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Pittsburgh, PA, United States

The United States Steel Corporation , more commonly known as U.S. Steel, is an American integrated steel producer with major production operations in the United States, Canada, and Central Europe. The company was the world's 13th largest steel producer in 2010. It was renamed USX Corporation in 1986 and back to United States Steel Corporation in 2001 when the shareholders of USX spun off the oil & gas business of Marathon Oil and the steel business of U. S. Steel to shareholders. In 2001 it was still the largest domestically owned integrated steel producer in the United States, although it produced only slightly more steel than it did in 1902, after significant downsizing in the 1980s.U.S. Steel is a former Dow Jones Industrial Average component, listed from April 1, 1901 to May 3, 1991. It was removed under its USX Corporation name with Navistar International and Primerica. An original member of the S&P 500 since 1957, U.S. Steel was removed from that index on July 2, 2014, due to declining market capitalization. Wikipedia.

Chen G.,United States Steel Corporation
SAE International Journal of Materials and Manufacturing | Year: 2010

In August 2005, National Highway Traffic Safety Administration (NHTSA) proposed to increase the roof strength requirement under Federal Motor Vehicle Safety Standard (FMVSS) 216 from 1.5 to 2.5 times unloaded vehicle weight (UVW). To meet the new requirement with a minimum impact on vehicle weight and cost, the automotive community is working actively to develop improved roof architectures using advanced high strength steels (AHSS) and other lightweight materials such as structural foam. The objective of this study is to develop an optimized steel-only solution with low material and part-manufacturing costs. Since the new regulation will present a particular challenge to the roof architectures of large vans, pickup trucks and SUVs due to their large mass and size, a validated roof crush model on a B-Pillar-less light truck is utilized in this study. Optimized steel-only solutions are investigated with the application of CAE optimization technology and AHSS including dual phase (DP) steels up to 980 MPa tensile strength and boron steel for hot stamped parts. HyperStudy® optimization software and LS-DYNA® nonlinear finite element software are utilized together to search for the optimal design. Steel inserts are designed and added at critical locations to improve the load-carrying capacity. Material and gauge optimizations are also performed on key roof components to minimize the vehicle weight while meeting the enhanced roof crush load requirement. The optimized steel-only solutions are compared to the alternative designs using nylon inserts. © 2010 SAE International. Source

De Moor E.,Colorado School of Mines | Matlock D.K.,Colorado School of Mines | Speera J.G.,Colorado School of Mines | Merwin M.J.,United States Steel Corporation
Scripta Materialia | Year: 2011

A model is proposed to predict austenite stabilization through manganese partitioning between ferrite and austenite. The model predicts retained austenite fractions as a function of intercritical annealing temperature based on equilibrium phase fractions and solute contents. Thermodynamic data are used to calculate the Ms temperature of the enriched austenite in order to predict fresh martensite formation upon cooling to room temperature. An intercritical annealing temperature resulting in the greatest retained austenite fraction is predicted which correlates to some experimental observations. © 2010 Acta Materialia Inc. Source

Tumuluru M.,United States Steel Corporation
Welding Journal (Miami, Fla) | Year: 2010

Dual-phase and transformation-induced plasticity (TRIP) steels are finding increased application worldwide in car and truck bodies due to the many advantages they offer. These structures are typically joined by the resistance spot welding process. Subsequently, the welded car bodies and frames are painted and undergo an elevated-temperature paint baking process. Because the effect of baking treatments on weld microstructures and mechanical properties was not known, a systematic study was undertaken to evaluate the effect of paint baking on the tensile-shear strength and microstructure of resistance spot welds in 780 MPa dual-phase and TRIP steels. Peel tests, shear-tension tests, and microhardness traverses were conducted on the as-welded (nonbaked) and baked weld samples. Both as-welded and baked welds were examined using both a scanning (SEM) and a transmission (TEM) electron microscope. The results showed that postweld baking increased the load-bearing ability of the welds in shear-tension tests compared with that of the samples in the as-welded condition. However, for both steel grades, baking had no effect on the fracture appearance in shear-tension tests, as expected, and no noticeable changes were observed in weld hardness. TEM examination revealed that, in both the TRIP and the dual-phase steels, the dislocation density in the ferrite and on ferrite grain boundaries was low in the base or matrix material, but much higher in the heat-affected zone (HAZ) and the weld fusion zone, and large areas of lath and twin martensite were found, along with ferrite, in the weld. Epsilon (e) carbide precipitates were found in twin martensite regions of the weld and HAZ regions in both the dual-phase and the TRIP steels after baking. It is believed that baking introduced Cottrell atmospheres around dislocations and grain boundaries, and thus changed the local yielding behavior, which was manifested in the small increase in shear-tension strength. Further, the low-temperature tempering from the baking treatment caused precipitation of transition (e) carbides in the martensite within the weld and the HAZ, and is believed to have resulted in a certain amount of toughening within these microstructures. Source

United States Steel Corporation | Date: 2011-12-09

A fuel injection lance for an ore-smelting furnace includes a central conduit, a first conduit and a second conduit. The first and second conduits are concentric with the central conduit. A central conduit is connected to a fuel mixture. The first and second conduits are in flow communication with a gas source. The first and second conduits have gas flowing at independently controllable gas flow rates relative to the other conduit. A swirl portion has a cylindrical body with a hollow interior cylinder, and vertical and helical channels formed within the body portion. Vertical channels traverse the body portion vertically to the outer surface adjacent to the bottom surface. Helical channels traverse the outer surface in a helical pattern. Vertical channels intersect with corresponding helical channels at a predetermined angle selected to provide a desired particle distribution of a fuel injected into the furnace.

United States Steel Corporation | Date: 2010-07-27

A contact seal to prevent contamination from fouling a conveyor idler roll, the roll generally comprising a rotatable cylinder, at least one internal bearing assembly, and a fixed axle. A disc of thermoplastic polymer or similarly resilient material is adhesively attached preferentially to an outboard end cap of the idler roll to seal out contamination. A circular aperture through the disc allows the attached seal to rotate about the idler axle. At least one ring of felt or other porous material is adhesively attached to the disc circumferentially to the aperture to filter out contamination when the ring is in frictional contact with the roll end cap. The seal is preferentially divided along the longitudinal axis of the disc to form two interlocking semicircular half-pieces that are snapped together circumferentially about the idler axle so that no disassembly or modification of the idler is required to adhesively attach the seal.

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