Showing papers by "Bethlehem Steel published in 1970"

The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron

Abstract: A systematic study of carbide and nitride additions on the heterogeneous nucleation behavior of supercooled liquid iron was undertaken. It was found that titanium nitride and titanium carbide were very effective in promoting heterogeneous nucleation. These compounds were followed by silicon carbide, zirconium nitride, zirconium carbide, and tungsten carbide in decreasing order of effectiveness. The degree of potency of the nucleation catalysts is explained on the basis of the disregistry between the lattice parameters of the substrate and the nucleating phase. Through the inclusion of planar terms the Turnbull-Vonnegut “linear” disregistry equation was modified to more accurately describe the crystallographic relationship at the interface during heterogeneous nucleation.

Effect of Transformation Substructure on the Strength and Toughness of Fe-Mn Alloys

Abstract: Phase transformations in Fe−Mn alloys containing up to 9 pct Mn were studied by optical and electron transmission microscopy. Either equiaxed ferrite, massive ferrite, or massive martensite can form on cooling from austenite. The particular type of transformation product formed was found to depend on the alloy content, austenite grain size, and cooling rate. The mechanical properties of all the transformation products were evaluated using tensile and impact testing and are discussed in terms of the observed microstructural features. Yield strength and impact transition temperature were found to be relatively insensitive to manganese content but were strongly influenced by the transformation substructure and grain size of the transformed phase. In martensite it has been shown that the structural unit analogous to grain size in ferrite is the martensite packet size, which in turn is controlled by the prior austenite grain size. The fracture surface of broken impact specimens and the fracture profile were examined by means of electron and optical microscopy techniques. These fractographic observations were correlated with impact test data and microstructural observations of the various transformation products.

Activities in the liquid Fe-Cr-C(sat), Fe-P-C(sat), and Fe-Cr-P systems at 1600°c

Abstract: The problem of relating interaction coefficients applicable to conditions of constant chemical potential of one of the solute elements in a solution to the usual interaction coefficients at infinite dilution is treated. The formal relationships are applied to data on the Fe-Cr-C(sat) system at 1600°C and to results presented earlier on the Fe-P-C(sat) system at 1600°C. An alternative treatment for obtaining interaction coefficients for relatively concentrated solutions by a statistical technique is also presented and applied to data on the Fe-Cr-P system. When applicable, the former is considered to be more reliable.

Microcracking sensitivity in Fe-C plate martensite

Abstract: Metallographic analysis was used to study the effect of carbon content, grain size, quench rate, and retained austenite on microcracking in Fe-C martensites. It was found that microcracking is directly related to an increase in the carbon content of the martensite and that there exists a carbon content which corresponds to both the onset of microcracking and the formation of plate martensite. Retained austenite indirectly affects microcracking in that more complete transformation yields more martensite and consequently more microcracking. Grain size changes from 100 to 1200 μ, introduced by varying the austenitizing temperature from 1800° to 2400°F and varying the time at 2000°F for 15 hr, did not affect microcracking or the amount of retained austenite. Finally, the investigation emphasizes that microcracking is a manifestation of the impingement of martensite plates and is not a function of the stress state introduced by the quenching medium.

Method for recovering fine coal and coal-containing particles in a coal recovery circuit

Abstract: Improved method of treating a fine coal slurry from a coarse coal washing circuit and/or a slurry from a fine coal recovery circuit wherein the slurries are passed to a first frothflotation step to recover a substantial portion of the fine particles of coal therein as a froth product, dewatering the froth product to obtain a cake product containing usable coal and an effluent containing substantially all finely divided coal particles. The effluent is passed to a second series of frothflotation cells wherein the fine particles of coal are removed as a second froth product and substantially clean water is recovered as the tailings product. The second froth product is returned to the recovery circuit wherein the fine particles of coal are recovered. The tailings product may be recycled if desired.

One-probe method and apparatus for detecting, correlating, and classifying defects in test members

Abstract: Nondestructive test apparatus detects both straight and skewed defects in test members such as steel bars and billets having either curved or flat surfaces. Detecting means, including a probe adapted to scan a surface of said member cyclically during relative lengthwise movement therewith, produces electrical signals representative of defects detected in said member. Electrical signals cause defect pulses to be produced and these pulses are coordinated with probe position pulses in electronic circuits which classify the defects according to location, or location in combination with level of defect severity and/or length, in a longitudinally extending section of the test member. A signal correlator may be added to reject noise and false defect pulses as well as to accommodate skewed defects when either or both such situations are encountered. The finally processed defect pulses are utilized, for example, to activate reworkable or rejectable defect markers downstream of the probe over a section of the scanned surface where the defects occurred in said member.

Method of shrinking collars on a shaft

Abstract: Method and apparatus for shrinking a metallic collar onto a shaft, with means provided for applying a coolant to the circumference of the collar while maintaining pressure thereon.

Coal pellet and a method of manufacturing same

Abstract: A coal pellet which is resistant to hydration and has good compressive strength and resistance to impact, containing fine particles of coal, and a coal tar pitch binder having a softening point of about 90* F. to about 190* F. and having a moisture content not greater than 10 percent. The coal pellet is produced by spraying coal tar pitch heated to a temperature of about 300* F. to about 600* F. onto fine particles of coal having a moisture content of about 12 percent to about 30 percent in a mixing vessel, pelletizing the resultant mixture and drying the pellets to the desired moisture content.

Water-cooled apparatus

Abstract: A water-cooled multitubular lance for introducing oxygen or other materials into the interior of a heated chamber. The lance is designed so that the outermost tubular member is free to expand in an axial direction and carries practically no load. The design is applicable to water-cooled burners, probes and other similar devices.

Method of forming seal for multi-wire strand

Abstract: A short length of a multi-wire strand is surrounded with a mold to provide an annular space about said length Said space is filled with a thermosetting plastic sealant and pressure is applied to force said sealant into and along the interstices of said strand During said application of pressure, the strand is circumferentially heated at the ends of said mold to provide a radial temperature gradient across said ends Pressure is applied to said sealant until the ends of the seal are substantially convex

Apparatus and method for removing and/or adding column sections to a column of a marine structure

Abstract: A method and apparatus for removing and/or adding column sections to a column of a marine structure, such as a mobile drilling platform, employs a carriage for supporting a column section slidably mounted on the marine structure platform and jacking means for moving the platform and column relative to each other. When a column section is to be added to the column, the carriage with a column section supported thereon is positioned above the column. The jacking means is then operated to bring the top of the column into contact with the bottom of the carriage supported column section. The column section is then welded to the column and detached from the carriage. When a column section is to be removed from the column, a carriage is positioned above the column. The jacking means is then operated to bring the column within the carriage, and the column is secured to the carriage. A portion of the column is then severed from the column.

Gas pressure regulated atomizer tip for gas/oil burner

Abstract: A BURNER SUITABLE FOR FIRING A GASEOUS FUEL OR A COMBINATION OF A GASEOUS AND A LIQUID FUEL WITH THE GAS BEING USED TO ATOMIZE THE LIQUID FUEL. PRIMARY GAS IS INTRODUCED TANGENTIALLY INTO THE OIL STREAM IN THE THROAT OF A VENTURI NOZZLE DESIGNED TO EXPAND THE MIXTURE. SECONDARY GAS DISCHARGES THROUGH AN OUTER ANNULUS AND IMPINGES ON THE GAS-OIL MIXTURE DISCHARGING FROM THE VENTURI NOZZLE. THE SIZE OF THE ANNULUS FOR ADMITTING THE SECONDARY GAS IS RENDERED ADJUSTABLE BY AUTOMATICALLY MOVING THE OIL ATOMIZING NOZZLE IN AND OUT OF SAID ANNULUS, SO AS TO MAINTAIN CONSTANT GAS PRESSURE IN THE PRIMARY GAS TUBE AT ALL GAS INLET RATES. THE VELOCITY OF THE MIXTURE DISCHARGING FROM THE NOZZLE WILL THEN BE CONSTANT AT ALL GAS FLOW RATES. THE BURNER HAS GIVEN EXCELLENT RESULTS IN ATOMIZING FUEL OIL WITH GAS FLOWS AS LOW AS 17% OF THE TOTAL B.T.U. FIRED AT A HIGH FIRING RATE (30 G.P.H. OIL EQUIVALENT TOTAL FUEL IN THE CASE OF THE BURNER TESTED), AND ALSO WITH 50% GAS AT A LOW FIRING RATE (10 G.P.H. EQUIVALENT TOTAL FUEL).

Influence of cold work and recovery on the strength and toughness of iron

Abstract: In this work some of the structures typical of those found in thermomechanically processed steels were reproduced by cold work, cold work and recovery, and recrystallization treatments of vacuum-melted iron single-crystals and polycrystals. The mechanical properties of the microstructural features such as subgrain formation, texture development, and grain elongation were recorded. It was shown that although the dislocation subboundaries produced on recovery add an increment of strength to that produced by grain boundaries, they are less effective strengtheners than high-angle grain boundaries. Further, the data suggests that yield strength is related not only to subgrain size but also to the angle of misfit of the subgrain boundaries. Although strength increased with subgrain boundary formation, toughness remained constant. Consequently, the introduction of subgrain boundaries offers a means of improving strength while maintaining toughness. The ductile-to-brittle transition temperature of cold-worked as well as cold-worked and recovered polycrystalline iron varied with specimen orientation relative to the direction of deformation. These variations were primarily a function of the anisotropy of grain dimension that is produced by cold deformation. Toughness was not influenced by the preferred orientations produced by the various processing techniques.

Method of controlling the temperature of molten ferrous metal

Abstract: A method of controlling the temperature of molten ferrous metal poured from a bottom pour transfer ladle over an extended period of time. A thick layer of molten slag is placed on the surface of the molten metal to suppress the formation of convection currents in the ladle. A formula provides the relationship between pouring time and the minimum thickness of the molten slag layer required to obtain a substantially constant temperature of the metal discharged from the ladle.

Method of making parallel wire strand

Abstract: A stabilized parallel wire strand is made by drawing a plurality of wires through a forming die from a plurality of rotatable pay-offs each of which is arranged to rotate in a direction opposite to at least one other pay-off while clamping the wires at their leading ends to prevent rotation of the wires about their axes and finally binding the wires together with a resilient binding at intervals along the length of the strand. After binding the strand can be immediately reeled by actively or passively rotating the strand periodically about its longitudinal axis in alternate clockwise and counterclockwise directions as it passes onto a reel.

Reel of alternately rotated parallel-wire strand and method of making

Abstract: A parallel wire strand is made, preferably with the casts of the individual wires matched against each other in opposed relationship to form a ''''balanced'''' strand, and subsequently reeled upon a reel by rotating or allowing the parallel-wire strand to rotate from side to side about its longitudinal axis as it is reeled to provide a conveniently transportable reel of parallel-wire strand with the strand coiled upon the reel with periodic, alternate clockwise and counterclockwise rotation about the longitudinal axis of the strand.

Unstable Flow in Martensite and Ferrite

Abstract: It is proposed that unstable plastic flow of iron alloys containing carbon or nitrogen occurs when (∂ lnν/∂τ*)T becomes negative (v is the average velocity of the dislocations andτ* the effective stress acting upon them) at the maximum in the force-velocity curve deduced from either the Snoek or the Cottrell steady-state drag model In addition, a nucleating event is necessary A model is developed which predicts relationships between the applied stress, the strain rate and the temperature at the onset of unstable flow, and also the activation energy associated with the event Experiments have been carried out on iron-carbon and iron-nickel-carbon alloys covering a range of carbon concentration in solution The alloys were either annealed ferrite or martensite and, thus, the extremes of the range of possible dislocation density were examined Two distinct types of plastic instability were identified: jerky flow, the result of Snoek interaction, and serrated flow due to Cottrell drag All the qualitative and quantitative features of the phenomenon which were examined were found to be in complete accord with the model The average velocity of the dislocations as a function of the temperature at the start of unstable flow has been deduced from the model and an estimate of the density of dislocations moving at the time has been made using measured values of the critical strain rate The strain rate and temperature at which unstable flow disappears were measured as a function of the carbon concentration and the two types of substructure The data show that an explanation based on the assumption that the phenomenon involved is the same as that producing the Koster internal-friction peak is untenable An alternative suggestion, based on the relative stability of a Cottrell cloud and a carbide precipitate, is discussed briefly and qualitatively

Method of protecting ferrous strip in hot-dip processes

Abstract: A METHOD FOR COATING BATCH ANNEALED FERROUS STRIP WITH MOLTEN METAL BY A HOT-DIP PROCESS IN WHICH FLUXING IS ELIMINATED. THE STRIP IS INITIALLY COATED WITH A VERY THIN METALLIC LAYER BY ELECTROPLATING OR VAPOR DEPOSITION AND THEN, AFTER SUITABLE ACTIVATION OF THE SURFACE, PASSED THROUGH A MOLTEN METAL COATING BATH.

Optimum Fatigue Crack Resistance

Abstract: : An evaluation is made of the influence of mechanical properties on fatigue-crack growth rate. Data representing 4340 and modified 4330 steel show that for levels of the stress intensity factor K below about 40 ksi sq root of (in.) mechanical properties have little influence on growth rate. However, at higher K-levels both the product of Young's modulus, yield strength and fracture toughness, and the product of Young's modulus, tensile strength and true strain at fracture seem to be reasonable indices of crack growth resistance. For K-levels above 40 ksi sq root of (in.) minimum fatigue-crack growth rate is provided by tempering 4340 and modified 4330 at temperatures of about 1000 and 1100 F, respectively. (Author)

Oil well pumping unit having traveling stuffing box

Abstract: An efficient long-stroke pumping apparatus for oil wells. This apparatus comprises the combination of a low and relatively inexpensive supporting structure, an upright stroking wheel or sheave mounted thereon and driven near the ground level, and below-ground counterweight and traveling-seal means for actuating a pumping string. Said seal means reciprocate vertically in a polished pipe fixed within the well tubing, and provide protection against corrosive well fluids to the pumping cable actuated by the stroking wheel.

Method of making foam core sandwich panel

Abstract: A method of making a foam core sandwich panel suitable for use in the building industry by spreading two horizontal panels with a polyurethane foamable resin, allowing the resin to expand partially, then bringing the panel sections with their foam faces together sandwich style, to a vertical position and allowing the foam to complete expansion, coalesce and gel in this vertical position.

Magnetic stabilizing means for strip

Abstract: Tapered poles of an electromagnet are positioned adjacent the edges of a magnetic metal strip as it passes from the surface of a coating bath or the like to stabilize the strip against flutter and other lateral stability disturbing influences.

STRESS-CORROSION CRACKING BEHAVIOR OF AN 18% Ni MARAGING STEEL

Abstract: Stress-corrosion cracking of an 18 pct Ni maraging steel in aqueous solutions was studied using precracked cantilever beam specimens. By appropriate heat treatments, six different structures having the same yield strength were obtained. Although significantly different plane strain fracture toughness values (KIc) resulted, it was found that the threshold plane strain stress intensity (KIscc) was the same for all structures.KIscc had the same value in 3 pct NaCl at various pH values, in 1N H2SO4, and in distilled water. Specimens tested in 3 pct NaCl under both anodic and cathodic applied potentials also exhibited this sameKIscc value. Fractographic inspection of the crack surfaces revealed no apparent differences due to changes in solution, pH, or applied potential. The crack path was intergranular in all cases. However, specimens austenitized at 1500°F exhibited crack branching, whereas in specimens austenized at much higher temperatures branching no longer occurred. Aging time and temperature seemed to change only the time to failure. The mechanism most consistent with all observations appears to be hydrogen cracking.

Gas desulfurization process

Abstract: A SELF-CONTAINED PROCESS FOR REMOVING ACID GASES, SUCH AS HYDROGEN SULFIDE, FORM INDUSTRIAL GASES BY ABSORPTIONDESORPTION, WHICH ABSORPTION-DESORPTION INCLUDES SUBJECTING THE INDUSTRIAL GASES TO A VACUUM INDUCED BY A STEAMJET PROCESS AND THEREAFTER REACTING THE DESORBED GASES IN A CLAUS PROCESS TO PRODUCE ELEMENTAL SULFUR. THE ACID GAS-CONTAMINATED STEAM CONDENSATE OBTAINED AS A BYPRODUCT FROM THE STEAM-JET VACUUM PROCESS IS DECONTAMINATED IN A SEPARATE CONDENSATE STRUPPER, AND THE ACID GASES REMOVED FROM THE CONDENSATE ARE REINTRODUCED INTO THE MAIN DESORBED ACID GAS STREAM. THE HEAT PRODUCED FROM THE CLAUS PROCESS IS UTILIZED, BY HEAT EXCHANGE. TO PROVIDE HEAT FOR THE DESORBING OF THE ACID GASES AND THE STRIPPING OF THE ACID GAS-CONTAMINATED CONDENSATE.

The Fe−Ho binary system

Abstract: The Fe−Ho phase diagram was determined on the basis of data obtained by X-ray diffraction, metallographic and differential thermal analysis techniques. Since emphasis was centered in the region where intermetallic compounds predominate, neither the iron nor holmium terminal regions were included in this study. Eutectic reactions were found to occur at 16.5 wt pct Fe and 875° C, 61 wt pct Fe and 1284° C, and 79 wt pct Fe and 1338° C. The congruent melting points of the compounds Ho6Fe23 and Ho2Fe17 were found to be 1332° and 1343° C, respectively. Two other intermetallic compounds were found, HoFe2 and HoFe3, and had peritectic decomposition temperatures of 1288° and 1293° C, respectively.

Instrument lance for basic oxygen steelmaking furnace

Abstract: An instrument lance for introducing expendable immersion thermocouple devices into a molten steel bath contained in a basic oxygen steelmaking furnace. The instrument lance has means to introduce an inert gas and a fire retardant liquid against the outer surface of the thermocouple devices in order to prevent premature failure of the thermocouple elements as a result of the high temperature present in the heated interior of the basic oxygen steelmaking furnace.

Deformed wire for concrete reinforcement

Abstract: A wire having overlapping rows of indentations in the surface thereof whereby deformation roll wear and/or improper roll adjustment are visually indicated by the deviations from the desired amount of overlap.