Abstract: The present invention provides novel methods and apparatus for continuously casting molten metal in a block caster. In accordance with the present invention, novel track and drive systems are provided for reducing imperfections that can be created in a cast by movement of a beam chain through a casting cycle.

Abstract: An improved continuous casting mold and foot guide assembly includes a mold having a casting passage defined therein, a frame member, mounting structure for mounting the frame member to the mold for relative movement toward and away from an axis of the casting passage, and a strand support member for providing support to a strand of continuously cast material as it emerges from the casting passage. Biasing structure is provided for biasing the frame member toward the axis of the casting passage and, advantageously, is positioned so as not to occupy space that is behind the frame member. As a result, the assembly is compatible with all models of casting machines and will be less susceptible to degradation as a result of radiant heat and steam that is emitted from the strand during operation. In addition, a load cell is provided for monitoring the amount of relative force between the frame member and the strand during operation.

Abstract: The occurrence of porosity defects in solidifying metal can be predicted by a computer simulation numerically analyzing the solidification process of molten metal comprising (1) dividing a mold and a mold cavity into a plurality of elements; (2) providing each of the elements with material properties of casting metal and mold, and process variables as initial data; (3) calculating a liquid fraction of each of the elements in successive predetermined time increments to examine whether nor not each of the elements is in solid-liquid coexisting zone; (4) calculating pressure gradients between each of elements in the solid-liquid coexisting zone and neighboring elements thereof by numerically analyzing an interdendritic flow of the molten metal; (5) calculating gas pressure in the molten metal in each of elements in the solid-liquid coexisting zone; (6) comparing the gas pressure with an equilibrium pressure, and calculating a porosity amount for each of elements where the gas pressure is higher than the equilibr

Abstract: In a mold oscillation device for making oscillation of a mold used in a continuous casting machine, an acceleration sensor (22) detects the oscillation to produce an oscillation detection signal representative of said oscillation. The oscillation detection signal has a particular waveform. Responsive to the oscillation detection signal, a signal producing circuit (30) produces an adjusting signal with reference to the particular waveform. With reference to the adjusting signal, a control unit (16) controls the oscillation. In order to produce the adjusting signal, it is preferable that the signal producing circuit carries out a frequency analysis as regards the particular waveform.

Abstract: A device for detecting longitudinal cracks on slabs, in particular on steel slabs, issuing from a continuous casting, by way of eddy current measuring probes fed with an alternating voltage, and device for detecting variations in the voltage indicating the presence of a crack. The device for detecting longitudinal cracks includes on each side of upper and lower faces of the slab, a crack detection unit each including a measuring probe which undergoes a transverse reciprocating motion relative to the direction of travel of the slab, and a device for maintaining the measuring probe of each detection unit at a constant distance relative to the corresponding main face of the slab.

Abstract: Continuously cast metal billets are continuously passed by a symmetric light source comprising a plurality of single light sources arranged in a circle or in another way such that the light falls substantially symmetrically on the part of the surface of the metal billet which is to be detected in such a way that the surface of the metal billet which faces the light source is illuminated except for pinholes. Reflected light from the surface of the billet is detected by a linescan camera arranged centrally in relation to the light source, which camera has a scanning direction normal to the direction of movement of the metal billet, whereby pinholes are detected by registration of reflected light intensity below a preset threshold value.

Abstract: In a continuous casting method, a melt surface condition within a mold is monitored for melt surface abnormalities such as boiling, lack of powder, and a condition of slag beard formation by using image sensors. Also, a condition of Deckel formation is detected by using a load sensor through a sensor rod. Based on the monitored conditions, a casting speed, a flow rate of gas blown into a pouring nozzle, a flow rate of a melt poured into the mold, scatter of powder, and the like, are controlled to prevent the occurrence of the melt surface abnormalities, as well as removing a slag beard by a hitting oscillator and removing Deckels by the sensor rod.

Abstract: A roll monitor sled data handling system comprising a roll monitor sled and an off-line data handling system. The roll monitor sled consists of a housing having mounted thereon sensors which measure the roll gap and the angle of the rolls. These sensors create analog signals which are converted to digital signals and transmitted to an on-board computer. The processed digital signals include digital signals corresponding to analog signals created when the sensors are in contact with the rolls. The computer processes the digital signals and transmits the processed data to a radio modem. The radio modem transmits the processed digital signals to the off-line data display system. The data display system comprises a receiver modem, a host computer, a digital to analog converter and a display and chart recorder. The selected data is displayed and/or recorded to give the user a "real-time indication" of the critical dimensions of the rolls in a continuous casting machine.

Abstract: Upstream of the dies (14) internally insulated in the upper region is a casting furnace and a runner system, which latter comprises a distributor through feeding all the dies (14) with metal at an identical level (60). In the region situated below an inner ring (32), a gas cushion (54) which prevents direct contact of the die (14) with the molten metal (30) is maintained, and oil is injected into this region. A joint main having distribution lines conducts air or an inert gas having the same, slight overpressure into all the dies (14). The relative pressure between a desired value dependent on the metal level (H.sub.1) and computed by program and an actual value measured in the main (62) serves for regulation and monitoring. Upon overshooting of the programmed, maximum deviation of the controlled variable, a processor triggers a manipulated variable for the actuator of the pressure control valve.

Abstract: A method of quantitatively determining the molten pool configuration in melting of metals. The method includes the steps of introducing hafnium metal seeds into a molten metal pool at intervals to form ingots, neutron activating the ingots and determining the hafnium location by radiometric means. Hafnium possesses exactly the proper metallurgical and radiochemical properties for this use.

Abstract: According to this process: the position in respect of height of the "molten metal (2)/liquid slag (3)" interface (M) is continuously determined. Further the position of an isotherm (IS) located at the "liquid slag (3)/powder layer (4)" interface is continuously determined by automatically controlling the position of a thermocouple (8) on this isotherm and by measuring the displacements of this thermocouple.By comparing the position in respect of height of the molten metal/liquid slag interface (M) with the position in respect of height of the isotherm (IS), the thickness and thus the variations in thickness of the liquid slag are continuously deduced.

Abstract: A method of detecting the level of molten metal existing within a mold comprises the steps of disposing a transmission coil and a receiving coil opposite to each other with the mold interposed therebetween, applying an AC voltage to the transmission coil for producing an alternating magnetic flux such that at least a part of the magnetic flux passes through the mold and the molten metal, if any, and reaches the receiving coil, and determining the level of the molten metal on the basis of at least one of a voltage value and a phase of an AC signal induced in the receiving coil by the alternating magnetic flux, and an apparatus for carrying out the above method.

Abstract: The flatness of a casting belt in a continuous metal casting machine is continuously monitored and thereby also the condition of its thermal protective coating. One or more non-contacting eddy-current sensing probes are placed in proximity to the reverse or coolant side of a belt for sensing and measuring the distance of the belt from the probe to reveal irregularities in the flatness of the belt while it travels past the probe. A deficiency of insulative belt coating can cause variations in belt flatness during casting. By monitoring such variations an operator of the continuous casting machine is alerted that the coating needs to be retouched or replaced without interrupting the casting process. Or such monitoring can alert the operator that the belt has become inherently not flat. A similar proximity sensing probe is utilized for the purpose of supplying an instant report of the initial entrance of molten metal into the casting cavity adjacent to a casting belt at the start of a cast.

Abstract: A method and apparatus for predicting the likelihood of a break-out during continuous casting of molten metal in a vertical mold. A continuous determination is made of (a) the location within the mold of the molten metal level and (b) the peak temperature location within the mold, both in relation to the top of the mold. The vertical distance between (a) and (b) is noted, and that distance is continuously monitored to detect any increase therein. A substantial increase indicates the likelihood of a breakout unless corrective action is taken.

Abstract: A method for continuous casting of thin slab ingots with reduced thickness following immediately the casting particularly of steel under utilization of a mold which is open at the bottom and under further utilization of roller pairs arranged along the withdrawal path, at least some of them are driven and at least some of the rollers are hydraulically adjustable perpendicular from the path so as to act as ingot deforming rolls. The invention is further improved by determining the speed of driven rollers, and the pressure force of adjustable roller pairs acting against the ingot and providing feedback control for the speed and the force. Additionally, providing a master control action for the speed control such that a point of solidification is dynamically maintained in a particular geometric position as far as the passing ingot is concerned; and by limiting the adjustment of rollers as far as the gap between pairs of such rollers is concerned downstream from that point.

Abstract: A method for continuously monitoring and/or controlling the cooling capacity of a liquid coolant containing gas bubbles. The method comprising the steps of: (a) measuring the size and number density of the gas bubbles it he liquid coolant by use of a sensor means to infer a heat transfer characteristic of the liquid coolant; and (b) varying the amount of gas that is being mixed with the liquid coolant so that the inferred heat transfer characteristic is within a predetermined range.

Abstract: A continuous casting process introduces the factor of rate temperature change for detecting break out in the cast metal. Introduction of rate of temperature change as a parameter representative of the cast metal condition is successful for avoiding the influence of variation of the casting condition, fluctuation of the powder to be introduced between the casting mold wall and the cast metal, casting speed and so forth. For achieving accurate detection of break out of the cast metal by introducing the temperature change factor, casting mold wall temperatures are measured at various measuring points which are circumferentially aligned. Rates of temperature change at each measuring point and average rate of temperature change of all measuring points are derived and compared for making judgement of possible break out when the difference of the rate of temperature change at each measuring point and the average rate of temperature change becomes greater than a predetermined value.

Abstract: In strip casting, a melt is pressed between a travelling belt and a casting drum rotating along with the belt. A method and device for measuring the speed difference between the speed of the belt and the peripheral speed of the drum involves providing the belt on one side with a pattern of alternately darker and lighter stripes. Around the periphery of the casting drum there is arranged a number of measuring zones, each having the same width as that of the stripes. Each measuring zone includes a transducer built up of a number of photocells which, via optical conductors opening out to the measuring zones, can be activated by the stripes. When, during a casting operation, a measuring zone has arrived at a given measuring region, the number of activated photocells is read. The same procedure is repeated when the same transducer arrives at the end of the measuring region.

Abstract: A method for determining level of molten metal in the input of a continuous metal casting machine having at least one endless, flexible, revolving casting belt with a surface which engages the molten metal to be cast and a reverse, cooled surface along which is directed high velocity liquid coolant includes the steps of predetermining the desired range of positions of the molten metal pool and positioning at least seven heat-sensing transducers in bearing contact with the moving reverse belt surface and spaced in upstream-downstream relationship relative to belt travel spanning the desired pool levels. A predetermined temperature threshold is set, somewhat above coolant temperature and the output signals of the transducer sensors are scanned regarding their output signals indicative of temperatures of the moving reverse belt surface.

Abstract: An apparatus and method for monitoring the liquid/solid interface position of an alloy ingot being formed by either direct chill or electromagnetically enhanced direct chill casting systems comprising an inductive sensor wire disposed about the mold wall of the casting system, driving the sensor wire to cause a magnetic flux to penetrate into the ingot, and sensing the change in the impedance or components of the impedance of the system. Monitoring the liquid/solid interface position allows ready adjustment to operating controls, such as, containment/stirring inductors, cooling systems and casting parameters, thereby producing a desirable ingot.

Abstract: In continuous metal-casting machines utilizing one or more thin flexible belts as mold surfaces, a suitably placed thermal sensing probe which contacts the reverse side of a casting belt results in enhanced control of molten-metal pool levels, in contrast to the earlier systems where a series of separately monitored probes were disposed serially against the belt from upstream to downstream, each of which registered a separately monitored "yes" or "no" signal. In accordance with the present invention, an intermediate temperature is selected as the control point, at one location in the mold. If the pool of molten metal rises above the optimum level, the sensing probe will register a correspondingly increased temperature. If the pool falls below optimum, the probe will register a cooler temperature. The resulting electrical signals are processed by an electronic circuit.

Abstract: A width changing method in which the width of a slab under casting is changed by a movement of narrow face of a continuous casting mold by the operation of a horizontal driving device and a rotary driving device operable independently of the horizontal driving device. The period of width changing operation is divided into a forward taper changing period in which each narrow face is inclined toward the center of the mold and a rearward taper changing period in which each mold wall is inclined away from the center of the mold. The acceleration of the horizontal movement of each narrow face is determined by means of allowable shell deformation resistance as a parameter for each period. Also is determined the angular velocity of the rotary device or the difference in velocity between the upper and lower ends of the narrow face. The width changing operation is conducted while maintaining the acceleration and the angular velocity or the velocity difference at constant levels in respective periods.

Abstract: Multiple castings are cut into billets, combined in a transverse transport facility, separate into billets to be inspected or not, recombined and cooled. Transportation includes two transverse facilities and two longitudinal facilities, combined in various combinations. The transportation is carried out with only one, or no, pivoting action and cooling is provided for alongside one of the multiple transport paths with overall accommodation to subsequent transport of billets out of the system.

Abstract: A load signal representing the load between a mold and an oscillating mechanism is separated into its static offset and dynamic components. The static offset signal is compared with a free-running static offset to obtain a substantially DC signal representing the DC component of mold friction. A DC voltage is generated corresponding to the RMS value of the dynamic load signal component, and a reference voltage corresponding to the RMS value of the dynamic signal component of a free-running load signal is subtracted in order to obtain a substantially DC signal representing the dynamic component of mold friction.

Abstract: For the purpose of monitoring the casting belts during operation of the caster to detect damage or faults to the casting belts, a plurality of ultrasonic testing units, which are stationary with respect to the direction of rotation of the casting belts and which are each designed as to transmit/receive unit, are associated with each casting belt.

Abstract: The abnormality is detected during a flow thereof through the mold. The detection is achieved by means of at least a pair of upper and lower temperature detecting elements, located along the flow of the casting metal. The abnormality is determined to exist when a temperature inversion, that is T.sub.U .ltoreq.T.sub.L, takes place. The symbols T.sub.U and T.sub.L denote the temperatures measured by the upper and lower temperature detecting elements, respectively, in which a relationship, that is T.sub.U >T.sub.L, stands under a normal casting operation.

Abstract: A breakout warning method and apparatus for a continuous casting installation wherein structure-bound sound, traveling through the area of the ingot mold, is continuously picked up by a sound recorder and checked for the presence of typical frictional noises between the mold and billet. A breakout signal is emitted upon determination that there are no typical frictional noises present.

Abstract: Apparatus and method is disclosed for on-line monitoring for early detection of diagonal distortion in a moving cast product ideally having a rectangular cross-section. A pair of contact rollers is supported on respective guide arms at a location along the casting path and biased to resiliently impinge on opposite edges of the moving cast product. A detector continuously senses the amount of separation between the contact elements to detect diagonal distortion in casting cross-section. A recorder is used to provide a tangible record of such variation. Optionally, both diagonals can be measured, and their sum or difference continuously monitored as well. A fixed support member carries the arms on slidable linear motion bearing structure to facilitate translational motion of the contact elements relative to the casting path, to minimize the effect of casting motion waver on contact separation.

Abstract: There is disclosed a method and arrangement for inspecting the surface of steel stock having a temperature above the Curie point. In order to detect, with a great certainty and accuracy, defects in the hot steel stock, with a loss of energy for cooling the steel stock for inspection and subsequently reheating it for further processing being avoided, only a thin surface layer of the steel stock is intensively cooled on the surface to be inspected, to a temperature below the Curie point. The core of the steel remains hot. Immediately thereafter, a magnetic or electromagnetic field is induced in the cooled surface layer and disturbances in the induced field caused by defects in the steel stock are detected and recorded by pick-ups.

Abstract: A method for detecting a molten metal surface level in a casting mold, comprises inserting an electrode in a slag constituting a layer under a flux floating on the surface of the molten metal, detecting a change of electric resistance due to a temperature gradient of the place at which the electrode is inserted, displacing the electrode to bring the detected value to be always constant within a range of from 5 to 50 .OMEGA., and measuring the degree of the displacement of the electrode thereby detecting the surface level of the molten level. An apparatus for carrying out the method is also disclosed.

Abstract: The level of a melt in a vertically reciprocating continuous-casting mold is detected by a method wherein a nonhomogeneous steady magnetic field is formed extending horizontally through the mold into the melt generally at the melt level. This field is vertically reciprocated jointly and synchronously with the mold and its field strength is detected at a sensing location after the field passes through the mold. This location is also vertically reciprocated jointly and synchronously with the mold. The melt level is derived from the detected field strength, normally taking into account melt conductivity and relative displacement rate of the mold and melt. With the use of a steady field the effect of the mold is automatically eliminated as the field does not move appreciably relative to the mold, so it generates virtually no eddy currents in it that would generate secondary fields.

Abstract: An apparatus and method for accurately and quickly adjusting the distance and tilt angle or taper between movable side wall mold plates in adjustable width continuous casting mold sections. A pair of spaced primary mold members with movable side wall mold plates therebetween, form an open ended mold cavity. Each side wall mold plate is connected to upper and lower fixed mold supports by separate upper and lower adjustable length connectors which have their inner ends hinged to the side wall mold plates. Each connector has an axial bore receiving a transducer core for reciprocating movement along a linear path. A cylindrical transducer coil housing in the bore, fixed relative to the mold cavity center, surrounds the movable core. The transducer core has one end anchored to a side wall mold plate.

Abstract: In order to be able to locate stuck rollers of a roller way as early as possible, with longer operational interruptions being avoided and the demounting of constructional parts of the roller way being not necessary, an arrangement for this purpose includes a supporting body which is movable along the roller way and carries a frictional head. The frictional head is pressable against the surface areas of subsequently arranged rollers. Means are provided for recording and measuring a difference between the velocity of the supporting body with which the latter is moved along the roller way and the velocity of the frictional head getting into contact with a roller.