The Ruhrstahl Heraeus (RH) degasser (Figure 1) is the globally preferred equipment to manufacture high quality vacuum treated steel purified to ppm level of C, H, and N. 1-3 Examples of such steel are ultra-low carbon steel (<30 ppm C) for lightweight automobile applications, high carbon manganese steel (<1.5 ppm H 2 , <40 ppm N 2) for crack resistant railway tracks and electrical steel for transformer cores. Faster operation and the ability to perform gas removal, decarburization, desulphurization, and alloy addition with precise composition control makes RH degassers superior to other metallurgical equipment like the vacuum arc degasser. This paper explores refractories for use in a RH degasser which is used to manufacture steel consumed primarily by the automotive industry, one of the world's largest industries in terms of revenue. The automotive steel market is worth US$

This paper deals with the critical aspects of sintering of crystallizable glass+ceramic system, which is a critical part of low‐temperature‐cofired ceramics (LTCC) process. Densification studies clearly revealed the influence of filler's nature especially at lower glass contents (≤70 vol%) and lower sintering temperatures. In this temperature range, marked improvement in density was observed in the order cordierite>fused silica>mullite>alumina. The decisive role played by wetting of glass on filler has been demonstrated using heating microscopy and wetting studies. However, densification was not influenced by the nature of filler at higher glass contents (>70 vol%) and at higher sintering temperatures. This is because in this range of glass content viscous flow of glass dominates the wetting behavior. This paper brings out the salient features responsible for the sintering behavior of anorthite glass+ceramic LTCC composition.

We report successful identification and preparation of a glass composition in the CaO–Al2O3–SiO2 phase diagram with a judicious choice of fluxes that met all dielectric, electrical, and thermal property requirements for low‐temperature cofired ceramic (LTCC) applications. The glass composition sintered at 900°C attains good density (2.45 g/cc) and does not precipitate any crystalline phase. However, when this glass powder is sintered at the same temperature in the presence of 30 vol% cordierite, crystallization of the anorthite phase is observed, which improves the properties of the composite for LTCC application.

Manganese cobalt spinel oxide coatings have been shown to be effective for preventing chromium volatilization from interconnect alloys and associated cathode poisoning in solid oxide fuel cells. A reaction layer consisting of chromium-containing spinel formed due to interaction of the coating with the chromia scale on the alloy surface and increases the overall area specific resistance (ASR) of the system. Reduction in ASR can be accomplished by reducing the thickness and/or increasing the electrical conductivity of the reaction layer, which includes both the high-chromium spinel phase and the chromia scale. This paper reports the effects of transition metal dopants in manganese-cobalt spinel on the reaction products and chromia scale formed on a ferritic stainless steel alloy. Dense single-phase doped spinel ceramics were prepared through process optimization. High temperature diffusion couple experiments with sintered spinel and ferritic stainless steel SS 441 were carried out to understand the spinel-alloy interactions. Doping of the spinel oxide led to a reduction in the thickness of the chromia scale formed on the alloy. The difference in the morphologies and compositions of interaction layers at 800 • C and 900 • C provides insight on the formation and growth mechanism of a high-chromium spinel.

The reduction in the operating temperature of solid oxide fuel cells (SOFC) to 800°C or lower allows for the use of metallic alloys as the interconnect material. The most commonly used alloys are ferritic stainless steels, which have a combination of good oxidation resistance and appropriate coefficient of thermal expansion. However, volatilization of chromium from the chromia scale can lead to degradation in fuel cell performance, so ceramic coatings are applied to the alloy. One of the most promising coating materials is a transition metal spinel oxide, specifically Mn1.5Co1.5O4, which has good electrical conductivity. In this work, reduction of the long-term cell resistance by modifying the composition of Mn1.5Co1.5O4 to reduce the thickness and/or increase the conductivity of the reaction layer formed at high temperatures has been investigated.