The present disclosure relates, according to some embodiments to a method for steel production, the method comprising forming a hydrogen and a carbon from a natural gas using thermal plasma electrolysis; reducing iron ore fines with the H.sub.2 to form an iron briquette; melting the briquette iron from the furnace to form a melted iron and melted non-metallic slag; separating the non-metallic slag from the melted iron in the furnace; combining the carbon and the melted iron in a furnace to form a carbon black and iron mixture; and alloying the melted iron with the carbon black to form a steel.

A high-grade non-oriented silicon steel and a production method are provided. The non-oriented silicon steel includes the following chemical components in percent by mass: 0.002-0.004% of C, not greater than 0.003% of S, 1.4-1.7% of Si, 0.7-0.95% of Mn, not greater than 0.03% of P, 0.015-0.035% of Sn; and 11×([Si]-1.4%)=14×([Mn]-0.7%). In the production method, the heating temperature of a continuous casting billet is 1,120-1,150° C.; the finishing temperature in finish rolling is 890±15° C.; the rolling reduction of the last pass of finish rolling is not less than 30%, the total rolling reduction of the last two passes of finish rolling is not less than 50%, and the coiling temperature is 650±20° C.; normalizing treatment is avoided before acid continuous rolling.

A high-grade non-oriented silicon steel and a production method are provided. The non-oriented silicon steel includes the following chemical components in percent by mass: 0.002-0.004% of C, not greater than 0.003% of S, 1.4-1.7% of Si, 0.7-0.95% of Mn, not greater than 0.03% of P, 0.015-0.035% of Sn; and 11×([Si]-1.4%)=14×([Mn]-0.7%). In the production method, the heating temperature of a continuous casting billet is 1,120-1,150° C.; the finishing temperature in finish rolling is 890±15° C.; the rolling reduction of the last pass of finish rolling is not less than 30%, the total rolling reduction of the last two passes of finish rolling is not less than 50%, and the coiling temperature is 650±20° C.; normalizing treatment is avoided before acid continuous rolling.

Disclosed are a 980 MPa-grade bainite high hole expansion steel and a manufacturing method therefor. The steel contains the following chemical components in percentages by weight: 0.05-0.10% of C, 0.5-2.0% of Si, 1.0-2.0% of Mn, P≤0.02%, S≤0.003%, 0.02-0.08% of Al, N≤0.004%, Mo≥0.1%, 0.01-0.05% of Ti, Cr≤0.5%, B≤0.002%, O≤0.0030%, and the balance of Fe and other inevitable impurities. The high hole expansion steel of the present invention has a yield strength of ≥800 MPa and a tensile strength of ≥980 MPa, has a good elongation rate (the transverse A.sub.50 being ≥11%) and hole expansion performance (the hole expansion ratio being ≥40%), and can be applied to a position on a chassis part of a passenger car, such as a control arm and a vice frame, where high strength and thinning are required.

Disclosed are a 980 MPa-grade bainite high hole expansion steel and a manufacturing method therefor. The steel contains the following chemical components in percentages by weight: 0.05-0.10% of C, 0.5-2.0% of Si, 1.0-2.0% of Mn, P≤0.02%, S≤0.003%, 0.02-0.08% of Al, N≤0.004%, Mo≥0.1%, 0.01-0.05% of Ti, Cr≤0.5%, B≤0.002%, O≤0.0030%, and the balance of Fe and other inevitable impurities. The high hole expansion steel of the present invention has a yield strength of ≥800 MPa and a tensile strength of ≥980 MPa, has a good elongation rate (the transverse A.sub.50 being ≥11%) and hole expansion performance (the hole expansion ratio being ≥40%), and can be applied to a position on a chassis part of a passenger car, such as a control arm and a vice frame, where high strength and thinning are required.

A low-carbon martensitic high hole expansion steel with a tensile strength above 980 MPa, and a manufacturing method therefor, the weight percentage of the chemical components thereof being: C 0.03-0.10%, Si 0.5-2.0%, Mn 1.0-2.0%, P≤0.02%, S≤0.003%, Al 0.02-0.08%, N≤0.004%, Mo 0.1-0.5%, Ti 0.01-0.05%, and O≤0.0030%, and the remainder being Fe and other inevitable impurities. The high hole expansion steel of the present invention has a yield strength of ≥800 MPa and tensile strength of ≥980 MPa, a lateral extension rate A50≥8%, and a hole expansion ratio of ≥30%, passes cold bending performance tests (d≤4a, 180°), and can be used for passenger car chassis parts that require high strength and thinning such as control arms and sub-frames.

A low-carbon martensitic high hole expansion steel with a tensile strength above 980 MPa, and a manufacturing method therefor, the weight percentage of the chemical components thereof being: C 0.03-0.10%, Si 0.5-2.0%, Mn 1.0-2.0%, P≤0.02%, S≤0.003%, Al 0.02-0.08%, N≤0.004%, Mo 0.1-0.5%, Ti 0.01-0.05%, and O≤0.0030%, and the remainder being Fe and other inevitable impurities. The high hole expansion steel of the present invention has a yield strength of ≥800 MPa and tensile strength of ≥980 MPa, a lateral extension rate A50≥8%, and a hole expansion ratio of ≥30%, passes cold bending performance tests (d≤4a, 180°), and can be used for passenger car chassis parts that require high strength and thinning such as control arms and sub-frames.

A control process of inclusions in ultra-clean rare earth steel, wherein the content of rare earth elements REM in the ultra-clean rare earth steel, the total oxygen content T[O]m, the total sulfur content T[S]m in the steel, and the total oxygen content T[O]r in a rare earth metal or alloy added to the steel are controlled to satisfy the following formula: −500<REM−(m*T[O]m+n*T[O]r+k*T[S]m)<−30, where REM is the content of rare earth elements in the steel, in ppm; T[O]m is the total oxygen content in the steel, in ppm; T[O]r is the total oxygen content in a rare earth metal or alloy added to the steel, in ppm; T[S]m is the total sulfur content in the steel, in ppm; m is a first correction coefficient, with a value of 2-4.5;n is a second correction coefficient; and k is a third correction coefficient.

A control process of inclusions in ultra-clean rare earth steel, wherein the content of rare earth elements REM in the ultra-clean rare earth steel, the total oxygen content T[O]m, the total sulfur content T[S]m in the steel, and the total oxygen content T[O]r in a rare earth metal or alloy added to the steel are controlled to satisfy the following formula: −500<REM−(m*T[O]m+n*T[O]r+k*T[S]m)<−30, where REM is the content of rare earth elements in the steel, in ppm; T[O]m is the total oxygen content in the steel, in ppm; T[O]r is the total oxygen content in a rare earth metal or alloy added to the steel, in ppm; T[S]m is the total sulfur content in the steel, in ppm; m is a first correction coefficient, with a value of 2-4.5;n is a second correction coefficient; and k is a third correction coefficient.

The present invention provides a non-magnetic stainless steel with high strength and corrosion resistance and a preparation method thereof. The non-magnetic stainless steel composed of the following components according to percentage by weight: 17%<Cr<23%, 17%<Mn<23%, 17%<Co<23%, 0.5%<Si <3%, and the balance of iron and inevitable impurities thereof. The preparation method includes: (1) melting a raw material and casting it to a mold to obtain a stainless steel block; (2) homogenizing the stainless steel block at 1,100-1,250° C. for 6-12 hours; (3) forging the homogenized stainless steel block at 1,050-1,150° C. with a final forging temperature of 850-950° C. to obtain a plate having a thickness of 5-15 mm; and (4) holding the forged plate at 1,000-1,250° C. for 10-30 minutes and then put it in water for quenching. The non-magnetic stainless steel of the present invention has superior pitting corrosion resistance and mechanical properties. After a certain heat treatment process, the stainless steel has ultrahigh strength, hardness and toughness and excellent corrosion resistance and low-temperature toughness, and can be used for preparing an outer cladding material of a superconductor in the nuclear fusion industry.