Showing papers by "Bethlehem Steel published in 1993"

Consolidating Product Sizes to Minimize Inventory Levels for a Multi-Stage Production and Distribution System

Abstract: The optimal design of a supply chain was approached in two phases by using: (1) a mathematical programming formulation and heuristic solution approach to minimize the distinct number of product types held at various points in the supply chain; and (2) a spreadsheet inventory model to estimate the safety stock needed to absorb random fluctuations in both demand and lead time throughout the system. This two-phased approach allowed management to quantify the effects of inventory required for locating parts of the supply chain in different geographic areas. The quantification of projected inventory requirements was a critical input used by senior management to clarify their final decision-making process.

Homogeneous martensitic nucleation in FeCo precipitates formed in a Cu matrix

Abstract: The martensitic transformation on subambient cooling has been monitored in defect-free nanocrystalline f.c.c. FeCo particles that have been coherently precipitated in a Cu matrix; such a CuFeCo system was chosen for study because the f.c.c. → b.c.c. transformational driving force in FeCo alloys is exceptionally large. Transformation is found to occur at a driving force of ∼ 10kJ/mol, a factor of 7 higher than the known critical driving forces for heterogeneous nucleation in bulk alloys. The observed transformation characteristics are entirely consistent with classical homogeneous coherent nucleation, whereas heterogeneous nucleation and homogeneous semicoherent nucleation can be ruled out in this case. An observed variation in transformation temperatures is explained by the experimentally-determined differences in Co content (and, hence, in transformational driving force) among the FeCo precipitates in relation to their distribution of particle sizes. The role of thermal activation in the homogeneous nucleation process is demonstrated by applying a high magnetic field to impose an increment of driving force at low temperatures.

BOF drop-in thermocouple

Abstract: A BOF drop-in sensor assembly includes a handle, a weight, a sensor, and a cage to protect the sensor. The weight includes a high density material having a density of at least 1.2 times the density of steel. The cage comprises crossed rods which are easily melted and which allow molten steel to quickly envelop the sensor providing a highly reliable and accurate reading.

Online tomographic gauging of sheet metal

Abstract: The present invention relates to a computer tomography system which measures the thickness and edge position of hot-rolled steel. X-rays produced by two X-ray sources (10a, 10b) are directed, through the sample (16) being measured, to a plurality of radiation detectors (17). The radiation detectors measure the attenuation of the X-rays caused by the sample (16). The attenuation levels sensed by each detector are correlated with each detector's physical location. This information is collected as each X-ray source (10a, 10b) illuminates the radiation detectors (17). The collected information is triangulated or averaged, as necessary, to determine the dimensions and position of the measured sample (16).

Well block centering tool

Abstract: A centering tool for coaxially aligning a well block with a discharge bore of a steelmaking vessel, the centering tool comprising a support frame and a cluster of pivotable centering arms. Each centering arm includes a wedge shaped portion having a first edge adapted to engage a drive means, and a second edge having a first surface adapted to engage the wall of a bore extending through the well block, and a second surface adapted to engage the wall of the discharge bore of the steelmaking vessel. The drive means includes an expansion plug for engaging and pivoting centering arms positioned within the bore of the well block.

Accelerated Corrosion Test for Aluminum-Zinc Alloy Coatings

Abstract: An electrochemically monitored etching method has been developed to enable accelerated service life testing of aluminum/zinc alloy coatings with a dendritic microstructure. The method invo...

Emerging technologies in the hot-dip coating of automotive sheet steel

Abstract: Customers’ demands for higher-quality hot-dip coated products have led to improved technology for hot-dip coating lines. Because modern hot-dip coating lines operate continuously, the equipment on the line must perform to exacting standards. Current technology in hot-dip lines has transformed the process to the extent that hot-dip products are routinely used for exposed automotive body panel applications. Emerging technologies in hot-dip coating strive to increase the consistency of hot-dip lines and to improve the quality of hot-dip products through a better understanding of the process and implementation of better measurement, control, and production technologies.

Adapting Branch-and-Bound for Real-World Scheduling Problems

Abstract: Many sequencing and scheduling problems can be formulated as 0-1 integer programs and, in theory, solved using a branch-and-bound approach. In practice, real-world instances of these problems are usually solved using heuristics. In this paper we demonstrate the benefits of incorporating an intuitive, user-controlled variable-tolerance into a depth-first branch-and-bound algorithm. The tolerance comprises two components: a variable depth tolerance and a variable breadth tolerance. A sample scheduling problem is thoroughly analysed to illustrate empirically parameter impact on solution quality and execution time. Then, results based on several real-world problems are discussed.

Discussion of “an interpretation of the carbon redistribution process during aging of high-carbon martensite”

Abstract: austenite-to-martensite transformation as a lattice-invariant internal accommodation mechanism. It was argued that these dislocations become resolvable during aging as the result of diffusion of solute carbon atoms to the dislocation cores and the attendant relaxation of the longrange stress fields associated with the dislocations. The Ohmori-Tamura view of the origin of tweedlike structures in aged Fe-C martensites differs fundamentally from that of the present authors. [2,3,4~ We consider the tweedlike images to represent periodic, approximately planar, carbon-concentration modulations which develop by a coherent spinodal decomposition mechanism. Our conclusions are based mainly on results from Fe-Ni-C alloys with subzero Ms temperatures designed to produce virgin ferrous martensites and to permit observation of their aging without prior structural modification that might otherwise arise from the entree of carbon-atom diffusion. While we acknowledge that the presence of nickel may affect the aging behavior as compared with binary Fe-C alloys,* it appears that any such

Nozzle insert for a steelmaking ladle

Abstract: A two piece nozzle insert for use in a steelmaking ladle comprising a nozzle segment and a lock ring segment. The nozzle segment includes a prefired refractory block suited for insertion into the discharge bore of a ladle well block, and the lock ring segment includes a fastening means for removeably attaching the lock ring segment within the discharge bore of a ladle mounting plate. The nozzle segment and lock ring segment include cooperating tapered surfaces to provide a slip plane for compressing and extruding bonding material from between mortar joints of the two piece nozzle insert.

Variable flange beam blank and method of continuous casting

Abstract: A beam blank and a method of continuously casting beam blanks suited for rolling as-cast into an entire range of product sizes within a family of structural products without the need for altering the as-cast geometry in a Breakdown Mill prior to finish rolling.

Consumable lance for oxygen injection and desulfurization and method

Abstract: A consumable lance for simultaneously reheating and desulfurization of a molten metal bath includes an internal circuit for delivering oxygen below the slag metal interface and an external circuit for delivering a desulfurizing agent to the slag metal interface. Improved desulfurization and reheating results are achieved.

High strength, high toughness steel grade and gas cylinder thereof

Abstract: A high strength, high toughness steel comprising from about 0.32 to about 0.36 percent by weight carbon, from about 0.40 to about 0.60 percent by weight manganese, from about 0.15 to about 0.35 percent by weight silicon, from about 0.80 to about 1.10 percent by weight chromium, from about 0.55 to about 0.70 percent by weight molybdenum, from about 0.01 to about 0.05 percent by weight aluminum, from about 0.002 to about 0.004 calcium, no more than about 0.015 percent by weight phosphorus, no more than about 0.008 percent by weight sulfur, with the balance being iron.

Method and apparatus for removing a nozzle insert from a steelmaking ladle

Abstract: A nozzle extraction tool for removing a worn nozzle insert from a steelmaking vessel. The nozzle extraction tool including a support frame, a gripper assembly, and a drive piston for applying a force to the gripper assembly. The gripper assembly includes pivotal gripper arms and a rod assembly for pivoting and rotating the gripper assembly 360° about the longitudinal axis of the worn nozzle insert. The rod assembly enables the gripper arms to be securely seated against the uneven surfaces of the worn discharge bore extending through the nozzle insert.

Method of continuous casting a variable flange beam blank

Abstract: A beam blank and a method of continuously casting beam blanks suited for rolling as-cast into an entire range of product sizes within a family of structural products without the need for altering the as-cast geometry in a Breakdown Mill prior to finish rolling.