A process for smelting steel for ultrafine carborundum sawing wires, comprising: 1) in a vacuum induction furnace, using pure iron and low-phosphorus pig iron as raw materials to be melted into molten steel under the protection of argon; vacuumizing and smelting, and degassing; using silicon iron as a deoxidizer to adjust components of the molten steel; and casting a circular ingot in vacuum; 2) cleaning the surface of the circular ingot to produce an electrode bar; 3) remelting and smelting the electrode bar as raw material to a cylindrical electroslag ingot in an electroslag furnace, wherein the electroslag protecting slag comprises: CaF.sub.2: 45-55%, Al.sub.2O.sub.3: 15-25%, SiO.sub.2: 20-25%, Na.sub.2O: 2-4%, and K.sub.2O: 1-2%; 4) forging the electroslag ingot to a square billet; and 5) rolling the forged billet to a steel wire rod, and the steel wire rod comprising [C]: 0.92-1.1%, [Si]: 0.3-0.4%, [Mn]: 0.5-0.8%, [Al]<0.0008%, [N]<0.005%, [S]<0.01%, and [P]<0.015%.

The invention discloses a method for preparing a stainless steel seamless tube with ultra-high cleanliness for an integrated circuit and an IC industry preparation device, and a stainless steel seamless tube with ultra-high cleanliness. The stainless steel seamless tube which comprises, by mass, C≤0.010%, P≤0.020%, S≤0.010%, Mn≤0.10%, Si≤0.30%, Se≤0.010%, Al≤0.010%, Cu≤0.20%, Cr16.50-17.00%, Ni14.50-15.00%, Mo2.20-2.50%, N≤0.010%, Ni≤0.010%, Ti≤0.010% and the balance Fe and impurities is prepared through a: a stainless steel refining process; b: a vacuum induction melting and vacuum consumable remelting process; c: a stainless steel forging process; d: a hot piercing process; e: a cold working process; f: an inner bore electrolytic polishing, pickling and passivation process; and g: a cleaning process. The stainless steel seamless tube with ultra-high cleanliness prepared through these processes meet the requirements for ultra-high cleanliness and high performance of 316L stainless steel tubes for a semiconductor preparation device.

An NPR non-magnetic steel material for rock bolt and a production method thereof are disclosed. The NPR non-magnetic steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, MN: 15-20%, Cr: 1-18%, Si: 0.3-3%, Ca: 0.05-0.15%, Cu: ≤0.03%, Ni: ≤0.02%, S: ≤0.001%, P: ≤0.001%, and the rest being Fe and unavoidable impurity elements. The NPR non-magnetic steel material for rock bolt and the production method thereof effectively solve the problems of steel materials for rock bolt in the prior art such as strong magnetism, low tensile strength and low effective elongation. The NPR non-magnetic steel material for rock bolt has a fully-austenitized structure and is non-magnetic, its yield strength is adjustable in the range of 600-1000 MPa, and its elongation is adjustable in the range of 20-60%.

An NPR non-magnetic steel material for rock bolt and a production method thereof are disclosed. The NPR non-magnetic steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, Mn: 15-20%, Cr: 1-18%, Si: 0.3-3%, Ca: 0.05-0.15%, Cu: ≤0.03%, Ni: ≤0.02%, S: ≤0.001%, P: ≤0.001%, and the rest being Fe and unavoidable impurity elements. The NPR non-magnetic steel material for rock bolt and the production method thereof effectively solve the problems of steel materials for rock bolt in the prior art such as strong magnetism, low tensile strength and low effective elongation. The NPR non-magnetic steel material for rock bolt has a fully-austenitized structure and is non-magnetic, its yield strength is adjustable in the range of 600-1000 MPa, and its elongation is adjustable in the range of 20-60%.

When storing a molten ferroalloy or molten nonferrous metal, the molten ferroalloy or molten nonferrous metal is denitrified or prevented from absorbing nitrogen, and thus post processing such as a denitrification process may not be performed. For this, there is provided a method of producing molten manganese-containing steel, the method including: preparing a molten ferroalloy or a molten nonferrous metal; maintaining the molten ferroalloy or the molten nonferrous metal at a temperature equal to or higher than a melting point thereof; and pouring the molten ferroalloy or the molten nonferrous metal into prepared molten steel, wherein in the maintaining of the molten ferroalloy or the molten nonferrous metal, the molten ferroalloy or the molten nonferrous metal is subjected to a nitrogen-absorption prevention process or a denitrification process.

A smelting vessel (4) for producing molten metal includes a refractory lined hearth that in use is in contact with molten slag or molten metal in the smelting vessel, and the hearth includes a plurality of heat pipes (2.1) positioned in a refractory lining of at least a part of the hearth for cooling the refractory lining.

A process for the production of steel powders including the steps of: providing molten iron from a blast furnace, refining the molten iron in a converter to form molten steel including up to 600 ppm C, up to 120 ppm S, up to 125 ppm P, up to 50 ppm N and up to 1200 ppm O, pouring the molten steel in a plurality of induction furnaces, adding, in each of the plurality of induction furnaces, at least one ferroalloy to adjust the steel composition, pouring the molten steel at the desired composition of each induction furnace in a dedicated reservoir connected to at least one gas atomizer, feeding the at least one gas atomizer of each reservoir in molten steel from each reservoir under pressure and gas atomizing the molten steel to form the steel powder at the desired composition.

Plant for melting metal materials comprising at least a heating unit (11) provided with a container (13) to contain the mainly metal materials and with at least an induction heating device (22) configured to heat the mainly metal materials contained in the container (13). The plant also comprises a transfer unit (25) disposed downstream of the heating unit (11) and configured to move, substantially continuously, the mainly metal solid materials exiting from the heating unit (11) to a melting furnace (12). The container (13) is provided with an aperture (16) through which the mainly metal material, heated and in a solid state, is discharged onto the transfer unit (25), and opening/closing members (17) are associated with the aperture (16), commanded by an actuator (19) and configured to open, close and choke the aperture (16) in order to regulate the delivery of the metal materials that is discharged onto the transfer unit (25).

An electromagnetic induction furnace which is intended to melt at least one electrically conductive material, such as an oxide and/or a metal, and which includes at least one inductor having at least one turn and at least one cooling circuit suitable for cooling at least the inductor. Said furnace is characterized in that the heat-transfer fluid of at least one cooling circuit is supercritical CO2. The invention also relates to a method for operating the furnace and to the use thereof for melting a mixture of metals (steel, zirconium, etc.) with oxides (uranium UO2, zirconium, etc.), as well as concrete components, the mixture representing a corium.

The present invention relates to a system for contactless induction of high-frequency vibrations in a volume of molten metal during the manufacturing of a metal component or a metal matrix composite component. The system includes a moveably arranged electromagnetic primary coil, adjustment means for adjusting the position of the primary coil, and a control unit for controlling the position of the primary coil to a predefined distance above, but not in contact with, an upper free surface of the molten metal. The molten metal may be contained in a foundry crucible during manufacturing. The system can be used as an additive manufacturing system, with the primary coil arranged above the melt pool. A secondary low-frequency electromagnetic coil may be arranged around and at a distance from the molten metal to induce flow and/or vibrations in the molten metal.