Abstract: The invention concerns a ceramically coated dental prosthesis in which the metal frame comprises an alloy containing, each in percent by weight: 0 to 0.4 carbon, 0.1 to 5.0 silicon, 0.01 to 8.0 manganese, 25 to 35 chromium, 1.0 to 8.0 molybdenum, 0.1 to 5 niobium, 0 to 0.3 nickel, 0 to 1.0 iron, the remainder being cobalt and impurities resulting from manufacturing conditions.

Abstract: The method of manufacturing nonmagnetic drilling string components, especially heavy duty drill-stems for exploratory bores, e.g. for deposits of crude oil and/or natural gas deposits, such as directional bores or the like, includes the step of melting and allowing to solidify an alloy consisting essentially of, each in percent by weight:carbon in a maximum of 0.15, preferably 0.08;silicon in a maximum of 1.0;manganese 11.0 to 25.0, preferably 12.0 to 20.0;chromium 10.0 to 20.0, preferably 11.0 to 16.0;molybdenum 0.1 to 1.0, preferably 0.2 to 0.8;nickel 0.1 to 6.0, preferably 1.0 to 3.0;nitrogen 0.05 to 0.5, preferably 0.1 to 0.35; andthe remainder being iron and impurities resulting from manufacturing conditions. The alloy is subjected to an at least two-stage, especially a four- to six-stage hot-working process and, if desired, cooled down and then solution heat-treated at about 1,020.degree. C. to about 1,070.degree. C.

Abstract: The apparatus for excavating passages such as tunnels, shafts and the like, is continually and/or intermittently movable in a predetermined driving direction and contains at least one boring head, possibly, a multipart boring head. In its operative position, the boring head substantially covers the cross-section of the passage to be excavated. The boring head is constructed so as to be thrust or pressed by means of fluid-operated cylinders, tooth racks or the like against the face to be excavated. The apparatus possesses one or a number of drive units for the boring head and at least one device for removing the excavated material. There are further provided a support device for supporting the boring head in the passage and at least one drilling mount possessing a bore motor and a thrust motor for drilling anchor holes and/or blast holes and/or for placing anchors transversely to a predetermined driving direction.

Abstract: A work-hardenable austenitic manganese steel has a base composition (each in percent by weight) of 0.7 to 1.7 carbon, 5.0 to 18.0 manganese, 0 to 3.0 chromium, 0 to 4.0 nickel, 0 to 2.5 molybdenum, 0.1 to 0.9 silicon, up to 0.1 phosphorus and contains micro-alloying elements of 0.0 to 0.20 titanium, 0.0 to 0.05 zirconium and 0.0 to 0.05 vanadium; the remainder being iron and impurities arising from the melting process. The ratio of carbon to manganese is in the range of 1:4 to 1:14 and the total amount of micro-alloying elements is limited to a range of 0.002 to 0.25 percent by weight. The melt of the base composition is tapped at 1,450.degree. C. to 1,600.degree. C. into a casting ladle in which the micro-alloying elements are added. An ingot is cast, cooled, reheated to austenitization temperatures and quenched.

Abstract: A method of fabricating conveyor or feed worms, especially those used in plastic processing machines, containing a tough steel core and a high wear resistant plating. Initially, there is fabricated a compound metal blank by forging or hot rolling a substantially rod-shaped steel core provided with a snugly bearing sleeve or sheath formed of the plating material while forming a metallic bond between the core and the sleeve and while reducing the sleeve diameter by at least 20%. After soft annealing the blank there is formed therefrom the worm profile, and then there is accomplished a thermal treatment which entails hardening and tempering in order to set the hardness of the plating material as well as the core material, and finally there is accomplished the finished machining to the final dimensions.

Abstract: An electroslag remelting furnace includes a liquid-cooled, open-ended mold supported by a bottom plate of high electric conductivity, for instance, formed of copper, which closes the mold at one of its ends. The mold has a plane of symmetry which contains a mold axis. At least one conductor connects at least one terminal located at the bottom plate to a source of electric current. Furthermore, the mold has a normal plane extending normally with respect to the symmetry plane which contains the mold axis. The electric conductor extends from a marginal zone on one side of the bottom plate to the terminal on the other side of the bottom plate beyond the normal plane.

Abstract: A welding additive material substantially free of cobalt and carbide for deposit welding to obtain a welding deposit having high abrasion resistance, high corrosion resistance and high inter-granular corrosion resistance in the non-heat treated state, essentially consists of carbon up to a maximum of 0.15 percent, silicon in the range 3.00 to 10.00 percent, manganese in the range of 3.00 to 12.00 percent, chromium in the range of 22.00 to 30.00 percent and nickel in the range of 7.00 to 16.00 percent, each in percent by weight related to the proportion of the metallic components contained in the core wire and in the coating of a coated rod electrode or the filler of a filler wire of band filler. The remainder may be iron and unavoidable impurities.

Abstract: A method of recovering or extracting chemicals, such as furfural, formic acid, acetic acid and other organic compounds from acidic hydrolysates of plants or vegetable matter, especially spent sulfite liquors after conversion of the pentosans into pentoses and then into furfural by heating the hydrolysate in an acidic environment. The conversion of the pentosans pentoses into furfural, preferably with acidulation, is accomplished in a counterflow or countercurrent flow heat exchanger and a reactor, preferably a tubular reactor. The hydrolysate which has additionally been heated and converted in the reactor is used as a heating medium or heat carrier for heating up the hydrolysate which is converted in the counterflow heat exchanger, whereupon there is recovered as the distillate furfural in conjunction with the formic acid, acetic acid and the like.

Abstract: Consumable electrodes are transferred to and from an operative position in an underlying melting bath by means of a pair of lifts that are vertically movable on masts located on opposite sides of the mold axis. One of the lifts has a fixed portion extending transversely through the axis and toward the other lift, and has a recess aligned with the mold axis and with the path of oscillation of an electrode-transferring arm carried by the other lift. When an electrode is transferred into the recess, a collar on the electrode is clamped to the upper surface of the fixed portion, whereupon the first lift is moved downwardly to position the inserted electrode into the mold. Consumed electrodes are removed by raising the first lift, and engaging a lifting collar on the upper end of the residual portion of the electrode by an arm that is carried for vertical movement and oscillation by the first lift.

Abstract: In a method of producing homogenous ingots of high-melting, nitrogen-containing alloys, whose nitrogen contents are above the solubility limit at atmospheric pressure, according to the electric slag remelting process and using a pressure above atmospheric, a composite electrode consisting of at least one core made of a nitrogen-containing alloy and a jacket made of a nitrogen-containing alloy is used, wherein one of the nitrogen contents is higher and the other one is lower than that of the ingot to be produced.

Abstract: A process and installation for vaporizing liquids and in particular radioactive liquids. A two-step flash vaporization is carried out. The vapor exiting from a first vaporizing stage is condensed by means of liquid taken from a second vaporizing stage, the latter liquid being injected into a condenser into which the vapor steam from the first vaporizing stage is being conducted. The thus formed mixture is conducted into the second vaporizing stage.

Abstract: Distillate produced by the condensing stage of an evaporation installation is conducted to a reservoir to be preheated to its boiling point in preparation for a further degassing step. The required rise in temperature of the distillate in the reservoir is effected by the heat of condensation of a portion of the steam directed via a main pipe from the evaporating stage of the installation to the condensing stage. The required contacting of such steam portion with the reservoir is effected by diverting, to the reservoir, a portion of the steam in the main pipe via a diaphragm or another blocking member interposed in the main pipe and a branch pipe that communicates with the main pipe upstream of the diaphragm member and extends to the reservoir. A conventional overflow pipe disposed at a predetermined height in the reservoir is effective to conduct the heated distillate to the subsequent degassing stage.

Abstract: An improved liquid level regulator is associated with the reservoir of a degassing stage of an evaporation installation wherein a pump connected to the output of such degassing stage is effective to propel the distillate at an ideally constant rate out of the degassing stage to a suitable utilization device. A feedback path is connected between the pressure outlet of the pump and the suction input thereof via a float valve. The float valve communicates with the degassing stage in such a manner that changes in the distillate level of the degasser reservoir effect corresponding changes in the liquid level of the float valve, whereby a constant level of such distillate in the reservoir of the degasser is maintained.

Abstract: An improved technique is described for effecting decarbonization protection for the surfaces of ferrous metals during heat treatment in an oxidation atmosphere. The surface to be protected is coated, prior to the heat treating step, with a paste-like substance preferably formed from a mixture of boron carbide, potassium boron fluoride, borax and an aqueous binder. The resulting protective coating, which may be sprayed on the relevant surface, has a maximum thickness of .1 mm. Such relatively thin coating having the described composition, which in larger thicknesses is useful for boron-hardening of metallic surfaces, is effective to provide the required decarbonization protection without the accompanying disadvantages of excessive boron atom diffusion.

Abstract: An improved arrangement is described for self-controlling the evaporation rate in the first stage of a two-stage expansion type evaporation installation for radio-active liquid purification, as described e.g. in the U.S. patent application Ser. No. 328065 filed on Jan. 30, 1973, in case of failure of the main circulating pump of the second stage. Such failure causes a pressure drop at the mixing condenser between first and second stage and normally, thus, a pressure drop in the first stage too. Such pressure drop leads to unwanted evaporation in the first stage and transfer to the second stage of excessive and insufficiently purified fluid from the first stage. A flow throttle element such as a diaphragm or a necked-down section of steam conduit is interposed between the vapor exit of the first stage and the mixing condenser in which the vapor is condensed by contact with a portion of the liquid from the second stage circulated therethrough by the pump.