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 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.

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%.

A process for manufacturing an iron-based alloy comprising forming targeted fine oxide and/or carbide dispersoids in a melt, and sequentially precipitating transition-metal nitrides on the dispersoids for heterogeneous nucleation of equiaxed grains. An iron-based cast alloy having a highly equiaxed fine grain structure.

A method for smelting low-phosphorus high-manganese steel based on reduction dephosphorization of ferromanganese is provided in the present application, relating to the technical field of high-manganese steel smelting, where the dephosphorization of ferromanganese is carried out under reducing atmosphere conditions through mediate-frequency induction furnace to obtain molten ferromanganese with lower phosphorus content, which is subsequently mixed with low phosphorus molten steel obtained by smelting in oxidative period of electric arc furnace in LF ladle refining furnace to make the Mn content of steel reach the requirement of high-manganese steel, and smelting is carried out under the condition of reducing atmosphere by adjusting the composition and temperature of the molten steel to meet the requirements of the target composition of the steel grade before tapping the steel.

An unoriented silicon steel having high magnetic conductivity and low iron loss at a working magnetic density of 1.0-1.5 T and method for manufacturing same. By proper deoxidation control in a RH refining and high-temperature treatment for a short time in a normalizing step, the method can reduce the amount of inclusions in the silicon steel and improve grain shape, so as to improve the magnetic conductivity and iron loss of the unoriented silicon steel at a magnetic density of 1.0-1.5 T.

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.

A process for smelting high-speed steel by using an intermediate frequency furnace-LF furnace-VD includes: firstly, melting a steel material in an intermediate frequency furnace, smelting until the steel material is melted, adjusting chemical components, and then performing deoxidation and slagging; performing electric heating for steel tapping, sending the steel tapping into an LF furnace for smelting, heating to 1470-1510? C., and adjusting the chemical components; and finally, sending these components into a VD furnace for vacuum treatment, and performing steel tapping after the components are qualified. A slagging process in the intermediate frequency furnace is used, then the coarse adjustment of chemical components, the primary deoxidation, and the slagging are performed in the intermediate frequency furnace. After the molten steel is sent to the LF furnace, the slag adjustment can be performed. A content of oxygen in the molten steel can be controlled within 10 ppm after the VD vacuum treatment.

A spring steel includes a predetermined chemical composition and a composite inclusion having a maximum diameter of 2 m or more that TiN is adhered to an inclusion containing REM, O and Al, in which the number of the composite inclusion is 0.004 pieces/mm.sup.2 to 10 pieces/mm.sup.2, the maximum diameter of the composite inclusion is 40 m or less, the sum of the number density of an alumina cluster having the maximum diameter of 10 m or more, MnS having the maximum diameter of 10 m or more and TiN having the maximum diameter of 1 m to 10 pieces/mm.sup.2.

There is a hot-rolled steel according to one aspect of the invention including predetermined chemical compositions including 0.0001 to 0.0050 mass % of Bi, in which 90 area % or more of a metallographic structure is configured with a ferrite and a pearlite, and an average number density of Mn sulfides extending along a rolling direction and having an aspect ratio exceeding 10 and equal to or smaller than 30, which is measured on a cross section parallel to the rolling direction, is 50 to 200 number/mm.sup.2.