Patents by Inventor Rama Ballav Mahapatra
Rama Ballav Mahapatra has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10046384Abstract: A side dam for a continuous twin roll caster with a body of refractory material shaped to form a side dam and having edge portions adapted to engage end portions of casting rolls of a twin roll caster and having a nip portion adapted to be adjacent a nip between the casting rolls and having upper portions extending across the side dam to form a lateral restraint for a casting pool of molten metal during operation in the twin roll caster; and a pocket between 5 and 50 mm in depth formed in the body between the edge portions and forming shoulder portions in the body between the edge portions and the pocket adapted to be worn as a casting campaign continues until the pocket is reached and continuing to be worn away at level of base portions of the pocket until casting is completed.Type: GrantFiled: September 7, 2016Date of Patent: August 14, 2018Assignee: Nucor CorporationInventors: Kevin Keown, Tao Wang, Rama Ballav Mahapatra
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Patent number: 9744589Abstract: Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 micrometers Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.Type: GrantFiled: January 7, 2015Date of Patent: August 29, 2017Assignee: Nucor CorporationInventors: Rama Ballav Mahapatra, David W. McGaughey, Jay Jon Ondrovic, Tim Patterson, Mike Schueren
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Publication number: 20170087623Abstract: A side dam for a continuous twin roll caster with a body of refractory material shaped to form a side dam and having edge portions adapted to engage end portions of casting rolls of a twin roll caster and having a nip portion adapted to be adjacent a nip between the casting rolls and having upper portions extending across the side dam to form a lateral restraint for a casting pool of molten metal during operation in the twin roll caster; and a pocket between 5 and 50 mm in depth formed in the body between the edge portions and forming shoulder portions in the body between the edge portions and the pocket adapted to be worn as a casting campaign continues until the pocket is reached and continuing to be worn away at level of base portions of the pocket until casting is completed.Type: ApplicationFiled: September 7, 2016Publication date: March 30, 2017Applicant: NUCOR CORPORATIONInventors: Kevin KEOWN, Tao WANG, Rama Ballav MAHAPATRA
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Publication number: 20150129154Abstract: Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 micrometers Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.Type: ApplicationFiled: January 7, 2015Publication date: May 14, 2015Inventors: Rama Ballav MAHAPATRA, David W. MCGAUGHEY, Jay Jon ONDROVIC, Tim PATTERSON, Mike SCHUEREN
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Patent number: 8960264Abstract: Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.Type: GrantFiled: March 14, 2013Date of Patent: February 24, 2015Assignee: Nucor CorporationInventors: Rama Ballav Mahapatra, David W. McGaughey, Jay Jon Ondrovic, Tim Patterson, Mike Schueren
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Patent number: 8960265Abstract: Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.Type: GrantFiled: October 29, 2010Date of Patent: February 24, 2015Assignee: Nucor CorporationInventors: Rama Ballav Mahapatra, David W. McGaughey, Jay Jon Ondrovic, Tim Patterson, Mike Schueren
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Publication number: 20140261905Abstract: A method for making alloy strip by continuous casting with tensile strength of at least 900 MPa and total elongation of at least 30%, strip with tensile strength of at least 1200 MPa and total elongation of at least 20%, or strip with tensile strength of at least 1500 MPa and total elongation of at least 15%. Molten metal is introduced forming a casting pool supported on the casting rolls and counter-rotating the A heat flux is provided with a peak heat flux >20 Mw/m2. The strip is cooled at 1000-3000 K/sec. A roll biasing force >40 kN/meter of casting roll length is applied to form thin metal strip. The strip is then conveyed through a first enclosure with an atmosphere having an oxygen content of <5%. The cast strip is rolled through a rolling mill and reduced and modification of the microstructure is initiated.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Applicant: CASTRIP, LLCInventors: Walter N. Blejde, Rama Ballav Mahapatra, Daniel Geoffrey Edelman
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Publication number: 20140008032Abstract: A composite side dam for a continuous twin roll caster includes a substrate made of a refractory material capable of withstanding casting temperature and having edge portions adapted to engage casting rolls and having a nip portion adjacent a nip between casting rolls and upper portions extending across the side dam to form a lateral restraint for a casting pool, an insert of at least 10 mm in thickness positioned in a pocket in the substrate and extending to engage the molten metal and extending from the upper portions of the substrate and positioned in the pocket to within 30 mm from the nip portion by insertion adjacent the upper portions of the substrate, and the insert adapted to fit into the pocket of the substrate to form a side dam formed of a refractory material having consumption rate less than 10 mm per hour. The material forming the insert may be between 40 and 60% SiAlON material and the remainder hBN material, or mullite material as described by FIG.Type: ApplicationFiled: June 27, 2013Publication date: January 9, 2014Applicant: NUCOR CORPORATIONInventors: Jay Jon ONDROVIC, Alan J. DENO, Mark SCHLICHTING, Rama Ballav MAHAPATRA
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Patent number: 8607847Abstract: A method of continuously casting thin strip dynamically controlling roll casting surface configuation by controlling the temperature of water flowing through the longitudinal water flow passages in a cyclindrical tube thickness of no more than 80 millimeters of counter rotated casting rolls, and varying the speed of the casting rolls with attenuation of the ends of the casting rolls with a casting roll drive system responsive to electrical signals received from sensors during a casting campaign.Type: GrantFiled: August 5, 2008Date of Patent: December 17, 2013Assignee: Nucor CorporationInventors: Mark Schlichting, Walter N. Blejde, Mike Schueren, Rama Ballav Mahapatra
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Patent number: 8607848Abstract: A method of continuously casting thin strip dynamically controlling roll casting surface configuration by controlling the temperature of water flowing through the longitudinal water flow passages in a cylindrical tube thickness of no more than 80 millimeters of counter rotated casting rolls, and varying the speed of the casting rolls with attenuation of the ends of the casting rolls with a casting roll drive system responsive to electrical signals received from sensors during a casting campaign.Type: GrantFiled: July 29, 2009Date of Patent: December 17, 2013Assignee: Nucor CorporationInventors: Mark Schlichting, Walter N. Blejde, Mike Schueren, Rama Ballav Mahapatra
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Publication number: 20130174995Abstract: Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.Type: ApplicationFiled: March 14, 2013Publication date: July 11, 2013Applicant: Nucor CorporationInventors: Rama Ballav Mahapatra, David W. McGaughey, Jay Jon Ondrovic, Tim Patterson, Mike Schueren
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Publication number: 20130119094Abstract: A method of casting metal strip and equipment therefor where an elongated metal delivery nozzle extending along in a continuous caster with at least one segment having a main portion adapted to deliver molten metal in the casting pool above the nip along the metal delivery nozzle and an end portion adjacent side dams having a reservoir portion with first and second passages adapted to deliver molten metal into a molten metal pool adjacent the side dams while shells are forming on the casting rolls. The first passages are adapted to deliver molten metal shallowly into the casting pool adjacent the side dams, and the second passages adapted to deliver molten metal deeper into the casting pool than the first passages adjacent the side dams to inhibit formation of skulls during the formation of the cast strip during a casting campaign.Type: ApplicationFiled: May 4, 2012Publication date: May 16, 2013Applicant: NUCOR CORPORATIONInventors: Rama Ballav Mahapatra, Hisahiko Fukase
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Patent number: 8322402Abstract: During continuously casting metal strip, delivering molten metal supported on the casting surfaces of the casting rolls, and counter rotating the casting rolls to form metal shells on the casting surfaces brought together at the nip to deliver cast strip downwardly with a controlled amount of mushy material between the metal shells, determining at a reference location downstream from the nip a target temperature for the cast strip corresponding to a desired amount of mushy material between the metal shells of the cast strip, sensing the temperature of the cast strip cast downstream from the nip at the reference location and producing a sensor signal corresponding to the sensed temperature, and causing an actuator to vary the gap at the nip between the casting rolls in response to the sensor signal received from the sensor and processed to determine the temperature difference between the sensed temperature and the target temperature.Type: GrantFiled: September 20, 2010Date of Patent: December 4, 2012Assignee: Nucor CorporationInventors: Walter N. Blejde, Rama Ballav Mahapatra, Mark Schlichting
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Patent number: 8191610Abstract: Apparatus for continuously casting metal strip includes a pair of counter-rotatable casting rolls laterally positioned to form a nip there between through which thin strip can be cast, a pair of confining side dams adjacent the ends of the casting rolls capable of confining a casting pool of molten metal supported on the casting rolls above the nip, each side dam having a surface capable of contacting the molten metal of the casting pool, with unraised portions and raised portions to form troughs with the unraised portions as base between the raised portion of the side dam and the casting surfaces of the casting rolls to guide the flow of molten metal, and a metal delivery system disposed above the nip and capable of discharging molten metal to form the casting pool supported on the casting rolls.Type: GrantFiled: November 24, 2009Date of Patent: June 5, 2012Assignee: Nucor CorporationInventors: Rama Ballav Mahapatra, Brian E. Bowman
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Patent number: 8176969Abstract: An apparatus for continuously casting thin strip includes a caster having a pair of casting rolls having a nip there between capable of delivering cast strip downwardly from the nip and an first enclosure capable of forming a protective atmosphere into which the strip can be formed in loop to extend over a plurality of rollers into pinch rolls with the strip having a strain of less than 0.4%, which may be provided by a plurality of rollers at entry of the strip into the pinch rolls to carry the strip into the pinch rolls, with at least a first entry roller having a diameter between 200 and 650 millimeters and being below a majority of other rollers.Type: GrantFiled: June 28, 2011Date of Patent: May 15, 2012Assignee: Nucor CorporationInventors: Andrew Edward Dixon, Gary McQuillis, Rama Ballav Mahapatra, Leigh Wolley
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Patent number: 8047264Abstract: A metal strip casting apparatus and method of casting continuous metal strip include assembling a pair of counter-rotatable casting rolls having casting surfaces positioned laterally forming a nip between for casting, and delivering molten metal through a delivery nozzle disposed above the nip to form a casting pool supported on the casting rolls. The delivery nozzle includes at least one segment having a main portion and an end portion and an inner trough extending longitudinally through the main portion and into the end portion with end walls at opposite ends thereof, the inner trough communicating with outlets adjacent bottom portions formed in each segment adapted to deliver molten metal to a casting pool and the end portion having a reservoir portion having passages adapted to deliver molten metal to a casting pool.Type: GrantFiled: March 13, 2009Date of Patent: November 1, 2011Assignee: Nucor CorporationInventors: Brian E. Bowman, Rama Ballav Mahapatra, Peter A. Woodberry
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Publication number: 20110253336Abstract: An apparatus for continuously casting thin strip includes a caster having a pair of casting rolls having a nip there between capable of delivering cast strip downwardly from the nip and an first enclosure capable of forming a protective atmosphere into which the strip can be formed in loop to extend over a plurality of rollers into pinch rolls with the strip having a strain of less than 0.4%, which may be provided by a plurality of rollers at entry of the strip into the pinch rolls to carry the strip into the pinch rolls, with at least a first entry roller having a diameter between 200 and 650 millimeters and being below a majority of other rollers.Type: ApplicationFiled: June 28, 2011Publication date: October 20, 2011Applicant: NUCOR CORPORATIONInventors: Andrew Edward Dixon, Gary McQuillis, Rama Ballav Mahapatra, Leigh Wolley
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Patent number: 8016021Abstract: A method of producing cast steel strip having low surface roughness and low porosity by casting with molten steel having a total oxygen content of at least about 70 ppm and a free oxygen content between 20 and 60 ppm, and a temperature that allows a majority of any oxide inclusions to be in a liquidus state. The total oxygen content may be at least 100 ppm and the free oxygen content between 30 and 50 ppm. The steel strip produced by the method may have a per unit area density of at least about 120 oxide inclusions per square millimeter to a depth of about 2 microns from the strip surface.Type: GrantFiled: October 5, 2007Date of Patent: September 13, 2011Assignee: Nucor CorporationInventors: Walter N. Blejde, Rama Ballav Mahapatra, Lazar Strezov
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Patent number: 8002908Abstract: A steel product with a high austenite grain coarsening temperature having less than 0.4% carbon, less than 0.06% aluminium, less than 0.01% titanium, less than 0.01% niobium, and less than 0.02% vanadium by weight, and having fine oxide particles containing silicon and iron distributed through the steel microstructure having an average particle size less than 50 nanometers and may be between 5 and 30 nanometers. The steel product may have fine oxide particles distributed through the microstructure capable of restricting ferrite recrystallization for strain levels up to at least 10.0%, for temperatures up to 750° C. with holding times up to 20 minutes. The steel product may be made by continuous casting of steel strip introduced between the casting rolls to form a casting pool of molten carbon steel having a total oxygen content of at least 70 ppm usually less than 250 ppm, and a free oxygen content 20 and 60 ppm, counter rotating the casting rolls.Type: GrantFiled: February 2, 2009Date of Patent: August 23, 2011Assignee: Nucor CorporationInventors: Walter N. Blejde, Rama Ballav Mahapatra, James Geoffrey Williams, Frank Barbaro, Philip John Renwick, Harold Roland Kaul, Andrew Phillips, Christopher Ronald Killmore, Lazar Strezov
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Patent number: 7984748Abstract: An apparatus for continuously casting thin strip includes a caster having a pair of casting rolls having a nip there between capable of delivering cast strip downwardly from the nip and an first enclosure capable of forming a protective atmosphere into which the strip can be formed in loop to extend over a plurality of rollers into pinch rolls with the strip having a strain of less than 0.4%, which may be provided by a plurality of rollers at entry of the strip into the pinch rolls to carry the strip into the pinch rolls, with at least a first entry roller having a diameter between 200 and 650 millimeters and being below a majority of other rollers.Type: GrantFiled: July 3, 2008Date of Patent: July 26, 2011Assignee: Nucor CorporationInventors: Andrew Edward Dixon, Gary McQuillis, Rama Ballav Mahapatra, Leigh Wolley