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11.
Conclusions  
1.  We established the dependences of the phase composition of high-chromium (18% Cr) steels on the content of nitrogen. As the nitrogen content increases from 0.4 to 1.2% the proportion of untransformed austenite increases and that of martensite decreases respectively. This changes the structural class of the steels from martensitic (at 0.4% N) to austenitic (at 1.2%).
2.  In heating of a quenched steel with 18% Cr and 0.4–1.2% N we determined two temperature ranges of structural transformations that correspond to the segregation of chromium nitrides from the initial martensite (A sA f) and from austenite (B sB f).
3.  With the growth in the chromium concentration from 15 to 24% at 1–1.3% N quenching yields a stable austenite structure preserved even after tempering at 700°C. After heating the quenched steel to a temperature corresponding to the pointB f, the segregation of nitrides from the austenite causes the formation of martensite upon cooling and hence the growth in hardness.
4.  Tempering of steels with an initial structure of martensite or austenite + martensite is accompanied with growth in the hardness due to dispersion hardening of martensite. The hardening is maximum (650–690HV) at a tempering temperature of 500–600°C. The highest level of hardening (649HV) has been observed in steel Kh18A4 quenched from 1200°C and tempered at 600°C.
Translated from Metallovedenie i Termicheskaya Obrabotka metallov, No. 6, pp. 19–24, June, 2000.  相似文献   
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The phase diagram, the glass formation, and the physicochemical properties of glass-forming and crystalline compositions in the Sb2S3-AgI system are investigated. Glasses in this system are moisture-resistant and have high refractive indices. These materials can be used in optical devices operating in the long-wavelength spectral range and as membranes for chemical sensors. The phase diagram of the Sb2S3-AgI system is constructed from the data of X-ray powder diffraction and differential thermal analyses.  相似文献   
14.
Results from tests of the modernized moisture separator-reheaters MSRs-500-1 with Powervane louvers developed by Balcke-Dürr company are presented. Results fromstudies on the determination of wetness of the heated steam at the outlet from the separating part of the MSR and its temperature between super-heating stages, which demonstrate advantages of modernized MSR are discussed.  相似文献   
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The structure of the surface layer in high-nitrogen 05Kh22AG15N8M2F steel workpieces subjected to face turning is studied by electron microscopy. It is found that improved machinability by VK8 alloy cutting tools is achieved at a cutting depth of 0.25 mm and that the cutting-tool life decreases sharply when the cutting depth increases to 1 mm. A nanocrystalline structure with nanocrystal sizes from several to several tens of nanometers forms in the surface layer upon face turning in the as-cast, hot-rolled, and thermally deformed states. The structure of the surface layer is characterized by a high dislocation density and large austenite fragments with broad subgrains and deformation twins.  相似文献   
17.
The structural and phase transformations in high-nitrogen austenitic steel 05Kh20AG10N3MF under various thermal actions are studied. The transformations are shown to occur only in the Fe-Cr diffusion couple, and they resemble the phase transformations in an Fe-20% Cr binary alloy. At 1200°C, hightemperature phase separation is detected; at 550°C or below, low-temperature separation is detected; and at 700 and 800°C, ordering with the formation of a Laves phase is observed. The ordering-low-temperature separation phase transition in the steel differs substantially from that occurring in Fe-Cr binary alloys.  相似文献   
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New glass compositions in the PbO-PbCl2-PbBr2 system are synthesized and the region of vitrification is established. The temperature of sample vitrification is determined using the technique of differential-thermal analysis and the influence of the components on the temperature of vitrification has been studied. Infrared, Raman, and X-ray photoelectronic spectra are registered, suggestions about the glass structure are made, and the X-ray-phase analysis has been carried out. The density is measured and the refractive index of glass is estimated.  相似文献   
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