Patents Assigned to Hoganas AB
-
Patent number: 6419877Abstract: The invention concerns a process for the preparation of a compressed soft magnetic powder core comprising the steps of compacting an iron based powder the particles of which are insulated by a chromium containing layer, at a pressure between 300 and 1500 Mpa. The compacted body is then heated to a temperature sufficient for achieving stress relief and recrystallization of the iron base material.Type: GrantFiled: March 12, 2001Date of Patent: July 16, 2002Assignee: Höganäs ABInventors: Cecilia Elgelid, Anne Larsson-Westberg, Lars-Åke Larsson
-
Patent number: 6413919Abstract: The invention concerns a process for the preparation of a lubricant combination including to steps of selecting a first and a second lubricant; mixing the lubricants and subjecting the mixture to conditions for adhering the particles of the second lubricant to the particles of the first lubricant in order to form a lubricant combination of aggregate particles having a core of the first lubricant, the surface of the core being coated with particles of the second lubricant. The invention also concerns a surface modified lubricant combination including a core of a first lubricant, the surface of which is coated with particles of a second lubricant.Type: GrantFiled: January 26, 2001Date of Patent: July 2, 2002Assignee: Höganäs ABInventor: Hilmar Vidarsson
-
Patent number: 6395688Abstract: The invention concerns a process for the preparation of a lubricant composite for powder metallurgy including the steps of selecting a first lubricant having a melting point above 120° C. and a second lubricant having a melting point below 110° C.; mixing the lubricants at an elevated temperature in order to melt the lubricants and subjecting the mixture to rapid for providing a lubricant composite including a metastable phase. The invention also concerns the obtained lubricant composite.Type: GrantFiled: January 25, 2001Date of Patent: May 28, 2002Assignee: Höganäs ABInventor: Hilmar Vidarsson
-
Patent number: 6375709Abstract: This invention concerns a lubricant for warm compaction of iron-based metallurgical powder compositions. 50 to 100% by weight of the lubricant is a polyester, aromatic or partly aromatic, which has a number-average molecular weight Mn of 5,000-50,000. This invention further concerns a metal powder composition containing the lubricant, a method for making sintered products by using the lubricant, and use of the same in warm compaction of metallurgical powders.Type: GrantFiled: March 23, 2000Date of Patent: April 23, 2002Assignee: Höganäs ABInventors: Helge Storström, Hilmar Vidarsson
-
Patent number: 6365095Abstract: The present invention concerns a process of preparing high density, warm compacted bodies of a stainless steel powder comprising the steps of providing a mixture of a low carbon, low oxygen stainless steel powder including 10-30% by weight of Cr, optional alloying elements and graphite and inevitable impurities, mixing the powder with a high temperature lubricant and compacting the mixture at an elevated temperature. The invention also concerns a composition of the stainless steel powder, optional additional alloying elements and a high temperature lubricant.Type: GrantFiled: January 24, 2001Date of Patent: April 2, 2002Assignee: Höganäs ABInventor: Anders Bergkvist
-
Patent number: 6355087Abstract: The invention concerns a low pressure for the preparation of an iron-based, optionally alloyed powder comprising the steps of preparing a raw powder essentially consisting of iron and optionally at least one alloying element selected from the group consisting of chromium, manganese, copper, nickel, vanadium, niobium, boron, silicon, molybdenum and tungsten; charging a gas tight furnace with the powder in an essentially inert gas atmosphere and closing the furnace; increasing the furnace temperature; monitoring the increase of the formation of CO gas and evacuating gas from the furnace when a significant increase of the CO formation is observed and cooling the powder when the increase of the formation of CO gas diminishes.Type: GrantFiled: July 18, 2000Date of Patent: March 12, 2002Assignee: Höganäs ABInventors: Johan Arvidsson, Ola Eriksson
-
Patent number: 6348265Abstract: The invention concerns a novel low oxygen powder comprising particles of a base powder consisting of essentially pure iron having an insulating oxygen- and phosphorus-containing barrier. The oxygen content of the new powder is at most 0.2% by weight higher than the oxygen content of the base powder, and the ratio O:P is between 30 and 1, preferably between 15 and 2 and most preferably between 10 and 3 as measured by the ESCA method. The invention also concerns a new method of preparing an iron-based powder comprising the steps of preparing a base powder consisting of a water atomized iron powder or a sponge iron powder, subjecting the mixture to treatment with a solution of phosphoric acid in an organic solvent and drying the obtained mixture, whereby the solution of phosphoric acid is sprayed on the base powder while being mixed.Type: GrantFiled: August 21, 1998Date of Patent: February 19, 2002Assignee: Höganäs ABInventors: Patricia Jansson, Lars-Åke Larsson
-
Patent number: 6348080Abstract: The present invention concerns a method of preparing a sintered product having a tensile strength 750 MPa comprising the steps of compacting a water-atomised, annealed iron-based powder comprising, by weight %, Cr 2.5-3.5, Mo 0.3-0.7, Mn 0.09-0.3, O <0.2, C<0.01 the balance being iron and, an amount of not more than 1%, inevitable impurities, at a pressure of at least 600 MPa and subjecting the compacted body to sintering at a temperature of at most 1220° C. The invention also concerns the annealed powder used in the method as well as the sintered products.Type: GrantFiled: July 18, 2000Date of Patent: February 19, 2002Assignee: Höganäs ABInventors: Johan Arvidsson, Ola Eriksson
-
Patent number: 6342087Abstract: The invention concerns a process for producing low oxygen, essentially carbon free stainless steel powder, which comprises the steps of preparing molten steel which in addition to iron contains carbon and at least 10% of chromium, adjusting the carbon content of the melt to a value which is decided by the expected oxygen content after water atomising; water-atomising the melt and annealing the as-atomised powder at a temperature of at least 1120° C. in a reducing atmosphere containing controlled amounts of water. The invention also concerns a water-atomised powder including 10% by weight of chromium and having a carbon content between 0.2 and 0.7, preferably between 0.4 and 0.6% by weight and an oxygen/carbon ratio of about 1 to 3 and at most 0.5% of impurities, as well as the annealed powder obtained according to the process.Type: GrantFiled: December 17, 1999Date of Patent: January 29, 2002Assignee: Höganäs ABInventors: Johan Arvidsson, Alf Tryggmo
-
Patent number: 6331688Abstract: The present invention concerns the use of a pre-alloyed atomised powder in combination with at least one melting electrode wire in the SAW method. The electrode wire is an unalloyed or low-alloy metal wire and the metal powder is a metal powder containing a higher percentage of alloying elements than the electrode wire.Type: GrantFiled: March 23, 1999Date of Patent: December 18, 2001Assignee: Höganás ABInventors: Hans Hallén, Karl-Erik Johansson
-
Patent number: 6303077Abstract: The invention concerns a method of monitoring and controlling the furnace atmosphere when sintering PM compacts. According to the invention, the gases determining the carbon and oxygen potentials are measured continuously.Type: GrantFiled: November 24, 1999Date of Patent: October 16, 2001Assignee: Höganäs ABInventors: Johan Arvidsson, Ola Eriksson
-
Patent number: 6300702Abstract: A stator assembly for an electrical machine comprises a core made of a magnetic material. The core has an annular yoke (2) and a plurality of teeth (3) spaced circumferentially on the annular yoke and extending radially therefrom. The spaces between the teeth define circumferentially spaced winding slots (6). A stator winding is carried by the stator core and has coil turns located around the teeth and in the winding slots. Each tooth and a radially adjoining part (4) of the yoke have varying axial dimensions in order to adjust the magnetic flux to an optimal flux density in each part of the magnetic flux path in the stator. The annular yoke (2) may extend axially past the teeth (3) at least at one of the axial sides thereof.Type: GrantFiled: September 18, 2000Date of Patent: October 9, 2001Assignee: Höganäs ABInventors: Alan G. Jack, Barrie Mecrow
-
Patent number: 6261514Abstract: The invention concerns a method of preparing sintered products having high tensile strength and high impact strength comprising the steps of forming a mixture by mixing an iron powder including 1-4% by weight of Cr, 0.2-0.8% by weight of Mo 0.09-0.3% by weight % of Mn, less than 0.01% of C, less than 0.25% by weight of O, 0-1.2% of graphite, a high temperature lubricant and optionally an organic binder; preparing a heated powder composition by heating the mixture to a temperature above ambient temperature; transferring the heated powder composition to a preheated die; forming a compacted body by compacting the heated powder composition in the die at an elevated temperature; and forming a sintered product by sintering the compacted body at a temperature of at least 1220° C.Type: GrantFiled: May 31, 2000Date of Patent: July 17, 2001Assignee: Höganäs ABInventors: Caroline Lindberg, Johan Arvidsson
-
Patent number: 6245165Abstract: The present invention concerns a hydrogen storage alloy powder composition for nickel metal hydride rechargeable batteries. The powder is distinguished by a fine dendritic stnucture and is prepared by gas atomising a metal melt and rapidly cooling the gas atomised powder, which is subsequently heat treated and pulverised.Type: GrantFiled: December 2, 1999Date of Patent: June 12, 2001Assignee: Hoganas ABInventors: Johan Arvidsson, Ralf Carlström, Hans Hallén, Sture Löfgren
-
Patent number: 6235078Abstract: The present invention concerns additives for non-ferrous, liquid metals. The additives consist of compacted bodies of essentially pure iron particles.Type: GrantFiled: May 20, 1999Date of Patent: May 22, 2001Assignee: Höganäs ABInventor: Karl-Axel Barkentin
-
Patent number: 6231635Abstract: The invention concerns a lubricant for powder metallurgical compositions containing 10-60% by weight of a lithium salt of a fatty acid; 0-40% by weight of a zinc salt of a fatty acid and 40-90% by weight of a fatty acid bis-amide. 10-60% by weight of the lubricant is made up by the lithium and the zinc salt.Type: GrantFiled: February 1, 1999Date of Patent: May 15, 2001Assignee: Höganäs ABInventors: Masaaki Suzuki, Toshio Serita, Norio Ukai, Hiroyasu Saitoh
-
Patent number: 6120575Abstract: The invention concerns a process for the preparation of a free flowing agglomerated iron-based powder comprising mixing dry ingredients of: a) 63-95% by weight of a fine base powder consisting essentially of iron and having a particle size essentially less than 75 .mu.m; b) 5-20% by weight of a lubricating phase having a particle size essentially less than 120 .mu.m, preferably less than 60 .mu.m; c) 0-15% by weight of a hard phase material having a particle size essentially less than 10 .mu.m; and d) 0-7% of additives in a mixing chamber; evacuating the mixing chamber; filling the mixing chamber with an insert gas, mixing the ingredients with at most 1% by weight of a binding agent, and adding a solvent and drying the obtained powder.Type: GrantFiled: June 4, 1999Date of Patent: September 19, 2000Assignee: Hoganas ABInventors: Johan Arvidsson, Fredrik Emilsson
-
Patent number: 6027544Abstract: The invention concerns a process for producing a low-oxygen, low-carbon iron-based powder. The process comprises the steps of preparing a powder essentially consisting of iron and optionally at least one alloying element selected from the group consisting of chromium, manganese, copper, nickel, vanadium, niobium, boron, silicon, molybdenum, tungsten, decarburizing the powder in an atmosphere containing at least H.sub.2 and H.sub.2 O gases, measuring the concentration of at least one of the carbon oxides (alternatively gases) formed during the decarburisation process, or measuring the oxygen potential in at least 2 points located at a predetermined distance from each other in the longitudinal direction of the furnace, adjusting the content of the H.sub.2 O gas in the decarburizing atmosphere with the aid of the measurement. Another alternative concerns measuring the carbon oxides in combination with measuring the oxygen potential.Type: GrantFiled: January 21, 1999Date of Patent: February 22, 2000Assignee: Hoganas ABInventor: Johan Arvidsson
-
Patent number: 5997605Abstract: The present invention concerns a method of producing powder-metallurgical compacted components, which during subsequent processing are split into individual parts mating in pairs, sintered and optionally heat-treated and remated. According to the process, an iron-based powder is compacted, the obtained green body is fracture-split into at least two parts, which are subsequently sintered and optionally heat-treated. The obtained sintered parts are then remated.Type: GrantFiled: March 31, 1999Date of Patent: December 7, 1999Assignee: Hoganas ABInventors: Nils Carlbaum, Bjorn Johansson
-
Patent number: 5969276Abstract: The invention concerns an iron-based powder for powder-metallurgically producing components by powder compacting and sintering. The powder contains 0.25-2.0% by weight of Mo, 1.2-3.5% by weight of Mn, 0.5-1.75% by weight of Si and 0.2-1.0% by weight of C and not more than 2% by weight of impurities including less than 0.25% by weight of Cu. The invention also includes a method for preparing sintered components from this iron powder, as well as the sintered products.Type: GrantFiled: May 19, 1997Date of Patent: October 19, 1999Assignee: Hoganas ABInventor: Caroline Lindberg