[en] The solubility of carbon in liquid lithium containing < 50 wppm nitrogen has been measured in the temperature range from 220 to 735⁰C and compared with the solubility in lithium containing proportional 2600 wppm nitrogen in that same temperature range. A direct sampling method was employed in which filtered samples of the saturated solution were taken at randomly selected temperatures. The entire sample was analyzed for carbon by the acetylene evolution method. The analytical method was examined critically and it was found that (1) all of the carbon in solution, including carbon introduced as lithium cyanamide is detected and (2) ethylene and ethane must also be measured and included with the acetylene to get complete recovery of the carbon content of the sample. The solubility of carbon in low-nitrogen lithium can be expressed by the equations ln S=6.731-8617T^-1 and log Ssup(*)=7.459-3740T^-1, where S is the mole percent Li₂C₂ and Ssup(*) is in weight parts per million carbon. The presence of proportional 2600 wppm nitrogen does not affect the solubility of carbon in lithium at temperatures above proportional 350⁰C, but at lower temperatures it increased the solubility by as much as an order of magnitude compared to the solubility in low-nitrogen lithium. (orig.)

[en] The grain boundary and triple junction hardenings in molybdenum with different carbon content were studied in connection with the character and the connectivity of grain boundaries at triple junctions by the micro-indentation test. The triple junction hardening is smaller at the junctions composed of low-angle and Σ boundaries than at the junctions composed of random boundaries. This difference in the hardening depending on the grain boundary connectivity becomes more significant with a decrease in carbon content in molybdenum

[en] This review is basically aimed towards the discussion of precipitation effects in austenitic stainless steels, which play such a crucial role in the mechanical and corrosion properties of these materials. As a build up to this subject, fundamentals of the microstructure of steels are introduced and a beginning is made from the iron-carbon system. Various transformations typical of plain carbon steels, and the martensitic and bainitic reactions, are briefly examined but the details of heat treatments are not considered. The effect of the addition of alloying elements, in general, and of chromium and nickel, in particular, to the iron-carbon system is summarized. The Fe-Cr-Ni-C system, which forms the basis of austenitic stainless steels, is described at length. A survey is presented of the formation of carbides, nitrides and intermetallic phases, and its implication, in these steels, Due to its importance, the characteristics of M/sub/23C/sub/6 type precipitation are discussed in detail. (author)

[en] A carbon steel/Cr-cast iron bimetal produced by an alloy cored wire welding method showed a zigzag type fracture in the interface in tension tests. Results obtained from the interface were; ^σUTS=29.75(Kg/mm²) σ_ys=20.08(Kg/mm²) E=8.5 x 10⁷(psi). The evaluated value of J_IC was 0.7 Kg.f/mm. Brittle fracture were observed only in the cast structure. Wear resistance of hardfaced metal was superior to that of base metal. The wear mechanism was mostly abrasive wear,but oxidation wear and adhesive wear were also activated partly. (Author)

No abstract available

[en] It is generally agreed that the difficult step in the formation of isothermal as well as athermal martensite is the nucleation since the growth occurs at a high speed. Previously the difference between M_s and M_g, the temperature below which martensite can grow if it is already nucleated, was determined for an Fe-1.62%C alloy. The difference was surprisingly small indicating that the difference in driving force for nucleation and growth is small. This experimental result is here compared with results on both athermal and isothermal martensite. A discussion about the critical step for the formation of lath and plate martensite formed by rapid continuous cooling is also given. (orig.)

No abstract available

[en] The intergranular corrosion of Ni base alloys (Inconel 600) increase with their C content due to the interaction of this element with the defects of the grain boundaries. In contrast, the intergranular corrosion of Inconel 600 is not modified by an addition of 0.9%Si. This is due to the very high anodic dissolution speed of these alloys containing 16%Cr

[en] Magnesium diboride bulk pellets were fabricated from pre-reacted MgB₂ powder ball milled with different amounts of exposure to air. Evidence of increased electron scattering including increased resistivity, depressed T_c, and enhanced H_c2 of the milled and heat treated sample was observed as a result of increased contact with air. These and other data were consistent with alloying with carbon as a result of exposure to air. A less clear trend of decreased connectivity associated with air exposure was also observed. In making the case that exposure to air should be considered a doping process, these results may explain the wide variability of 'undoped' MgB₂ properties extant in the literature

[en] Boron carbide powders, with and without sintering aids, were sintered in vacuum at 1800-2350⁰C. Sintering behavior was studied as a function of time, temperature and free carbon concentration. The role of additives is discussed in terms of plausible mechanics. Microstructure development and oxidation behavior were also evaluated