A method of the continuous casting of molten metal by continuously withdrawing a strand is disclosed. The method is characterized in that the thickness of the strand is continuously reduced at a rate of 0.5 mm/min to less than 2.5 mm/min in the region between the point of time when the center of the strand has a temperature corresponding to a solid-phase ratio being within the range of 0.1 to 0.3 and the point of time when said temperature-has dropped to a level corresponding to the solid-phase ratio at the limit of fluidization, while substantially no reduction in thickness is effected in the region between the point of time when the center of the strand has a temperature corresponding to the solid-phase ratio at the limit of fluidization and the point of time when said temperature has dropped to the solidus line.

Continuous casting method

Three or more electromagnets are arranged along the direction of the longer sides of a mold, and, while an oscillating magnetic field is being generated, the peak position of the oscillating magnetic field is moved along the direction of the longer sides of the mold.

Continuous casting method for steel

PROBLEM TO BE SOLVED: To provide a continuous casting method which does not need expensive computing equipment, moreover, does not receive the influence of a facility status varying from hour to hour, and can suppress the generation of surface crack of a cast slab within a continuous casting machine.SOLUTION: This continuous casting method of a cast slab using a continuous casting machine having a bending zone which bends the cast slab while water-cooling the cast slab and a straightening zone which straightens the bent cast slab into a flat plate while water-cooling the bent cast slab is characterized in that: when measuring the surface temperature of the cast slab in the bending zone and the straightening zone with a radiation thermometer which detects the thermal radiation light radiated from the surface of the cast slab, the influence of scattering by the interface of moisture and air in the light path of the thermal radiation light between the surface of the cast slab and the radiation thermometer is suppressed, while making the surface temperature of the cast slab in the bending zone and the straightening zone measured by the thermal radiation meter 800°C or higher, the surface temperature variation of the cast slab in the bending zone and the straightening zone measured by the thermal radiation meter is made to be less than 75°C/min.

PROBLEM TO BE SOLVED: To provide a continuously cast ingot and a thick steel plate containing Nb and Ti combinedly and having such a superior hydrogen-induced crack (HIC) resistance that cracking area ratios (CAR) in HIC test is 4% or less. SOLUTION: The continuously cast ingot and the thick steel plate comprises 0.03-0.10% C, 0.05-0.4% Si, 0.8-1.8% Mn, 0.010% or less P, 0.002% or less S, 0.01-0.10% Nb, 0.005-0.03% Ti, 0.005-0.06% Al, 0.0005-0.0060% Ca, 0.0015-0.007% N and the balance being Fe with impurities; have a chemical composition satisfying an inequality of 1.48-1.5×Si-14.3×Ti-73×N>0.72; and further, in the central segregation parts of the ingot and the steel plate, contain such inclusions that the area density of (Ti, Nb)(C, N)-based inclusions exceeding 10 μm in length is 2 pieces/mm 2 or fewer and the area density of the (Ti, Nb)(C, N)-based inclusions of 1-10 μm in length is 2-200 pieces/mm 2 . The ingot and the steel plate may contain at least one kind of metal content selected from the group consisting of 0.5% or less of Cu, 1.0% or less of Ni, 1.5% or less of Cr, 1.0% or less of Mo and 0.2% or less of V. COPYRIGHT: (C)2008,JPO&INPIT

Continuously cast ingot for thick steel plate, its manufacturing method, and thick steel plate

The invention relates to a method for the continuous casting of slab, thin slab, bloom, preliminary section, round section, tubular section or billet strands (1) and the like from liquid metal in a continuous casting plant (2) in which metal discharges perpendicularly downwards from a mould (3), wherein the metal strip (1) is then guided vertically downwards along a perpendicular strand guide (4) and is cooled in the process, wherein the metal strip (1) is then defelcted from the vertical direction (V) into the horiziontal direction (H) and wherein mechanical forming (5) of the metal strip (1) is effected in the final region of the deflection into the horizonal direction (H) or after the deflection into the horizontal direction (H). In order to obtain a surface which has as little scale as possible, provision is made according to the invention for the metal strip (1) to be cooled with a heat transfer coefficient of between 2500 and 20 000 W/(m2 K) in a first section (6, 6A, 6B) in the conveying direction (F) of the metal strip (1) downstream of the mould (3) and upstream of the mechanical forming (5), wherein the surface of the metal strip (1) is heated to a temperature above Ac3 or Ar3 in the conveying direction (F) downstream of the cooling in a second section (7) by heat compensation in the metal strip (1) without or with reduced cooling of the surface of the metal strip (1), after which, in a third section (8), the mechanical forming (5) is effected. The invention also relates to a continuous casting plant, in particular for carrying out this method.

Method and apparatus for continuous casting

PROBLEM TO BE SOLVED: To secure the sufficient performances in an electromagnetic brake and an electromagnetic stirring, related to a method for continuously casting steel while controlling the flowing of molten steel in a mold by using an electromagnetic coil unit useable for the electromagnetic brake together with the electromagnetic stirring, for example, when a slab is continuously cast. SOLUTION: This continuous casting method is the one, with which the electromagnetic brake or the electromagnetic stirring is selectively acted to the molten steel 2 by making to flow a direct current or multi-phase alternating current having ≥3 phases to coils arranged at the outer circumference of the long wall sides 3b. The coils are arranged to the same pieces on each long wall side and (2n+2) (n is natural number) in the total in the mold. Each coil set has two pieces of coils wound on the outer circumferential part in the respective magnetic pole iron core and one piece of coil wound on the outer circumferential part with two pieces of magnetic pole iron cores together. At the electromagnetic stirring time, in the adjacent coils at each long wall side, the multi-phase alternating current having 90° to 120° current phase difference is made to flow. Further, at the electromagnetic braking time, the direct current is made to flow to the one piece of coil wound on the outer circumferential part to each coil set with two pieces of magnetic pole iron cores together, or the direct current is made to flow three pieces of coils. COPYRIGHT: (C)2007,JPO&INPIT

Method for continuously casting steel

PURPOSE:To reduce internal defect in a cast slab, to obtain the small piecing diameter at the time of manufacturing a pipe with hot-extrusion to enhance the material yield by setting plural rotating magnetic field type electromagnetic stirring devices in series and applying each electromagnetic stirring at the specific position at the time of executing the horizontal continuous casting. CONSTITUTION:At the time of producing the billet or a bloom with the horizontal continuous casting, at least tree steps of the rotating magnetic field type electromagnetic stirring devices are set in series. Then the first step of the electromagnetic stir is applied at the position corresponding to the solidified starting position in a mold. Successively, the second step of the electromagnetic stir is applied between the outlet of the mold and the position, where the solid- phase ratio at the center of the cast slab does not exceed zero. Further, the third step of the electromagnetic stir is applied from the position, where the solid-phase ratio at the center of the cast slab is in the range of >0.1 and <0.3, to the position where this ratio does not exceed 0.7. By this method, the formation of center porosity or cavity at the time of executing the horizontal continuous casting can be restrained, and the material yield at the time of manufacturing the pipe with the hot extrusion can be improved.

Horizontal continuous casting method

PROBLEM TO BE SOLVED: To provide a continuous casting method capable of producing a slab having stable inside quality by suppressing the occurrence of fine cracks caused by rolling reduction in the boundary between a negatively-segregated part and a bulk part. SOLUTION: Regarding the continuous casting method in which a slab including an un-solidified part is subjected to rolling reduction using at least a pair of rolling reduction rolls arranged in a continuous casting machine or at the edges of the machine, and, solidified shells on both the sides in the thickness direction of the slab are press-stuck to form a negatively-segregated part in the vicinity of the central part in the thickness direction of the slab after solidification, a product between the thickness D(mm) of the negatively-segregated part in the thickness direction of the slab and the content of an S component [S](ppm) in the steel is allowed to satisfy 0 COPYRIGHT: (C)2011,JPO&INPIT

晃三太田

Papers

Method for continuously casting steel

Horizontal continuous casting method

Continuous casting method for steel and extra-thick steep plate

晃三 太田

Papers

Method for continuously casting steel

Horizontal continuous casting method

Continuous casting method for steel and extra-thick steep plate

晃三太田