Double-layer nonswirl nozzles for continuous casting machine pony ladles

Conclusions A method for chamotte nozzles with protection of the bore with a zirconia concentratebase layer has been developed. The life of the nozzles with the protective layer is at least as good as the zirconia-graphite ones. It is desirable to use the double-layer nozzles in place of zirconia and zirconia-graphite nozzles in teeming of various types of steel.The consumption of zirconia concentrate per unit of product is reduced by 10–12 times, which opens prospects of a significant increase in the volume of production of this new form of parts.Translated from Ogneupory, No. 1, pp. 54–56, January, 1986.     

Pore Propagation Directions in P+ Porous Silicon

A comparative study is presented on the pore propagation directions of porous silicon layers (PSL) formed on p⁺-type substrates of different orientations. PSLs were formed on plain (0 0 1) and (1 1 1) silicon wafers as well as on structured (0 0 1) wafers containing facets of various orientations. During anodization, regular pores follow the 0 0 1 direction on the (0 0 1) planes. While on the (1 1 1) planes fewer regular pores develop and seemingly propagate closely to the 1 1 1 direction. These results indicate that the pores propagate perpendicular to the surface i.e. along the field lines when the surface orientation is either (0 0 1) or (1 1 1).When the silicon surface provided (1 1 0) orientation (Chuang, Collins, and Smith, 1989), or its position is in between the (0 0 1) and (1 1 1) planes then the pores do not propagate perpendicular to the surface but along the 0 0 1 direction.All the phenomena exhibited might be explained by presuming that during formation, the pores propagate along the 1 0 0 directions, and that those 1 0 0 directions are preferred which are closely to the field lines. In PSLs formed on (0 0 1) surfaces the field lines and the 0 0 1 crystallographic direction are coincident. However, in the (1 1 1) oriented wafer where three equally probable 1 0 0 directions exist around the field lines, more irregular structure of PSLs will develop.     

Mechanism responsible for the cooling of air heated by a strong shock wave

The problem of the cooling of a spherical volume of air after departure of a shock wave in air of normal density is studied numerically. Based on the results obtained, a conclusion is made that no radiative cooling wave exists in a real atmosphere.Academic Scientific Complex A. V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of Belarus, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 2, pp. 155–158, February, 1994     

Solution of Grinberg and Chekmareva's first integral equation using an asymptotic series in a small parameter that is present

A method is suggested for constructing the terms in an asymptotic series in a small parameter when seeking the position of the phase front y() in the Stefan boundary-value problem of the first kind for a semi-infinite medium that is at the phase transition temperature at the initial moment.St. Petersburg Mining Institute. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 2, pp. 235–237, February, 1994.     

Simulation of thermophysical processes occurring in transition of the surface metal layer of a moving strong-current gas discharge electrode to an amorphous state

We carried out a numerical simulation of the melting and solidification of a surface layer for various metals and heating parameters with account for phase transitions. We determined the conditions enabling the formation of amorphous metallic structures. The conditions were shown to be realized when the heat source was a steady-state strong-current gas-discharge plasma.Notation W ₀ rate of cooling - q heat flux density - t _ef time of thermal effect - a thermal diffusivity of metal - t andx time and space coordinates - T _mel andL melting temperature and latent heat of the melting of metal - s function of the depth of melting - H thermal function (enthalpy) - T temperature - density - c specific heat - , ,B, ,h dimensionless quantities corresponding tot, x, L, T, H - dimensionless parameter having the meaning of the volumetric fraction of the melt - T _max maximum surface temperature - X _mel depth of melting - t ₀ time of surface cooling Insitute of Molecular and Atomic Physics, Academy of Sciences of Belarus, Minsk. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 68, No. 5, pp. 834–839, September–October, 1995.     

Personal computer program for the investigation of crude oils

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 9, pp. 1112, September, 1993.     

Metallo- and fractographic examination of reasons for failure of two-layer thin-walled bellows operating under compressive loading

Conclusions 1. The structure of the metal and the design of the fractured bellows (with the exception of the parameters D, L,a and t, which changed during service) satisfy the requirements of the normalization and technical documents.2. The main reason for failure of the bellows is its long-term service, almost four times higher than the design life.3. Failure is also caused by the presence on the surface of the bellows of technological roughness acting as regions of microcrack nucleations.4. To increase the efficiency of bellows, it is efficient to produce them from pipes/blanks with an electrochemically polished surface.5. The detected HV—running life dependence can be used to evaluate approximately the number of operating cycles of failed bellows and also their permissible service life.6. The design life of the bellows of the 44.5–15–0.18×2 type under this loading system may be increased from 3000 to 5000 cycles.Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 2, No. 2, pp. 125–127, March–April, 1993.     

Mobile unit for enclosing hot solid waste in a metal matrix

Radon Scientific Planning Department, Moscow. Translated from Atomnaya Énergiya, Vol. 74, No. 6, pp. 531-533, June, 1993.