Described herein are techniques for improving the grain structure of a metal product by applying ultrasonic energy to a continuously cast metal product at a position downstream from the casting region and allowing the ultrasonic energy to propagate through the metal product to the solidification region. At the solidification region, the ultrasonic energy can interact with the growing metal grains, such as to deagglomerate and disperse nucleating particles and to disrupt and fragment dendrites as they grow, which can promote additional nucleation and result in smaller grain sizes.

Disclosed are an electromagnetic stirring device and a method for a secondary cooling zone during slab continuous casting. The device comprises an electromagnetic stirring device main body comprising a protection housing (3), a phase sequence control assembly, an iron core (4) and an electromagnetic coil (5) for carrying out variable-direction electromagnetic stirring on molten steel by means of three-phase current phase sequence transformation; an opening adjustment assembly comprising an air cylinder (7), a fixed base (8), a movable joint shaft (12) and a silicon steel sheet group insert (13) for adjusting online the opening degree of the closed annular iron core by means of a movable joint structure; and the secondary cooling assembly comprising a cooling water inlet (9) and a cooling water nozzle (10) for cooling the electromagnetic coil and spraying cooling water to a surface of a cast slab (1).

The measuring device includes: a detecting section including a coil which detects a change in a value of impedance caused by a change in a mold level; an amplifying section which amplifies an output of the detecting section; a pre-pouring calibration section which determines a reference value of a positive feedback ratio of the amplifying section in environmental conditions before pouring of molten metal; and a mold oscillation signal calibration section which obtains a standard value of difference in an output of the measuring device, the standard value of difference corresponding to a known value of amplitude of mold oscillation when the positive feedback ratio is the reference value, obtains a deviation of measurement based on a difference between the maximum value and the minimum value of the output in mold oscillation and the standard value, and corrects the positive feedback ratio within a predetermined range including the reference value.

A semi-continuous casting equipment for thin-walled alloy castings with equal outer diameter, optimized by synergistic action of traveling magnetic fields and ultrasonic wave, includes: a melting and insulation device, a heat insulation panel, a traveling magnetic field generator and a water-cooled crystallizer sequentially positioned on a working platform; an outer mold positioned on the water-cooled crystallizer and sleeved the traveling magnetic field generator; a mold core inside the outer mold defining a casting cavity; a bottom plate below the mold core capable of sliding against and along an inner side of the outer mold; two position control units supported by the working platform; an ultrasonic limit baffle moveably engaged with the position control units; an ultrasonic wave generator affixed on the ultrasonic limit baffle and extended to the casting cavity; a motion system controlling up and down movement of the bottom plate and the position control units through a gear transmission mechanism.

An electromagnetic stirring device and a method for a secondary cooling zone during slab continuous casting. The device has a main body, an opening adjustment assembly, and a secondary cooling assembly. The main body has a protection housing (3), a phase sequence control assembly, an iron core (4) and an electromagnetic coil (5) for carrying out variable-direction electromagnetic stirring on a molten steel by a three-phase current phase sequence transformation. The opening adjustment assembly has an air cylinder (7), a fixed base (8), a movable joint shaft (12) and a silicon steel sheet group insert (13) for adjusting online opening degree of the closed annular iron core by a movable joint structure. The secondary cooling assembly has a cooling water inlet (9) and a cooling water nozzle (10) for cooling the electromagnetic coil and spraying cooling water to a surface of a cast slab (1).

A defect detection and remediation system can be used to detect and remediate sub-surface defects within a cast metal during the continuous casting stage. The system can include a detection device having one or more detection units to detect a defect within the cast metal using ultrasonic waves and a remediation device having one or more remediation units to remediate the defect detected by the detection device in a target area of the cast metal containing the detected defect.

A system for detection of the level of a liquid metal within a crystallizer of a mold has a detection system. The detection system is based on a transmission of at least one signal transmitted toward a crystallizer having the liquid metal therein and a reception of a reflection of the transmitted signal. A first ultrasonic element transmits a ultrasonic elastic wave and a second ultrasonic element receives the ultrasonic elastic wave. A processor measures a time elapsed between transmission and reception and correlates the elapsed time relative to the level of liquid metal in the crystallizer.

A continuous steel casting method includes producing a strand. The producing of the strand includes pouring molten steel into a mold of a continuous casting machine and withdrawing a solidified shell from the mold, the solidified shell being a solidified portion of the molten steel. The method includes applying a static magnetic field to at least a portion of a region of the strand, the strand being in the continuous casting machine, the region being a region where a solid fraction fs at a thickness-wise middle position of the strand is in a given range, the static magnetic field having a magnetic field strength of greater than or equal to 0.15 T and being in a direction orthogonal to a direction in which the strand is withdrawn, the static magnetic field being applied at an application time ratio of greater than or equal to 10%.

A semi-continuous casting equipment for thin-walled alloy castings with equal outer diameter, optimized by synergistic action of traveling magnetic fields and ultrasonic wave, includes: a melting and insulation device, a heat insulation panel, a traveling magnetic field generator and a water-cooled crystallizer sequentially positioned on a working platform; an outer mold positioned on the water-cooled crystallizer and sleeved the traveling magnetic field generator; a mold core inside the outer mold defining a casting cavity; a bottom plate below the mold core capable of sliding against and along an inner side of the outer mold; two position control units supported by the working platform; an ultrasonic limit baffle moveably engaged with the position control units; an ultrasonic wave generator affixed on the ultrasonic limit baffle and extended to the casting cavity; a motion system controlling up and down movement of the bottom plate and the position control units through a gear transmission mechanism.

A continuous steel casting method includes producing a strand. The producing of the strand includes pouring molten steel into a mold of a continuous casting machine and withdrawing a solidified shell from the mold, the solidified shell being a solidified portion of the molten steel. The method includes applying a static magnetic field to at least a portion of a region of the strand, the strand being in the continuous casting machine, the region being a region where a solid fraction fs at a thickness-wise middle position of the strand is in a given range, the static magnetic field having a magnetic field strength of greater than or equal to 0.15 T and being in a direction orthogonal to a direction in which the strand is withdrawn, the static magnetic field being applied at an application time ratio of greater than or equal to 10%.