Efficiently alloyed ultra-cold-resistant steel for containers used to store and transport liquified natural gas

The storage and transport of natural gas in the liquified state (LNG) has become an important issue in connection with the development of new natural-gas fields on the shores of the Barentz Sea in the Artic region. Ferritic nickel-bearing steels 0N6 and 0N9 — which are more efficiently alloyed than austenitic stainless steel 10Kh18N10T — are well-suited for the thick-walled shells of isothermal containers used for LNG storage and transport. These steels have excellent resistance to cold — down to −164°C. The technology developed to make them allows the production of rolled plates that have a thickness of up to 40 mm and meet the requisite standards on mechanical properties and cold resistance. The article examines features of the microstructure of the steels that allow them to resist temperatures down to −164°C. __________ Translated from Metallurg, No. 4, pp. 63–65, April, 2006.     

Measurement of Semifinished-Product Temperature During Shaping Operations Using a Thermal Imaging Method

An experimental method which has been developed makes use of thermal vision to study the temperature of metal during hot shaping. The method also uses a computer to analyze video images and does not require costly equipment. It is suited for noncontact measurement of the surface of heated semifinished products within the range 400– 1600°C. The article reports the results of commercial trials in which the thermal state of semifinished products was examined during radial-shear rolling, forging, the piercing of shells, and the rolling of tubes on a unit equipped with a Pilger mill. __________ Translated from Metallurg, No. 6, pp. 70–72, June, 2005.     

Effects of electrochemical doping of manganese dioxide with copper and lithium on the physicochemical properties

An electrochemical method has been used with fluoride electrolytes to synthesize specimens of manganese dioxide doped with copper and lithium. The compositions, structures, and physicochemical properties have been examined by chemical analysis and x-ray diffraction. It is found that the specimens have highly defective structures. Conclusions are drawn on the scope for using such products as electrode materials in chemical batteries and as catalysts based on manganese dioxide. __________ Translated from Poroshkovaya Metallurgiya, Nos. 3–4(448), pp. 62–66, March–April, 2006.     

Development of sealing compositions with nanostructure iron-based fillers

The possibility of utilizing nanopowders of iron and Fe-Co-Ni produced bu a thermochemical method in the fabrication of sealing composition materials is investigated. It is established that such hermetic sealing composition materials function reliably under extremal conditions and guarantee elevated strength of adhesion to the surface of the metal and high corrosion and temperature stability. __________ Translated from Poroshkaya Metallurgiya, Nos. 3–4(448), pp. 112–117, March–April, 2006.     

Technology for blowing in a blast furnace on ferromanganese

When a blast furnace is planned to be blown in on ferromanganese after a class I overhaul, it is necessary to choose the type of pig iron that is to be obtained in the initial taps. Blow-ins are usually done on foundry iron, with the furnace then being changed over to ferromanganese during a 2–3-day period. A new method has been developed for blowing in blast furnaces on ferromanganese, the method making it possible to quickly (in no more than 1 day) obtain an alloy with an Mn content up to 70–75% by gradually increasing the concentration of this element. __________ Translated from Metallurg, No. 1, pp. 62–63, January, 2006.     

Industrial production of powders of copper alloys by impact atomization of a jet of melt

A plant for use in impact atomization of a jet of a metallic melt by fast turning impact blades is described. Using as an example industrial production of powders of copper alloys at a rate of 2–2.5 t/h, several positive elements of the method of impact atomization are demonstrated including high yield of satisfactory fractions (90–92%) with comparatively low electricity consumption (4–8 W per kilogram of melt), as well as small overall dimensions, simplicity, and low cost of the impact atomization plant. The characteristics of deposited bronze powders are presented. It is demonstrated that application of impact atomization for large-scale production of powders of copper, iron, and nickel alloys as well as special nickel-and copper-based powders in an inert medium is highly promising. __________ Translated from Poroshkovaya Metallurgiya, Nos. 1–2(447), pp. 112–117, January–February, 2006.     

Promising trends in the development of methods of fabricating structural powder materials (survey)

In the new millennium a trend focused on making improvements in existing technologies of powder metallurgy and on the development of new and promising trends in the creation of powder structural materials is observed. The development of the technology of powder metallurgy is intended to improve methods of warm and injection molding, laser and mechanical alloying, and nitration of high-and lowalloy steels. Considerable attention has been paid to the production of structural materials made of intermetallic compounds, materials, the properties of which exhibit functional gradients. There has also been emphasis on creating nanomaterials fabricated by the sol-gel method, mechanical alloying, and powder spraying. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 92–100, May–June, 2006.     

Development and creation of layered materials for tool purposes with a prescribed property gradient

Layered composite materials based on hard alloys grades VK and TK with graded surface properties are studied. The materials are prepared using standard procedures of thermal diffusion impregnation, deposition from the vapor phase, and ion-plasma deposition. In addition dispersion strengthened hard alloys are prepared by processing in Ti plasma between the stages of preliminary and final sintering. __________ Translated from Poroshkovaya Metallurgiya, Nos. 7–8(450), pp. 30–38, July–August, 2006.     

Production of high-strength tubes made of steels of type 15GFB

A unit for making L-class high-strength pump-compressor tubing composed of low-carbon, low-alloy steels of type 15GFB is now being used on the 140 mill in the tube-rolling shop at the Rustavi Metallurgical Plant. The steel 15GFB pump-compressor tubing made by the technology that was developed has the following service properties: σ_y = 630–670 N/mm², σ_u = 730–780 N/mm², δ = 18–22%, ψ = 55–60%, KCU = 1.6–2.2 MJ/m². The percentage of ductile fracture at room temperature is 85–95%. __________ Translated from Metallurg, No. 1, pp. 79–80, January, 2006.     

Thermochemistry of binary alloys of lanthanum with 3d-transition metals

The enthalpy of mixing for liquid binary alloys of lanthanum with 3d-transition metals (Sc, Ti, V, Cr, and Fe) is determined by a calorimetric method within the field of compositions rich in lanthanum. Data for the partial enthalpy of mixing in the La-3d-metal system with infinite dilution demonstrates a complex relationship of a change in it in the series of 3d-metals connected with gradual filling of the 3d-zone due to alloy formation with lanthanum. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 65–71, May–June, 2006.     

Effects of a solid lubricant and technological parameters on the friction, wear, and mechanical properties of a composite based on polytetrafluoroethylene powder

Mathematical experiment planning methods have been applied to the effects of solid molybdenum disulfide lubricant content and those of technological parameters (content of special carbon fiber, preliminary size reduction time, and composite mixing time) on the antifriction and other mechanical properties of composite materials based on polytetrafluoroethylene and carbon fiber. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 21–32, May–June, 2006.     

Thermodynamic properties of scandium-copper compounds

We have determined the Gibbs energy, the enthalpy, and the entropy of formation for the compounds ScCu₄, ScCu₂, and ScCu by measuring the emf of galvanic cells in the temperature range 845–980 K. We compared the experimental results obtained with known literature data. __________ Translated from Poroshkovaya Metallurgiya, Nos. 1–2(447), pp. 87–91, January–February, 2006.     

Phase equilibria and thermodynamics of binary copper systems with 3d-metals. I. The copper-scandium system

Thermodynamic assessment of the Cu-Sc system was carried out using the CALPHAD method. A set of self-consistent model parameters was obtained with the usage of the information about phases equilibria and thermodynamic. Gibbs energy for the liquid phase was assessed within the framework of the model of ideal associated solution. Optimized model parameters make it possible to reproduce satisfactorily the phase diagram and thermodynamic values. Analysis of the relative thermodynamic stability of supercooled melts and competing crystalline phases let us to predict their glass forming ability by rapid quenching from the liquid state. __________ Translated from Poroshkovaya Metallurgiya, Nos. 3–4(448), pp. 43–55, March–April, 2006.     

Structure and high-temperature strength of composite materials based on boron nitride

The structure and physicomechanical properties of composite materials based on boron nitride within which new phases (mullite and sialon) form during hot compaction are studied. It is established that the microstructure of composites is specified by their texture formation caused by the crystal morphology of boron nitride particles and it is almost independent of composite phase composition. It is shown that the main factor that affects strength is porosity. The dependence of strength on porosity is exponential in character. The strength of boron nitride-mullite and boron nitride-sialon composites is 110–140 MPa and at 20–1200°C it is almost unchanged. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 33–39, May–June, 2006.     

Stainless-steel porous-layered and framework fiber-powder composites

Porous layered and framework composites have been made from stainless-steel fibers and powders in the form of sheets. Measurements have been made on the electrical conductivity, elastic modulus, and ultrasound speed as dependent on the porosity, fiber and powder dispersions, and the structural features of the composites. Framework composites are better than layered ones throughout the porosity range, while purely fiber materials are better with porosity less than 60%. __________ Translated from Poroshkovaya Metallurgiya, Nos. 1–2(447), pp. 45–50, January–February, 2006.     

Phase equilibria in the system Al-Rh

Methods of differential thermal analysis, x-ray diffraction, microstructural analysis and electron probe microanalysis are used to study alloys of the Al-Rh system over the whole concentration range. It is established that the phase of equiatomic composition AlRh melts congruently at 2060°C and it has an extended range of homogeneity (45.1–54.2 at.% Rh). The solubility of aluminum in rhodium reaches 9 at.%, decreasing to 6 at.% at 850°C. Coordinates are determined for the eutectic point l ⇆ AlRh + 〈Rh〉 as 70 at.% Rh and 1715°C. The existence of intermediate phases, their crystal structure, and also the method of forming phases in the field of composition rich in aluminum given in publications are confirmed. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 48–56, May–June, 2006.     

Very fine strontium powder for magnetic ceramics

The possibility of preparing very fine strontium ferrite powder with application of preliminary mechanical treatment in a rolling mill is studied. It is established that powder preparation time is shortened by a factor of 2.5–3 and the amount of coarse particles is reduced. The method used for preparing very fine powder makes it possible to control the size of particles and their specific surface. The powder may be used for preparing permanent magnets with a high specific magnetizability (above 32 kJ/m³). __________ Translated from Poroshkovaya Metallurgiya, Nos. 3-4(448), pp. 3–6, March–April, 2006.     

Phase equilibria and thermodynamics of binary copper systems with 3d-metals. II. The copper-vanadium system

Thermodynamic assessment of the Cu-V system was carried out using the CALPHAD method. The excess heat capacity of the liquid phase was taken into account in the model of its excess Gibbs free energy. Excess thermodynamic properties of limiting solid solutions were represented by regular solution models. A self-consistent set of thermodynamic parameters was obtained using data on the mixing enthalpy and information on the phase equilibria. The thermodynamic properties of the phases and the phase diagram along with its metastable extension were calculated using this set of parameters. The thermodynamic model of the system was used in order to predict the composition limits of formation of supersaturated solid solutions prepared by highly nonequilibrium methods of synthesis. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 71–79, May–June, 2006.     

Features of the fine structure of the X-ray CK α emission bands of multiwalled carbon nanotubes

The electronic structure of multiwalled carbon nanotubes of different diameters fabricated with and without the use of catalysts is investigated by means of ultrasoft x-ray spectroscopy. Nanodimensional narrowing of the CK _α bands of nanotubes with lesser diameter is discovered. A dependence of the electronic structure of multiwalled carbon nanotubes on the type of the catalyst applied is established. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 85–91, May–June, 2006.     

Developing and mastering a technology for making steel with a sulfur content no greater than 15 ppm

The converter shop at the Azovstal’ combine has developed and successfully introduced a technology for making steel that contains no more than 15 ppm sulfur. The combine has already produced commercial batches of tube steel with a maximum sulfur content of 6–15 ppm. Reducing carbon content from 0.10–0.12 to 0.07–0.08% and lowering sulfur content from 40–70 ppm to 6–15 ppm have improved the quality of the metal of the slabs and rolled products made by the combine. Among these improvements: a decrease in axial porosity and axial segregation in the slabs, an improvement in the ductility characteristics of the rolled metal, a reduction in the degree of contamination of plate metal by nonmetallic inclusions, and a decrease in the incidence of plate rejection in ultrasonic tests. __________ Translated from Metallurg, No. 3, pp. 46–49, March, 2006.