A steel for induction hardening according to the present invention includes a chemical composition consisting of, in mass percent: C: 0.58 to 0.68%, Si: 0.70 to 1.40%, Mn: 0.20 to 1.40%, P: less than 0.020%, S: less than 0.020%, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, O: 0.0015% or less, V: 0.01 to 0.25%, B: 0.0003 to 0.0040%, Ti: 0.010 to 0.050%, and Ca: 0.0005 to 0.005%, with the balance being Fe and impurities, and satisfies Formulae (1) to (3). The steel microstructure is made up of ferrite and pearlite. A ratio of a number of composite inclusions is 20% or more.
C+Si/7+Mn/5+Cr/9+Mo/2.51.05(1)
C+Si/10+Mn/20+Cr/250.70(2)
Cr/Si0.20(3)

A non-oriented silicon steel and a production method are provided. The non-oriented silicon steel is prepared by using the processes of molten iron desulfurization, converter smelting, RH refining, continuous casting, hot rolling, acid tandem rolling, annealing, coating and finishing, and a chemical composition is as follows in mass percent: C0.003%, S0.008%, Si: 0.35%+1, Mn: 0.15-0.25%, P: 0.04-0.06%, Sn: 0.015%+2, Nb0.004%, V0.004%, Ti0.005%, Mo0.004%, Cr0.03%, Ni0.03%, Cu0.03%, N0.003% and the balance of Fe and inevitable inclusions. The non-oriented silicon steel has the iron loss P.sub.1.5/505.5 W/kg and the magnetic induction intensity B.sub.50001.75 when having the thickness of 0.5 mm, and desulfurization is not needed in the RH refining process.

A production method for smelting clean steel from full-scrap steel using duplex electric arc furnaces. Electric arc furnaces located in two positions are connected in series, wherein the electric arc furnace in a first position is dephosphorization electric arc furnace, and the electric arc furnace in a second position is a decarbonization electric arc furnace. The production method includes: performing smelting by combining a decarbonization electric arc furnace and 1-3 dephosphorization electric arc furnaces; a specific process of performing the smelting includes: in a charging period of the 1-3 dephosphorization electric arc furnaces, adding the full-scrap steel for the smelting, lime, slag in the decarbonization electric arc furnace, auxiliary materials and carbon powder or a carbon block into the dephosphorization electric arc furnace.

A molten steel refining method includes throwing a powder to molten steel while heating the powder with a flame formed by combustion of a hydrocarbon gas at the leading end of a top blowing lance. The lance height of the top blowing lance (the distance between the static bath surface of the molten steel and the leading end of the lance) is controlled to 1.0 to 7.0 m, and the dynamic pressure P of a jet flow ejected from the top blowing lance calculated from equation (1) below is controlled to 20.0 kPa or more and 100.0 kPa or less. P=.sub.g U.sup.2/2 . . . (1) wherein P is the dynamic pressure (kPa) of the jet flow at an exit of the top blowing lance, .sub.g the density (kg/Nm.sup.3) of the jet flow, and U the velocity (m/sec) of the jet flow at the exit of the top blowing lance.

A melting pot includes a pot body and a float salvaging apparatus. The pot body is provided with a melting chamber having an open upper end. The float salvaging apparatus includes a hanging bracket, a bearing plate, a rotating plate and a drive assembly configured to drive pivoting of the rotating plate. The hanging bracket is disposed above the melting chamber. The rotating plate is pivotably disposed on the bearing plate, and the bearing plate and the rotating plate are provided on the hanging bracket between an initial position and a first salvaging position in a manner of moving up and down. The drive assembly is connected to the rotating plate.

An R, R, C method and equipment for continuously casting amorphous, ultra-microcrystalline, microcrystalline and the like, metal profiles is provided. A working chamber of an exhaust hood with a powerful exhaust hood, and a working cold source of liquid nitrogen at a temperature of t=190 C. and a pressure of p=1.877 bar are used. The working chamber of exhaust hood is located at the outlet of hot mold, and only air is contained therein in addition to slabs or profiles that are pulled out, without any device or equipment. A traction mechanism pulls metal slabs or profiles out from the outlet of cross section of hot mold. A liquid nitrogen ejector ejects liquid nitrogen to the metal slabs or profiles of different brands and specifications at a liquid nitrogen ejection volume of liquid nitrogen V, an ejection speed of liquid nitrogen K and a thickness of liquid nitrogen ejection layer h.

An R, R, C method and equipment for continuously casting amorphous, ultra-microcrystalline, microcrystalline and the like, metal profiles is provided. A working chamber of an exhaust hood with a powerful exhaust hood, and a working cold source of liquid nitrogen at a temperature of t=190 C. and a pressure of p=1.877 bar are used. The working chamber of exhaust hood is located at the outlet of hot mold, and only air is contained therein in addition to slabs or profiles that are pulled out, without any device or equipment. A traction mechanism pulls metal slabs or profiles out from the outlet of cross section of hot mold. A liquid nitrogen ejector ejects liquid nitrogen to the metal slabs or profiles of different brands and specifications at a liquid nitrogen ejection volume of liquid nitrogen V, an ejection speed of liquid nitrogen K and a thickness of liquid nitrogen ejection layer h.

Systems, methods, and apparatus for treating a molten metal are provided. A metal treatment system, comprising: a wire feeding subsystem; and a cored wire; wherein the wire feeding subsystem feeds the cored wire into a metal bath at a controlled wire feed rate, and wherein the metal bath comprises a molten metal; wherein the cored wire comprises: a consumable outer sheath having a tubular cross section; and a core fill material coupled to an inner surface of the outer sheath, wherein the core fill material comprises a refining agent for refining the molten metal; and wherein the refining agent reacts with the molten metal, thereby causing an impurity to be removable from the metal bath.

A method that, regarding a process of refining molten iron, can increase the thermal margin and the amount of cold iron source to be used. A burner having jetting holes for jetting a fuel and a combustion supporting gas is provided at a leading end part of one lance that top-blows an oxidizing gas to molten iron contained in a converter-type vessel, or at a leading end part of another separate lance. A powdery auxiliary raw material or an auxiliary raw material processed into a powder form that is blown into the molten iron from the one lance or the other lance passes through a flame formed by the burner. This top-blowing lance for a converter is configured to secure a predetermined heating time and powder-fuel ratio. Also, a method for adding an auxiliary raw material and a method for refining of molten iron that use this top-blowing lance.

The present invention discloses a 400 MPa corrosion-resistant steel bar and a production method thereof. The steel bar includes the following chemical ingredients: 9.5-10.4% of Cr, 1.0-1.2% of Mo, 0.3-0.6% of Mn, 0.01-1% of Ni, 0.01-0.5% of Cu, at most 0.014% of C, at most 0.004% of N, 0.01-0.05% of Nb, 0.2-0.6% of Si, and the balance of Fe, where Cr+Mo+0.5Mn+0.35Ni+0.25Cu is 11.1-12.2%, and C+N+0.3Si+Mn+1.8Nb is 0.4-0.8%.