Structural condition of martensite in the surface layer of cold rolling rolls

Conclusions The martensitic base of the surface hardened layer is inhomogeneous in phase composition. Despite complicating concepts post-hardening tempering does not cause homogenization of the martensitic phase. Decomposition of the martensite has a heterogeneous character. In the hardened layer and the transition zone together with the low-carbide constituent there is formed a high-carbon one. The presence of high-carbon -martensite may not inpoint of concepts on homogeneous martensite, the degree of tetragonality of which is close to unity, it is difficult to explain the phenomenon of high hardness of rolling mill rolls. Undoubtedly the high-carbon constituent is one of the factors causing an increase in hardness in tempering of type 9KhMF steel. The two martensites manifest themselves differently in rolling. Concepts of the heterogeneous nature of maratensite may be used for improving the service conditions of rolling rolls.Kramatorsk Industrial Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 10–12, February, 1991.     

Effect of Molecular Additives on the Ignition of Methane–Air Mixtures

Combustion, Explosion, and Shock Waves - The ignition of methane–air mixtures with additives of ClF5, ClF3, OF2, and H2O2 (additive content in the mixtures  $$\le$$ 1%) is studied by...     

New Concepts Accounting for Variations in the Formation of Multilayer Fiber Composite Materials

Fibre Chemistry - Changes in the mechanical properties of fibrous composite materials can be largely explained by quantitatively evaluating variations in the formation of their macro- and...     

Internal Stresses, Corrosion and Electrochemical Behavior in Soils, and Stress Corrosion of Pipe Steels

The results of field tests carried out at main gas pipelines (MP) are shown. The distribution of internal stresses along the MP perimeter is obtained. Polarization currents at differently strained pipeline fragments are determined in soils taken at different distances from the failure epicenter. The mechanoelectrochemical effect is shown to be twice greater in failure soils. Its value can serve as a criterion of the stress corrosion probability.     

Isothermal transformation of austenite in 55S2 steel

Metal Science and Heat Treatment -     

Chromized coatings obtained by spontaneously propagating high-temperature synthesis

The discovery in 1967 of the phenomenon of the propagation of the combustion front of powdered high melting chemical elements, which leads to the formation of high melting compounds, marked the beginning of the application of new technologies of hardening the surface of alloys on the basis of spontaneously propagating high-temperature synthesis (SHS). In dependence on the conditions of realizing SHS processes it is possible to obtain diffusion layers in the regime of combustion or thermal self-ignition. The article reviews these methods on the example of chrornizing of carbon steels. The microstructure, phase and chemical composition of the coatings were investigated. The obtained chrornized layers are very heat-resistant and have great microhardness.Moscow Highway Institute. Institute of Structural Macrokinetics, Russian Academy of Sciences, Chernogolovka. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 8–12, March, 1994.     

Perceptually enhanced blind single-channel music source separation by Non-negative Matrix Factorization

We propose a new approach that improves perceptual quality of the separated sources in blind single-channel musical source separation. It uses the advantages of subspace learning based on Non-negative Matrix Factorization (NMF) in which the bases represent the notes. The cost function is formulated in the form of weighted β-divergence by adopting the PEAQ auditory model defined in ITU-R BS.1387 into the source separation. The proposed perceptually weighted factorization scheme is integrated into the Non-negative Matrix Factor 2-D Deconvolution (NMF2D) and Clustered Non-negative Matrix Factorization (CNMF) to overcome the source clustering problem encountered in under-determined source separation. It is shown that the introduced perceptually weighted NMF schemes, named as PW-NMF2D and PW-CNMF, efficiently learn the bases that enable us to apply a simple resynthesis of the musical sources based on the temporal model stored in the encoding matrix. Source separation performance has been reported on musical mixtures where 1–2 dB improvement is achieved in terms of SDR, SIR and SAR compared to the state-of-the-art methods. Performance has also been evaluated by perceptual measures resulting an improvement of 2–5 in OPS, TPS, IPS and APS values.