Carbon-ceramic composite materials with protective erosion-resistant coatings

Results are presented for the development of production examples of creating refractory materials and structures made from them for the metallurgical industry from carbon and ceramic carbide-forming substances. Practical recommendations are proposed for creating integral structures of new refractory materials for high-temperature processes with a limiting operating temperature of the corresponding carbide protective coatings that exceeds the operating temperatures in air for graphite structural materials. by more than 1000°C. Experimental studies are performed on 16 prepared reactor units for high-temperature chemical processes with an absolute pressure within a reactor of 0.3 MPa and an operating temperature of 900°C. All of the technical specifications for a chemical reactor for air tightness are fulfilled with a reserve of operating capacity. __________ Translated from Novye Ogneupory, No. 2, pp. 47–53, February, 2007.     

Developing methods of controlling the structure and properties of cold-rolled steel to increase usable output and stabilize mechanical characteristics

Recommendations have been developed on optimizing hot rolling in the finishing train of a 2000 mill and subsequent coiling of the rolled product. The goal was to improve the stampability characteristics of steel 08Yu. Specific recommendations were also made on the optimum annealing and temper-rolling regimes to improve the mechanical characteristics of steel 08Yu. The results of studies show that the structure and properties of the cold-rolled product are significantly affected by the conditions of precipitation of different particles of nonmetallic inclusions. It is shown that it would be expedient to analyze the thermodynamics and kinetics of these processes and study the morphology of the particles and the state of the solid solution. Recommendations on chemical composition and process parameters that were developed on the basis of the results of such analysis are now making it possible to consistently obtain steel 08Yu with high properties. __________ Translated from Metallurg, No. 2, pp. 51–59, February, 2007.     

Tailoring of Magnetic Properties of Magnetostatically-Coupled Glass-Covered Magnetic Microwires

We report on tailoring of magnetic properties of Fe- and Co-rich microwires through magnetostatic coupling among them. We studied hysteresis loops of the arrays containing different number of the Co₆₇Fe_3.9Ni_1.5B_11.5Si_14.5M_0.6 and Fe₇₄B₁₃Si₁₁C₂ amorphous microwires. Fe₇₄B₁₃Si₁₁C₂ microwires have rectangular hysteresis loop, while Co₆₇Fe_3.9Ni_1.5B1_1.5Si_14.5M_0.6 with vanishing magnetostriction constant posses inclined hysteresis loop with low coercivity. The presence of neighboring microwire (Fe either Co-based) significantly modifies hysteresis loop of whole microwire array. In a microwire array containing Fe-based microwires, we observed splitting of the initially rectangular hysteresis loop with a number of Barkhausen jumps correlated with number of Fe-rich microwires. In Co?CCo arrays, we observed a change of inclination of overall hysteresis loop, and consequently magnetic anisotropy field under influence of the additional of Co-based microwire. In the case of mixed arrays containing Fe and Co-rich microwires, we were able to obtain irregular hysteresis loops with unusual shape. In this case, considerable increase of harmonics has been observed. Magnetic field amplitude and frequency affect the behavior of all studied arrays. Increasing the amplitude the shape of hysteresis loop of microwire array containing Fe-based microwires transforms from multi-step to single above certain magnetic field amplitude. In the array with Co-based microwires, we observe a change of coercivity. Observed dependences have been attributed by us to the magnetostatic interaction between the microwires with different magnetic domain structure. Together with the conventional method, such as thermal treatment, designing of arrays containing different types of microwires can serve for tailoring of their magnetic properties.     

Key trends in the development of a metallurgical technology to meet the growing steel quality requirements

The recent increase in the requirements for the service properties of steels of certain grades is discussed. The main trends in this field are noted, and examples are given for improving technological processes according to these requirements that ensure a stable chemical composition of steel, a decrease in the content of harmful impurities, and a decrease in the number of “dangerous” nonmetallic inclusions in steel. It is important to create and effectively use through technological schemes and models for the production of steel products that can correct the process of the next processing stage depending on the results of the previous stage.     

Errors in Clamping Thin-Walled Pipe

Russian Engineering Research - The errors arising when thin-walled pipe is clamped in a three-jaw chuck are determined. The wraparound jaws are bored so that their internal diameter is consistent...     

The characteristics of new species of pathogenic microorganisms in the genus Francisella

The comparative study of newly discovered pathogenic bacteria of the genus Francisella was carried out with the use of a complex of microbiological and serological methods. While having great similarity to the causative agent of tularemia, F. novicida, F. novicida-like bacteria and F. philomiragia had lesser growth requirements, some specific morphological and structural features, were capable of fermenting sucrose and exhibited low pathogenicity to experimental animals. The strains under study proved to be virulent with regard to golden hamsters, who were for this reason proposed as an adequate model for the isolation of these bacteria from environmental objects and pathological material obtained from patients. The use of immunoblotting made it possible to find out that all Francisella species had protein antigens, similar to their electrophoretic mobility and serological activity.     

Methods of Evaluating the Corrosion Resistance of Low-Alloy and Carbon Tube Steels under the Service Conditions of Oil and Gas Pipelines

At present, determining the content of corrosion-active nonmetallic inclusions in tube steels is the best way to evaluate these steels' resistance to local corrosion under the service conditions of oil-field tubing in Western Siberia. However, the method needs to be refined or supplemented. Field tests of tube steels are an important means of gauging the corrosion resistance of these materials and pipes when certain conditions are observed. Laboratory corrosion tests should be performed under conditions identical to the corrosion conditions encountered in the field. The rates of the main corrosion processes that take place during the problem-free operation of pipelines may turn out to be significantly higher in the laboratory than in field tests. __________ Translated from Metallurg, No. 5, pp. 44–50, May, 2005.