摘要:
In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by a fluorescent X-ray analysis method using an energy dispersion type spectroscope, or by other chemical or physical measurements, to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.
摘要:
In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by a fluorescent X-ray analysis method using an energy dispersion type spectroscope, or by other chemical or physical measurements, to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.
摘要:
In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by dissolving the surface and extracting and filtering the inclusions to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.
摘要:
A rapid analysis device for analyzing nonmetallic inclusions in steel by a cold crucible method is combined with a mathematical model, and the quality of cast steel is predicted online by simulating the behavior. of the nonmetallic inclusions by calculation. Further, continuous casting process variables are controlled to minimize the amount of nonmetallic inclusions in the cast steel.
摘要:
The present invention provides a method, for regulating the flow of a molten steel within a mold by taking advantage of a direct current magnetic field, comprising the step of carrying out continuous casting while regulating the flow of a molten steel, delivered through a nozzle, by applying a direct current magnetic field having a substantially uniform magnetic flux distribution over the whole width direction of the mold, characterized in that the flow velocity of a meniscus on the surface of the molten steel within the mold is regulated in a range of from 0.20 to 0.40 m/sec by regulating the molten steel delivery angle of the nozzle, the position of the magnetic field, and the magnetic flux density. When the flow velocity of the meniscus is greatly increased, a stream of the molten steel delivered through the nozzle is allowed to collide directly with a short-side wall of the mold and, thereafter, the flow velocity is regulated according to the following equation (1), while, when the flow velocity of the meniscus is increased or decreased, a stream of the molten steel delivered through the nozzle is allowed to traverse a magnetic field zone and then to collide with a short-side wall of the mold and, thereafter, the flow velocity is regulated according to the following equation (2):V.sub.P /V.sub.O =1+.alpha..sub.1 {1-exp(-.beta..sub.1 .multidot.H.sup.2)}(1)V.sub.P /V.sub.O =1+.alpha..sub.2 {sin (.beta..sub.2 .multidot.H)exp(-r.multidot.H)} (2)wherein H=185.8.multidot.B.sup.2 .multidot.D.multidot.T/(D+T)V.
摘要:
The present invention provides a continuous casting method in which vibration is given to molten metal by a shifting magnetic field so that the equi-axed crystal ratio can be enhanced and the equi-axed crystals can be made fine without generating surface defects caused by powder trapping. Further, the present invention provides an apparatus to which the continuous casting method is applied. Furthermore the present invention provides a cast slab produced by the above method and apparatus. The method of casting molten metal comprises the following steps: pouring molten metal into a mold and solidifying it in the mold while applying an electromagnetic force, which is generated by an electromagnetic coil arranged in the proximity of a molten metal pool in the mold, upon the molten metal; and vibrating the molten metal, which has been solidified in the mold while being cooled and solidified, by a shifting magnetic field generated by the electromagnetic coil so that the molten metal is accelerated by a high intensity and a low intensity of acceleration in a range not exceeding a predetermined flow velocity when the directional vectors of high acceleration and low acceleration in the same direction or in the opposite direction are combined with each other.
摘要:
An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefor, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.
摘要:
A cast slab has a negative segregation zone composed of a multilayer structure of negative segregation layers disposed between dendrite or crystalline layers. The dendrite or crystalline layers are a deflection structure caused by vibration during formation of the cast slab. The negative segregation layers have a distance between them of not more than 2 mm and the number of negative segregation layers is not less than 3. The cast slab has an equi-axed crystal ratio of not less than 50% inside the multilayer negative segregation zone.
摘要:
An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefore, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.
摘要:
(Object) IF-based, continuously cast slab essentially freed from defects such as surface defects, difficult production and poor strength, etc. of the product that the IF-based sheet steels have; sheet steels and a process for producing the same are provided.(Structure) A continuously cast slab of extremely low carbon steel comprising not more than 1.5% by mass of Si, not more than 2.0% by mass of Mn, not ore than 0.15% by mass of P, 0.01-0.15% by mass of Al, and not more than 0.0050% by mass of N, where the surface layer further contains 0.01-0.08% by mass of C existing as a cementite and the inner layer further contains not more than 0.0050% by mass of C, and at least one of 0.02-0.10% by mass of Ti, 0.01-0.10% by mass of Nb, 0.02-0.10% by mass of V and 0.03-0.10% by mass of Zr, the carbon existing substantially as carbides of these elements, preferably both the surface layer and the inner layer further contain 0.0001-0.0015% by mass of B, the balance being Fe and inevitable impurities; an sheet steel made from the slab; and a process for producing the slab and the sheet steel, combined with continuously casting powder, an electromagnetic brake and an alloy-adding wire.(Effect) The IF steel and its high strong steel, which have been suffered from impaired mass production, lower production yield and incomplete product characteristics have been established as satisfactory basis metallic materials.