Abstract: The present invention is a measuring method for detecting penetrant metal intruded in refractories having a conductive cover at a first wall and a nonconductive surface at a second wall and for measuring their thickness. At least one sensor head is used including a metal sensor with a first and second conductive coil for measuring distance between the sensor head and a conductive substance and a distance sensor for measuring distance between the sensor head and the refractories. The sensor head is disposed at a plurality of fixed positions close to the second wall to face the refractories and an alternating current is applied to the first coil to generate an eddy current in the conductive substance which faces the metal sensor. An induced voltage induced in the second coil by at least the eddy current is detected and a first distance is obtained between the sensor head and the conductive substance based on the detected induced voltage.

Abstract: The present invention relates to a refractory for casting process composed mainly of 0.3 to 10 wt % light burned magnesia, 3 to 30 wt % micro fine calcined alumina, and the remainder of either sintered alumina, fused alumina and MgO-Al.sub.2 O.sub.3 spinel or sintered alumina and MgO-Al.sub.2 O.sub.3 spinel or fused alumina and MgO-Al.sub.2 O.sub.3 spinel.

Abstract: An injection apparatus for a high-speed type thin plate continuous casting machine comprises linear motors (3A, 3B) interposing long sides of a flat nozzle (3), a power source unit for applying predetermined currents having a predetermined frequency to the linear motors (3A, 3B), and linear motor power factor improving capacitors (21) connected between the linear motors (3A, 3B) and the power source unit. A material on the inner walls of the short sides of the flat nozzle (3) is a conductive material to improve an edge effect, additionally, the apparatus is constructed to use a heating operation of the linear motor in heating the nozzle or a molten metal in the nozzle by adequately controlling a frequency or a current of a power supplied to the linear motors.

Abstract: A gas-blow casting nozzle has an annular gas-blowing hollow chamber with a gas-permeable part which is provided between the hollow chamber and the pouring hole of the nozzle body, and a number of joint parts for integrally joining the inner wall and the outer wall of the hollow chamber, which are provided in the radial direction of the annular hollow chamber. The total of the vertical section of the cylindrical area of the joint parts is about 30% to 70% of the cylindrical area of the hollow chamber. The gas-blowing hollow chamber which has the function of a heat-insulating layer is so constructed that the inner wall and the outer wall of the hollow chamber are partially and uniformly joined with the joint parts, and the joint parts are made to have the function of a heat-transfering layer, whereby the temperature difference in the radial direction of the nozzle body may be made small and the occurrence of thermal stress in the casting nozzle may be prevented.