Abstract: The invention relates to a method for producing a ferroalloy containing nickel. From a fine-grained raw material containing iron and chromium and a fine- grained raw material containing nickel, a mixture is formed with binding agent, the mixture is agglomerated so that first formed objects of desired size are obtained. The objects formed are heat treated in order to strengthen the objects so that the heat treated objects withstand conveyance and loading into a smelter furnace. Further, the objects are smelted under reducing circumstances in order to achieve ferrochromenickel, a ferroalloy of a desired composition containing at least iron, chromium and nickel.

Abstract: The invention relates to a duplex stainless steel having austenitic-ferritic microstructure of 35-65% by volume, preferably 40-60% by volume of ferrite and having good weldability, good corrosion resistance and good hot workability. The steel contains 0.005-0.04% by weight carbon, 0.2-0.7% by weight silicon, 2.5-5% by weight manganese, 23-27% by weight chromium, 2.5-5% by weight nickel, 0.5-2.5% by weight molybdenum, 0.2-0.35% by weight nitrogen, 0.1-1.0% by weight copper, optionally less than 1% by weight tungsten, less than 0.0030% by weight one or more elements of the group containing boron and calcium, less than 0.1% by weight cerium, less than 0.04% by weight aluminium, less than 0.010% by weight sulphur and the rest iron with incidental impurities.

Abstract: The invention relates to a method and equipment for controlling flatness of a stainless steel strip in connection with cooling after annealing in a finishing line.

Abstract: The invention relates to a stainless steel product, particularly to a duplex stainless steel casting with high machinability, to the use of the product and to the method to produce the product. The product contains in weight percent up to 0.07% carbon, up to 2% silicon, 3-8% manganese, 19-23% chromium, 0.5-1.7% nickel, up to 1% of molybdenum and/or tungsten with the formula (Mo+½W) less than 1%, up to 1% copper and 0.15-0.30% nitrogen, the remainder being iron and incidental impurities.

Abstract: A method of producing a fluxing agent that can be used in production of steel, preferably stainless steel, employs as a raw material a hydroxide sludge that results from neutralization of metal-contaminated pickling liquid from a pickling step for a steel and contains at least one fluoride-containing compound. The hydroxide sludge is calcined. Steel, preferably stainless steel, is produced by decarburizing a steel heat, whereby a slag is formed on top of the steel heat, and adding a fluxing agent to the slag.

Abstract: The invention relates to a panel structure, in which structure at least two layer sheets (1,6;12,13;22,23;31,32;41,44,45) are fixed to each other with at least one connection member (2,11,21,33,42,43,46) and the connection member (2,11,21,33,42,43,46) is generated from one of the at least two layer sheets (1,6;12,13;22,23;31,32;41,44,45). At least part of the connection member (2,11,21,33,42,43,46) is diverged from the layer sheets (1,6;12,13;22,23; 31,32;41,44,45) forming at least one opening (8,17,27,35) through the layer sheet (1,6;12,13;22,23;31,32;41,44,45) wherefrom the connection (2,11,21,33, 42,43,46) is generated.

Abstract: The invention relates to a martensitic stainless steel to be used for making a razor, surgical and similar blades or other cutting tools, which steel contains 0.40 to 0.55 wt % carbon, 0.8 to 1.5 wt % silicon, 0.7 to 0.85 wt % manganese, 13.0 to 14.0 wt % chromium, 1.0 to 1.5 wt % molybdenum and 0.2 to 0.4 wt % nickel, 0.02 to 0.04 wt % nitrogen, the balance of the steel being iron and inevitable impurities. The invention also relates to a method of manufacturing the said steel.

Abstract: A method of producing a fluxing agent that can be used in production of steel, preferably stainless steel, employs as a raw material a hydroxide sludge that results from neutralization of metal-contaminated pickling liquid from a pickling step for a steel and contains at least one fluoride-containing compound. The hydroxide sludge is calcined. Steel, preferably stainless steel, is produced by decarburizing a steel heat, whereby a slag is formed on top of the steel heat, and adding a fluxing agent to the slag.

Abstract: The invention relates to a method for manufacturing a ductile, high strength austenitic stainless steel object from an austenitic stainless, steel strip, in which method the strip is cold worked in order to promote the formation of martensite into the microstructure of the strip, and the strip having a dual-phase microstructure is further processed. The strip is then shaped to a desired object having at least one curved or arcuate area and during the shaping of the object the different areas of the strip are deformed in different degrees. The desired object is further reversion annealed in order to reverse martensite back to the austenite form and a hardening effect is achieved in order to have an essentially fine grain microstructure for at least the curved or arcuate area of the object.

Abstract: The invention relates to a method for controlling a metal strip to be heat-treated, contained in a continuously operated heat treatment furnace and proceeding in an essentially horizontal direction and suspended position in a zone arranged between elements meant for supporting the metal strip when said metal strip is being cooled. The trajectory of the metal strip is measured by a measuring device, and on the basis of the obtained measurement results, the metal strip is subjected to a controlled cooling agent jet, so that the trajectory of the metal strip, at least in the zone located between the elements meant for supporting the metal strip, is made to proceed in between devices installed around the trajectory and meant for conveying the cooling agent.

Abstract: The invention relates to a method in connection with steel production for handling of hydroxide sludge formed in the neutralization of spent metal-contaminated pickling agents from a pickling step for steel, preferably stainless steel and for using calcium fluoride in the hydroxide sludge to replace the natural fluorspar as a fluxing agent in connection with steel production. Accordingly, the addition of the reactive neutralization medium is monitored by the pH electrodes operated in continuous fashion, and the pH value is adjusted at the range between 9.0 and 9.5.

Abstract: A heat exchanger tube that comprises a tubular member having a longitudinal axis and having an inner surface that is divided into at least two regions along the circumferential direction. A first plurality of polyhedrons are formed on the inner surface along at least one polyhedral axis. Each of the polyhedrons have four opposite sides. The polyhedrons have first and second faces that are disposed parallel to the polyhedral axis and have third and fourth faces disposed oblique to the polyhedral axis. The polyhedral axis is disposed at a first helical angle with respect to the longitudinal axis of the tube. A second plurality of polyhedrons is formed on the inner surface adjacent to the first plurality of polyhedrons. The second plurality of polyhedrons is disposed along at least one polyhedral axis. Each of the polyhedrons has four opposite sides. The polyhedrons have first and second faces disposed parallel to the polyhedral axis and have third and fourth faces disposed oblique to the polyhedral axis.

Abstract: High-alloy austenitic stainless steels that are extra resistant to pitting and crevice corrosion in aggressive, chloride-containing solutions have a tendency for macro-segregation of Mo, at solidification of the melt. This problem is solved by a super austenite stainless steel having the following composition, in % by weight: max 0.03 C, max 0.5 Si, max 6 Mn, 28-30 Cr, 21-24 Ni, 4-6% (Mo+W/2), the content of W being max 0.7, 0.5-1.1 N, max 1.0 Cu, balance iron and impurities at normal contents originating from the production of the steel.

Abstract: A process for producing a solution of a gas in a liquid in which the gas is soluble, the solution having a predetermined concentration up to saturation. The gas and the liquid are brought together under controlled supply in a proportion corresponding to the predetermined concentration of the solution, and the gas and the liquid are caused to form a stream passing through a common conduit. The gas and the liquid in the stream are caused to intermix under the action of gravity, and the intermixing is repeated before the gas and the liquid have separated, so that the gas is substantially absorbed in the liquid, forming a gas-liquid solution of the predetermined concentration. The stream may be brought into turbulence for intensifying the intermixing of the gas and the liquid. An apparatus for performing the process comprises a conduit including a continuous tubular coil formed with a plurality of upwardly and downwardly directed sections.

Abstract: The invention relates to an arrangement (1, 12, 16) for continuously tapping a molten phase, such as matte, from a smelting furnace, such as a flash smelting furnace, said arrangement comprising a matte tapping hole (5) provided in the furnace wall for discharging the molten phase from the furnace, an overflow tank (6) for receiving the molten phase (4), and an overflow edge (8) provided in the overflow tank for discharging the molten phase, so that in the smelting furnace, in the vicinity of the matte tapping hole (5), there can be arranged at least one heat-producing element (9, 15) in order to prevent the molten phase from being solidified.

Abstract: To protect a plate-type heat exchanger (1) against corrosion due to the attack of sulfuric acid, it is proposed in accordance with the invention that the region through which flows sulfuric acid has at least one metal cathode (16, 17) and one reference electrode (27), that at least half the metal plates (7) have an electric contact (23) which is connected with the anode (21) of an electric d.c. voltage source of variable electric voltage, that the metal cathode (16, 17) likewise is electrically connected with the d.c. voltage source, and that the d.c. voltage source belongs to a potentiostat (20) which is electrically connected with the reference electrode (27).

Abstract: The invention relates to an apparatus for rolling a strip (21) comprising a first work roll (24), which is mounted from both ends with bearings (35) to the mill frame, a second work roll (25), which work rolls (24, 25) are forming a nip (26) in between them, one or more ring(s) (19, 20) closing inside at least one of the work rolls (24, 25), at least first intermediate roll (27, 39) mounted to the mill frame from both ends with bearings (36) and arranged in rolling contact between the second work roll (25) and inside surface (22) of the ring(s) (19, 20). The invention also relates to the method of producing a thin strip.

Abstract: This invention relates to a method for the thermal treatment of granular solids in a fluidized bed (3, 3a) which is located in a fluidized-bed reactor (1, 1a), wherein microwave radiation is fed into the fluidized-bed reactor (1, 1a) through at least one wave guide (5), and to a corresponding plant. To improve the efficiency of the microwave irradiation, the irradiation angle of the microwaves is inclined by an angle of 10° to 50°, in particular 10° to 20°, with respect to the principal axis (11) of the fluidized-bed reactor (1, 1a).

Abstract: The invention relates to method for leaching zinc-containing materials in connection with the electrolytic recovery of zinc. According to this method, the feed materials i.e. zinc calcine and zinc sulphide, are leached in three stages, in which he sulphuric acid content of the stages rises in accordance with the direction in which the solids are moving. The solids and solution formed in the leaching stages are routed throughout the process countercurrently in relation to each other.

Abstract: A D.C. voltage altering device includes at least one spark induction power conditioner including a first electrode connectable to a high voltage D.C. power source and a second electrode spaced from the first electrode and forming a discharging gap therebetween. The second electrode is connectable to a predetermined section of a physical separator and at least one of the electrodes is selectively positionable for altering spatial distance between same. The power conditioner induces a predetermined large amplitude, high frequency current ripple to the second electrode for creating a fluctuating voltage and fluctuating electrostatic field and maintaining continuous current flow through the gap without reversal of polarity. The spark induction power conditioner further includes a dielectric base for housing the electrodes and a plurality of fastening members threadably positionable through the base and engageable with the electrodes so that the discharging gap between the electrodes can be selectively adjusted.