摘要:
An improved sealing means for use with a slide gate which is slidably mounted for opening and closing movement relative to a seat forming frame defining a fluid flow orifice. The sealing means comprises a resilient sealing member adapted to be received in a groove in the frame, the groove having an outer compartment in which the body of the sealing member is sealed and an inner compartment underlying the outer compartment, the sealing member having an outwardly projecting contoured face adapted to be contacted and displaced laterally inwardly by the gate as it is closed, the lateral displacement of the face of the sealing member causing a rear portion of its body to be displaced into the inner compartment of the groove, thereby accommodating the sealing member to the slide and relieving forces acting to shear the sealing member.
摘要:
In a line for coating a ferrous base metal strip with a molten coating metal, the line being of the type having a preparation furnace for the strip comprising a direct fired furnace, a controlled atmosphere heating furnace, one or more cooling chambers and a snout leading beneath the surface of the molten coating metal bath, all in sealed relationship to each other, the improvement comprising a method and means for maintaining a non-oxidizing atmosphere at positive pressure within the entire preparation furnace during line stop. To this end, a retractable, refractory lined door means is provided in the conduit between the direct fired furnace and its exhaust fan to seal off the direct fired furnace from its exhaust fan and an air dilution opening in that conduit. Additionally, means are provided to add excess nitrogen flow to the preparation furnace to maintain a positive pressure therein. Thus, during a line stop, the refractory lined door will be shifted from its normal retracted position to its position sealing off the direct fired furnace and the means for adding excess nitrogen will be actuated to maintain a positive pressure within the entire strip preparation furnace of the metallic coating line.
摘要:
An austenitic stainless steel which in wrought or cast, and annealed, condition exhibits excellent galling resistance, excellent stress corrosion resistance in chloride-containing environments, good resistance against intergranular corrosion, good high temperature oxidation resistance, and a high work hardening rate. The broad composition range is, in weight percent, about 13% to about 19% chromium, about 13% to about 19% nickel, 0.5% to about 4% manganese, 3.5% to about 7% silicon, up to about 0.15% carbon, less than 0.04% nitrogen, about 0.05% maximum phosphorus, about 0.05% maximum sulfur, and balance essentially iron except for incidental impurities. The steel can be readily worked with conventional equipment and has particular utility for applications in which moving metal-to-metal contact, corrosive attack and/or elevated temperature are encountered in combination. The steel can also be cast into articles of ultimate use, or utilized in power metallurgy techniques.
摘要:
A method of surface treatment of aluminum-killed and low alloy steel strip and sheet for fluxless hot dip metallic coating which comprises heating the steel in a furnace atmosphere containing the hot gaseous combustion products of air with a sulfur bearing gaseous fuel including 5 to 1600 grains of sulfur per 100 cubic feet of fuel wherein the atmosphere includes sulfur compounds and from about 6% free oxygen to about 7% by volume excess combustibles whereby to form a sulfur and oxygen rich film on the steel surfaces, passing the steel into a further heating section wherein it is brought to a maximum temperature of about 593.degree. to about 927.degree. C. in a reducing atmosphere containing at least 10% hydrogen by volume, passing the steel into a cooling section having an atmosphere containing at least 10% hydrogen and the balance nitrogen whereby to reduce the sulfur and oxygen rich film to a metallic iron surface, and cooling the steel approximately to the temperature of the molten coating metal bath. Coke oven gas may be used as the fuel for the furnace.
摘要:
A process of producing non-aging, low carbon steel having substantially no yield point elongation in the annealed condition and freedom from critical grain growth. A molten steel having an analysis typical of steel intended for rimmed or killed drawing steel is vacuum degassed to decarburize to a maximum carbon content of about 0.015%, and columbium (niobium) is added in an amount at least sufficient to combine with the carbon present in the steel. The cast material is hot rolled, finishing at 1500.degree. - 1700.degree. F (about 1090.degree. - 1200.degree. K) and coiled at a temperature of about 1500.degree. F (about 1090.degree. K) or less. The columbium addition retards the rate of recrystallization of the cold rolled product, and a wide spectrum of mechanical properties can be obtained in the final product by control of the final annealing time and temperature within the range of 1000.degree. to 1700.degree. F (about 810.degree. to 1200.degree. K). A preferred product is cold rolled and annealed strip suitable for deep drawing, porcelain enameling, hot dip metallic coating and the like, containing at least about 0.025% uncombined columbium at the hot rolling stage, as determined by analysis at room temperature, which has an average plastic strain ratio of at least 1.8, and a uniform grain size between ASTM 8 and 10.
摘要:
A high temperature continuous strip anneal is added to the routings for both high permeability cube-on-edge oriented silicon steel having a permeability at 796 A/m of more than about 1850 and regular cube-on-edge oriented silicon steel having a permeability at 796 A/m of less than about 1850. For both grades of cube-on-edge oriented silicon steel the high temperature anneal is performed after the decarburization step and before the final high temperature box anneal during which the final desired orientation and magnetic characteristics are achieved. The post decarburization anneal results in improvements in both permeability and core loss.
摘要:
A segmented cylindrical reinforced plastic manhole structure comprising a cylindrical body surmounted by a transition element. The transition element is adapted to support a conventional manhole cover and frame assembly and has an opening closable by the manhole cover. The manhole structure body comprises a plurality of curved, nestable segments of cast or molded reinforced plastic material. Each segment is provided with vertical side edges configured to provide an interlocking joint between it and an adjacent segment and the segments may be so sized as to require two, three or more segments to complete the circumference of the manhole structure body. Each segment is provided with horizontal top and bottom edges configured to provide an interlocking joint between it and an adjacent segment thereabove or therebelow so that the segments may be arranged in tiers to provide a manhole structure body of desired height. The transition element may also be cast or molded of reinforced plastic material and may be segmented or in the form of an integral one-piece structure. A cast reinforced concrete slab-like transition element may also be used. A base member may be provided for the manhole structure body, which base member may also be cast or molded of reinforced plastic material. The segments, transition element and the base member, if used, are joined together by an appropriate adhesive sealant to form fluid-tight joints therebetween.
摘要:
An improved hydraulically driven wire spooler for winding wire on spools at a uniform linear winding speed with means for manually adjusting base winding speed.
摘要:
A method for internal strengthening of articles formed from deep drawing quality low carbon steel strip or sheet containing about 0.02 to about 0.3% titanium in solution, up to about 0.3% columbium in solution, columbium when present being in an amount of at least 0.025% in solution, with the sum total of titanium and columbium in solution not exceeding about 0.3%, comprising the steps of heating the articles at a temperature of about 570.degree. to about 580.degree. C in a nitriding fluid for a time sufficient to form a total nitrogen concentration adjacent the surfaces of the articles at least substantially equal to the amount theoretically required to combine completely with the nitride-forming elements in the steel; and diffusion annealing the articles in a non-nitriding fluid at a temperature of about 595.degree. to about 815.degree. C for a time sufficient to complete through-thickness strengthening by reaction of the nitrogen with the nitride-forming elements. A preferred nitriding fluid is a fused cyanate salt bath.
摘要:
An underwater riser system in which the primary riser is surrounded by lengths of jacket pipe which form annular buoyancy chambers, there being a pressure fluid supply connected to the buoyancy chambers via valve means including at least a pressure differential valve which controls the amount of water displaced from the chamber by the pressure fluid. Advantageously, the valve means for each chamber also includes remotely controlled means by which the amount of buoyancy provided by the chamber can be varied at will, e.g., from a positive buoyancy to a buoyancy less than the operating weight of the portion of the riser system with which that chamber is associated. In best embodiments, the lengths of jacket pipe are interconnected into a continuous structural unit by connectors each having a female connector member secured to the upper end of the lower length of jacket pipe and a male member secured to the lower end of the upper length of jacket pipe, the female member having an annular bulkhead which closes the space between the jacket and primary riser pipe and on which the valve means is mounted.