Bethlehem Steel

About: Bethlehem Steel is a based out in . It is known for research contribution in the topics: Coating & Corrosion. The organization has 1529 authors who have published 1559 publications receiving 19098 citations. The organization is also known as: Bethlehem Steel Corporation.

Crystallography of YBa 2 Cu 3 O 6+ x thin film-substrate interfaces

Abstract: The epitactic nature of the growth of YBa2Cu3O6+x (YBCO) superconducting thin films on ceramic substrates has been studied using high-resolution electron microscopy (HREM) and selected-area diffraction (SAD) of cross-sectional specimens. The films were grown in situ on (001)-oriented MgO and (001)-oriented Y2O3-stabilized cubic ZrO2 (YSZ) single-crystal substrates by electron beam evaporation. Both of these materials have large lattice misfits with respect to YBCO. Different orientation relationships were observed for films grown on the two types of substrates. These orientation relationships are shown to provide the best matching of the oxygen sublattices across the substrate-film interfaces. A crystalline intermediate layer, 6 nm thick, between the YBCO film and YSZ substrate was observed by HREM and shown by EDS to be a Ba-enriched phase, possibly barium zirconate formed by a reaction. In contrast, the YBCO–MgO interface was found to be sharp and free of any intermediate layers.

Effects of Alloying Elements on the Corrosion of Steel in Industrial Atmospheres

Abstract: From 1934 to 1938, Bethlehem Steel Corporation initiated a series of outdoor corrosion tests involving several hundred low-alloy steel compositions. These tests were conducted in the indus...

Carbonitride precipitation in niobium/vanadium microalloyed steels

Abstract: A detailed study of carbonitride precipitation in niobium/vanadium microalloyed steels is presented. A thermodynamic model is developed to predict the austenite/carbonitride equilibrium in the Fe−Nb-V-C-N system, using published solubility data and the Hillert/Staffansson model for stoichiometric phases. The model can be used to estimate equilibrium austenite and carbonitride compositions, and the amounts of each phase, as a function of steel composition and temperature. The model also provides a method to estimate the carbonitride solution temperatures for different steel compositions. Actual carbonitride precipitation behavior in austenite is then examined in two experimental 0.03Nb steels containing 0.05V and 0.20V, respectively. Samples were solution treated, rolled at 954°C (20 pct or 50 pct), held isothermally for times up to 10,000 seconds at 843°C, 954°C, or 1066°C, and brine quenched. The process of carbonitride precipitation in deformed austenite is followed by analytical electron microscopy (AEM) of carbon extraction replicas. Precipitates are observed at prior-austenite grain boundaries, and also within the grains (presumably at substructure introduced by the rolling deformation). Analysis of the grain-boundary and matrix precipitate compositions by AEM indicates that the grain-boundary precipitates are consistently richer in vanadium than the matrix precipitates, although compositional trends with holding time and temperature are similar for the two types of precipitates. The compositions of both the grain-boundary and matrix precipitates are not significantly influenced by the rolling reduction or the holding time at temperature. As predicted by the thermodynamic model, the precipitates become more vanadium-rich as the vanadium level in the steel is increased and as the temperature is reduced. The agreement between the measured and predicted precipitate compositions is quite good for the grain-boundary precipitates, although the matrix precipitates are consistently more niobium-rich than predicted by the model.

A simple technique to generate in-plane forming limit curves and selected applications

Abstract: A simple technique to generate in-plane forming limit curves has been developed. This technique is based on the Marciniak biaxial stretch test using a single punch/die configuration, but the specimen and washer geometries have been modified in order to achieve failure in both drawing and stretching deformation modes. The experimental technique is described, and the advantages of using this inplane method over the conventional out-of-plane dome method are discussed. It is shown that (a) sheet thickness has an intrinsic influence on forming limits that is not related to small bending strain variations with thickness or to deformation in the presence of friction and curvature, (b) plastic anisotropy (\(\bar r\) value) does not substantially affect forming limits, and (c) in-plane forming limits are slightly lower (5 to 6 pct) than out-of-plane forming limits near plane strain; these differences are smaller than previously reported values (12 to 15 pct) in the literature.

Solubility products for titanium-, vanadium-, and niobium-carbide in ferrite

Abstract: Carbide- and nitride-forming elements, such as titanium, vanadium, and niobium, play important roles in the metallurgy of many modern steel products. These elements readily precipitate as stable carbides/nitrides during processing, even when present at relatively small levels. The precipitation of these alloy carbides/nitrides provides a means for controlling strength or hardness, grain size, the level of solute carbon, and other factors that affect properties and performance. Precipitation in austenite during hot deformation has received considerable attention and ''solubility products'' for many compounds have been published and used as alloy/processing development tools. The technologically important alloy nitrides generally exhibit relatively low austenite solubility. Alloy nitride solubilities in ferrite are even lower and, for practical purposes, can often be considered zero. In contrast, some alloy carbides exhibit substantial solubility in ferrite. However, thermochemical or solubility data on carbide/ferrite equilibria are sparse and, as a result, few experimental ferrite solubility relationships are available. A method is described herein for obtaining such a relationship from a known or assumed austenite solubility product using information on the activity coefficients of the solutes of interest. Solubility relationships for titanium-, vanadium-, and niobium-carbide in ferrite are then derived from published austenite solubility products and available thermodynamic informationmore » on binary Fe-Ti, Fe-V, and Fe-Nb solid-solutions.« less