Abstract: During the treatment of electrical steel, a careful combination of heat treatment of the slab with a specific primary recrystallization and nitriding treatment allows for control of the distribution, quantity and dimensions of precipitates in order to obtain a homogeneous precipitation of nitrogen compounds by direct reaction of the absorbed nitrogen with aluminum during the nitriding step.
Type:
Grant
Filed:
June 17, 1999
Date of Patent:
June 18, 2002
Assignee:
Acciai Speciali Terni S.p.A.
Inventors:
Stefano Fortunati, Stefano Cicale′, Giuseppe Abbruzzese, Susanna Matera
Abstract: A funnel geometry of a mold for the continuous casting of metal, wherein the mold has a pouring portion with cooled long side walls and short side walls, wherein the pouring portion becomes narrower in the shape of a funnel in the casting direction until it reaches the size of the cast strand. In the funnel portion the inner contour of the long side walls is constructed convexly along a straight line connecting the upper edge of the mold and the outlet of the pouring portion.
Abstract: A process for producing the oscillation of a continuous casting mold, especially with the use of a hydraulically driven lifting device. So that the heat transfer to the mold and the formation of the casting shell can be effectively controlled, it is proposed that, for any given strand withdrawal rate, the zero line of the mold oscillations relative to the position of the surface of the steel in the mold be moved upward and/or downward during the casting process. As a result of this measure, the quality of the cast product is effectively improved.
Abstract: The production of grain-oriented electrical steel sheets is disclosed wherein grain growth in the steel is inhibited by a method comprising the regulation of the content of sulfur and manganese in the steel strp and the cold rolled strip is continuously nitrided at high temperature.
Type:
Grant
Filed:
December 9, 1999
Date of Patent:
March 26, 2002
Assignee:
Acciai Speciali Terni S.p.A.
Inventors:
Stefano Fortunati, Stefano Cicale', Giuseppe Abbruzzese
Abstract: In the production of grain-oriented electrical steel strip, the grain growth inhibition is controlled by balancing the copper, aluminum and carbonium content in order to control the type and quantity of precipitated second phases and obtain optimum grain dimensions during the decarburization annealing. This is done by using a continuous high-temperature thermal treatment in which nitrogen is diffused into the steel strip and aluminum is directly precipitated as aluminum nitride which controls the grain orientation of the final product.
Type:
Grant
Filed:
December 9, 1999
Date of Patent:
March 26, 2002
Assignee:
Acciai Speciali Terni S.p.A.
Inventors:
Stefano Cicale′, Stefano Fortunati, Giuseppe Abbruzzese
Abstract: A method for continuously casting thin metal products, the method comprising the operations of pre-heating a pair of refractory plates (7) for the lateral containment of a bath of molten metal constituted of a pair of counter-rotating rolls (1, 2) and of abutting said pair of plates (7) towards each lateral surface of the ends of said pair of rolls (1, 2), characterized in that it comprises the operations of applying a controlled elastic or elastic/plastic deformation to said pair of plates (7) at the contacting arc between the surface of the plates (7) and the peripheral portion of the ends of said rolls (1, 2), and controlling said elastic and/or elastic-plastic deformation of said pair of plates (7) during the whole casting process, so as to minimize the surface wear of the plates (7) and of the ends of the rolls (1, 2), and to guarantee the maintainment of a predetermined distance between said rolls (1, 2) and said plates (7) lower than a predetermined value, and to minimize the occurrence of leaks-of mol
Abstract: The present invention provides a feeder of molten metal for moulds of continuous casting machines comprising a cylindrical body (1) within which a main outflow duct (5) of the molten metal coming from the tundish is formed to which the cylindrical body (1) is connected by means of a frustoconical joint (2), formed integrally with the cylindrical body (1) at the upper end thereof, characterized in that the free end (3) of the cylindrical body (1) is of substantially frustopyramid shape and has a plurality of outlets (7, 8, 9, 10, 11) communicating with the main outflow duct (5).
Abstract: A process for the production of grain oriented silicon steel sheet which provides an optimization of the production of conventional, grain oriented silicon steel strips, by the use of an appropriate synergistic combination of the composition levels of some elements and appropriate treatments which result in the control of the presence and type of inhibitors, and by so doing, controlling the primary-recrystallization grain size.
Type:
Grant
Filed:
June 22, 1999
Date of Patent:
December 4, 2001
Assignee:
Acciai Speciali Terni S.p.A.
Inventors:
Stefano Fortunati, Stefano Cicale′, Giuseppe Abbruzzese
Abstract: In the production of high permeability electrical steel, the control of condition of thin slab continuous casting allows to obtain advantageous solidification structures and precipitates. This, in turn, allows to decritize the process for controlling the grain dimensions and to add nitrogen to the cold rolled sheet, such as to immediately form aluminum nitride.
Type:
Grant
Filed:
February 26, 1999
Date of Patent:
October 2, 2001
Assignee:
Acciai Speciali Terni S.p.A.
Inventors:
Stefano Fortunati, Stefano Cicale', Giuseppe Abbruzzese
Abstract: A method for pickling products in a metal alloy containing iron, and products in titanium and alloys thereof, in the absence of nitric acid as an oxidizing agent, and for the recovery of the exhausted solutions, characterized in that the recovery of the exhausted solutions deriving from pickling comprises the following steps: sending of the pickling solution, both as catholyte and as anolyte, in an electro-chemical cell optionally of the membrane type to separate the Fe2+ (or Ti2+) ions to be disposed of, from the Fe3+ (or of the Ti3+ and Ti4+) ions to be recovered, obtained by reduction at the cathode of the Fe3+ ions which are in the catholyte to Fe2+ (or of the Ti3+ and Ti4+ ions to Ti2+) and of oxidation at the anode Fe2+ (or Ti2+) ions which are in the anolyte to Fe3+ (to Ti3+ and Ti4+); treating the catholytic solution coming out of the cell and enriched in Fe2+ (or Ti2+) ions as to allow the separation in two phases, a
Abstract: Stainless steel pickling process in which a pickling solution containing HF and Fe3+ ions as essential components is used, and wherein the oxidation to Fe3+ of the Fe2+ formed during the process in order to maintain the Fe3+ concentration to the predetermined value, is electrolytically carried out by submitting the pickling solution as it is to an oxidation process in an electrolytic cell equipped with anode made of inalterable materials chosen among graphite, granular coal, lead and with cathodes made of stainless steel, graphite or other unalterable materials, said cell working with an applied tension between 1 and 8 V and with an anodic current density between 0.4 and 15 A/dm2.
Type:
Grant
Filed:
January 11, 1999
Date of Patent:
April 3, 2001
Assignees:
Henkel Kommanditgesellschaft auf Aktien, Acciai Speciali Terni S.p.A.
Inventors:
Ioannis Demertzis, Paolo Giordani, Cesare Pedrazzini, Maurizio Busnelli
Abstract: A mold for the continuous casting of metal includes a pouring portion with cooled long side walls and short side walls, wherein the pouring portion becomes narrower in the shape of a funnel in the casting direction until it reaches the size of the cast strand. In the funnel portion, the inner contours of the long side walls have in the casting direction from the top toward the bottom at least two points which have the property that they determine a straight line along which the inner contours of the long side walls are formed with at least one concave section and with at least one convex section in any selected sequence.