethynedithiols (HSC?CSH) formed by the hydrolysis. The polyeneoligosulfides synthesized are brown powders (up to 77% sulfur content, mp 128–184°C), partially soluble in organic solvents. They are high‐resistance semiconductors (10^?13 to 10^?14 S cm^?1), possess paramagnetic (10¹⁷ to 10¹⁸ spin g^?1) and redox properties. The oligosulfides obtained, being redox systems capable of reversible redox processes, provide high values of discharge capacity (345–720 mA h g^?1) of rechargeable lithium‐sulfur batteries. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Prediction of rubber stability by accelerated aging test modeling

This study was devoted to the prediction of polymer material aging. The prediction of the shelf time of tire rubber is used as an example in this article. The main steps of the whole procedure are described. They are the design of the experiment, accelerated aging testing, the construction of a multiresponse mathematical model and parameter estimation, and the extrapolation of the model in real‐life settings. The main pitfalls were deduced, and techniques to overcome these pitfalls are described. Novel methods of data modeling, such as evolutionary design of experiment and successive Bayesian estimation, were used. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1275–1284, 2005     

Silicon as an alloying element in ferrite stainless steels containing 8–13% Cr

A jumpwise improving of the passivation ability and pitting-resistance of the Fe-(8–13)% Cr-(0.32–2.7)% Si alloys upon surpassing the limit of ∼14–15 at % by the chromium and silicon summary concentration is found. It is suggested that the nature of the critical summary concentration C _Cr + C _Si is identical to that in Fe-Cr binary alloys; it is caused by the silicon building-in to the alloy’s crystal lattice and its substitution for chromium in the statistical proportion to its atomic part in alloys. When the summary concentration C _Cr + C _Si approaches ∼14–15 at %, each elementary cell in the Fe bcc lattice must necessarily contain either a Cr atom or the proportional number of Si atoms. The improved passivation ability and pitting-resistance of the Fe-Cr-Si alloy, compared with the Fe-Cr alloys, is explained by the fayalite formation at the alloy surface. Original Russian Text ? I.I. Reformatskaya, I.G. Rodionova, A.N. Podobaev, I.I. Ashcheulova, E.V. Trofimova, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 6, pp. 591–597.     

Phase Composition,Structure, and Hydrolytic Durability of a Uranium-Containing Magnesium Potassium Phosphate Compound

Uranium-containing samples of magnesium potassium phosphate (MPP) compound were synthesized using a nitric acid uranium solution. Uranium is incorporated in the MPP compound in the form of potassium uranyl phosphate with the structure of metaankoleite natural mineral, K(UO₂)PO₄·3H₂O. The differential and integral uranium leach rates, determined in accordance with GOST (State Standard) R 52 126–2003 on the 28th day of contact of the compound with water, are 1.7 × 10^–6 and 2.7 × 10^–6 g cm^–2 day^–1, respectively, and the degree of leaching is 0.014%. High hydrolytic durability of the compound with respect to uranium leaching reduces the risk of release of uranium isotopes from radioactive waste into the environment.     

Increasing the Resistance of Automobile Sheet to Atmospheric Corrosion by Optimizing its Chemical Composition and the Parameters of the Manufacturing Process

A method involving alternating immersion in a 3.5% NaCl solution has been developed for corrosion tests of automobile sheet. Results obtained from 30 cycles of tests (10 + 50 min) of specimens of steels 08Yu, 08ps, 08YuP, 08YuDP, 08GSYuT, and IF established the dependence of the steel's unit weight gain from corrosion products on its combined content of carbon and silicon: steels with a lower content of these elements show a smaller gain in weight, i.e., they exhibit greater corrosion resistance. Steel alloyed with copper (0.23–0.34%) and phosphorus (0.06–0.08%) – the production of which has been mastered by the company Severstal' — has the highest resistance to corrosion. Use of the method makes it possible to rank grades of automobile sheet in one of three corrosion-resistance classifications in relation to their chemical composition and the parameters of the production process. __________ Translated from Metallurg, No. 8, pp. 46–52, August, 2005.