Abstract: A sucker rod steel, a heat treatment process therefor, and a manufacturing method comprising the heat treatment process are provided. The sucker rod steel comprises, in mass percent, the following chemical elements: C: 0.10˜0.20%, Si: 0.40˜0.80%, Mn: 0.20˜0.60%, Mo: 0.36˜0.46%, Cr: 6.15˜7.10%, Al: 0.015˜0.035%, Nb: 0.02˜0.06%, and N: 0.008˜0.015%, with the balance being Fe and other inevitable impurities. The microstructure of the sucker rod steel is tempered martensite and nanoscale precipitates. The grain size is higher than grade 10, the tensile strength is 920˜1320 Mpa, and the AKU2 impact energy is greater than or equal to 180 J.

Abstract: Provided is a 600 MPa grade non-oriented electrical steel sheet with excellent magnetic properties, comprising the following chemical elements in mass percentage: 0<C?0.0035%; Si: 2.0-3.5%; Mn: 0.4-1.2%; P: 0.03-0.2%; Al: 0.4-2.0%; and the balance being Fe and unavoidable impurities. Also provided is a manufacturing method for the 600 MPa grade non-oriented electrical steel as described above, including the following steps: (1) converter smelting, RH refining and casting; (2) hot rolling; (3) normalizing; (4) cold rolling; (5) continuous annealing; and (6) applying an insulation coating to obtain a finished non-oriented electrical steel sheet.

Abstract: Disclosed is a high-magnetic-induction oriented silicon steel, wherein the chemical elements thereof are, in mass percentage: Si: 2.0-4.0%; C: 0.03-0.07%; Al: 0.015-0.035%; N: 0.003-0.010%; Nb: 0.0010-0.0500%, the balance being Fe and inevitable impurities. The manufacturing method for the high-magnetic-induction oriented silicon steel includes the steps of: (1) smelting and casting; (2) heating a slab; (3) hot rolling; (4) cold rolling; (5) decarbonizing and annealing; (6) nitriding treatment; (7) applying an MgO coating; (8) high temperature annealing; and (9) applying an insulating coating; wherein a high-magnetic-induction oriented silicon steel is obtained by the manufacturing method, having an average primary grain size of 14-22 ?m and a primary grain size variation coefficient of higher than 1.

Abstract: Disclosed is a method for manufacturing a cold-rolling strip steel (1) with the strength and hardness thereof varying in a thickness direction, the method comprising the steps: smelting, continuous casting, hot rolling, cold rolling, and continuous annealing. When quenching is performed in the continuous annealing step, an asymmetric quenching and cooling process is performed on both surfaces of the strip steel. In addition, also disclosed is a cold-rolling strip steel (1) with the strength and hardness thereof varying in a thickness direction, which is prepared by the above manufacturing method.

Abstract: Steel for coiled tubing with a low yield ratio and ultra-high strength and a preparation method thereof, wherein the chemical composition of the steel in mass percentage is: C: 0.05-0.16%, Si: 0.1-0.9%, Mn: 1.25-2.5%, P?0.015%, S?0.005%, Cr: 0.51-1.30%, Nb: 0.005-0.019%, V: 0.010-0.079%, Ti: 0.01-0.03%, Mo: 0.10-0.55%, Cu: 0.31-0.60%, Ni: 0.31-0.60%, Ca: 0.0010-0.0040%, Al: 0.01-0.05%, N?0.008%, and the rest being Fe and inevitable impurity elements. The chemical composition combines the technologies of low temperature finishing rolling and low temperature coiling to obtain an MA constituent+bainite+ferrite multiphase structure. The steel has a low yield ratio and ultra-high strength with the following specific properties: yield strength?620 MPa, tensile strength?750 MPa, elongation?11%, and yield ratio?0.83, and is suitable for manufacturing coiled tubing with ultra-high strength having a grade of 110 ksi or higher.

Abstract: A free-cutting and non-quenched and tempered steel, comprising the following chemical elements by mass percentages: C: 0.35-0.45%, Si: 0.45-0.0.65%, Mn: 1.35-1.65%, S: 0.025-0.065%, V: 0.07-0.15%, Ti: 0.01-0.018%, N: 0.012-0.017%, Al: 0.015-0.035%, Ca: 0.0008-0.0025%, with the remaining being iron and other unavoidable impurities, wherein the S and Ca elements satisfy the relationship S/Ca=20-60. A manufacturing method of the free-cutting and non-quenched and tempered steel, comprising the following steps: (1) smelting and refining; (2) casting; (3) rolling; (4) forging; and (5) two-stage cooling.

Abstract: There is provided a production method for on-line improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel, comprising: casting a molten steel with microalloying element Ti added to obtain an ingot; after heating the ingot, subjecting it to rough rolling, finish rolling, laminar cooling and coiling to obtain a hot-rolled coil; after unloading the coil, covering the coil on-line with an insulating enclosure and moving it into a steel coil warehouse along with a transport chain; after a specified period of on-line insulating time, removing the coil from the insulating enclosure, and cooling it to room temperature in air, wherein the microalloying element Ti has a content of ?0.03 wt %; the coiling is performed at a temperature of 500-700° C.; said covering on-line with an insulating enclosure means each hot-rolled coil is individually covered with an independent, closed insulating enclosure unit within 60 minutes after unloading; the on-line insulating time is ?60 minutes.

Abstract: The invention discloses a 780 MPa cold-rolled dual-phase strip steel having a microstructure of fine equiaxed ferrite matrix and martensite islands distributed homogeneously on the ferrite matrix, and comprising the following chemical elements in mass percentage: C: 0.06-0.1%; Si?0.28%; Mn: 1.8-2.3%; Cr: 0.1-0.4%; Mo: not added when Cr?0.3%; Mo=0.3—Cr when Cr<0.3%; Al: 0.015-0.05%; at least one of Nb and Ti elements, wherein Nb+Ti is in the range of 0.02-0.05%; and the balance amounts of Fe and other unavoidable impurities. Correspondingly, the invention also discloses a method for manufacturing the 780 MPa cold-rolled dual-phase strip steel. The 780 MPa cold-rolled dual-phase strip steel has high strength, superior elongation, good phosphating property and small anisotropy in mechanical properties.

Abstract: A hot dipped high manganese steel and a manufacturing method therefor. The high manganese steel comprises a steel base plate and a coating on the surface of the steel base plate. The core of the steel base plate is austenite. The surface layer of the steel base plate is a ferrite fine grain layer. The ferrite fine grain layer comprises an oxide of Al. Furthermore, the steel base plate of the hot dipped high manganese steel comprises, in mass percentages, 10 to 30% of Mn element, 1 to 2% of Al element, and 0.4 to 0.8% of C element. The manufacturing method comprises: 1) manufacturing strip steel; 2) primary annealing and acid washing; 3) secondary annealing and hot dipping.

Abstract: Disclosed are a non-oriented electrical steel sheet with excellent magnetic properties and a manufacturing method thereof, wherein the mass percentage of the chemical components thereof are: C: 0-0.005%; Si: 2.1-3.2%, Mn: 0.2-1.0%, P: 0-0.2%, Al: 0.2-1.6%, N: 0-0.005%, Ti: 0-0.005%, Cu: 0-0.2%, and the balance of Fe and inevitable impurities; and at the same time, (the S content for forming MnS+the S content for forming CuxS)/the S content in the steel is required to be less than or equal to 0.2. The process for manufacturing the non-oriented electrical steel sheet of the present invention is simple and convenient, the chemical components of the steel are easy to control, the manufacturing process is stable, and the technical requirements are easy to realize.

Abstract: A cold-rolled low-density steel sheet having excellent phosphorability is provided. An iron particle layer is disposed on the surface of the cold-rolled low-density steel sheet, and dispersed iron particles exist in the iron particle layer. The cold-rolled low-density steel sheet comprises 3.0% to 7.0% of element Al by mass percentage.

Abstract: Disclosed is a method for manufacturing an equal-strength steel thin-wall welding component with an aluminum or aluminum-alloy plating, wherein the plating comprises an intermetallic compound alloy layer in contact with the base body and a metal alloy layer on the intermetallic compound alloy layer; the plating is not removed or thinned before or during welding; and by presetting a welding gap and using a carbon-manganese-steel welding wire, a welding process and protective gas for welding, the tensile strength of a welding seam of the welding component after hot stamping processing is greater than the tensile strength of a base metal, and the elongation of a welded joint is greater than 4% Further disclosed are a welding wire for welding and an equal-strength steel thin-wall welding component with an aluminum or aluminum-alloy plating.

Abstract: An apparatus and a method for rapidly heating cold-rolled strip steel (10). The apparatus for rapidly heating cold-rolled strip steel (10) comprises a heating zone, a soaking zone, and a cooling zone, and the heating zone is sequentially divided into a first heating section (1), a second heating section (2), a third heating section (3), and a fourth heating section (4) along a moving direction of the strip steel (10) to be heated, the first heating section (1) and the fourth heating section (4) being radiant heating sections, and the second heating section (2) and the third heating section (3) being inductive heating sections. The method for rapidly heating cold-rolled strip steel (10) uses the apparatus for rapidly heating cold-rolled strip steel (10) to heat the strip steel (10).

Abstract: A laser-scribed grain-oriented silicon steel resistant to stress-relief annealing and a manufacturing method therefor. Parallel linear grooves (20) are formed on one or both sides of grain-oriented silicon steel (10) by laser etching. The linear grooves (20) are perpendicular to, or at an angle to, the rolling direction of the steel plate. A maximum height of edge protrusions of the linear grooves (20) does not exceed 5 ?m, and a maximum height of spatters in etch-free regions between adjacent linear grooves (20) does not exceed 5 ?m, and the proportion of an area occupied by spatters in the vicinity of the linear grooves (20) does not exceed 5%. The steel has low manufacturing costs, and the etching effect of the finished steel is retained during a stress-relief annealing process. The steel is suitable for manufacturing of wound iron core transformers.

Abstract: Disclosed is a different-strength steel welding component with an aluminum or aluminum-alloy plating formed by means of butt welding of a high-strength steel plate and a low-strength steel plate, and each of the high-strength steel plate and the low-strength steel plate comprises a base body and at least one pure aluminum or aluminum-alloy plating on a surface of the base body. The tensile strength of a welding seam of the welding component after hot stamping is greater than the tensile strength of a low-strength steel base metal, and the elongation is greater than 4%, such that application requirements of the welding component in the field of automobile hot stamping are met. The present disclosure also relates to a method for manufacturing a different-strength steel welding component with an aluminum or aluminum-alloy plating and a welding wire used in the method.

Abstract: A low-cost and high-formability 1180 MPa grade cold-rolled annealed dual-phase steel plate and a manufacturing method thereof are provided. The dual-phase steel plate has the following chemical composition by mass percentages: C: 0.1%-0.125%, Si: 0.4%-0.8%, Mn: 2.6%-2.9%, Al: 0.01%-0.05%, Nb: 0.01%-0.03%, and Ti: 0.01%-0.03%, the remainder being Fe and unavoidable impurities. By reasonable design of alloy elements and manufacturing processes, the dual-phase steel plate of the invention achieves a strength of 1180 MPa grade at a low cost, obtains a fine and uniform martensite-ferrite dual-phase structure that ensures excellent elongation rate and cold bending performance, and has good formability. The dual-phase steel plate has a yield strength of more than 850 MPa, a tensile strength of more than 1180 MPa, an elongation rate of 8% or more, and a parameter (R/t), characterizing the 90-degree cold bending performance, of 2.5 or less.

Abstract: Low-density hot dip galvanized steel, comprising a steel substrate (1) located at a core portion and a coating layer (3) located on the surface. An interface layer is disposed between the steel substrate (1) and the coating layer (3), the interface layer comprises an iron particle layer (4), iron particles dispersed on the steel substrate (1) and covering the steel substrate (1) are disposed in the iron particle layer (4), and the iron particles are covered by a first inhibition layer (5). The low-density hot dip galvanized steel contains element Al in a mass percentage of 3.0% to 7.0%. Correspondingly, the present invention also comprises a manufacturing method for the low-density hot dip galvanized steel. The low-density hot dip galvanized steel has a low density, a high strength and high galvanizability and coating layer adhesion.

Abstract: Disclosed are a high-strength and high-toughness steel plate with an 800 MPa grade tensile strength and a method for manufacturing the same, the chemical composition of the steel plate in weight percentage being: C: 0.15-0.25%, Si: 1.0-2.0%, Mn: 1.2-2.0%, P?0.015%, S?0.005%, Al: 0.5-1.0%, N: ?0.006%, Nb: 0.02-0.06%, O?0.003%, and the balance being Fe and other inevitable impurities, and 1.5%?Si+Al?2.5%. By adopting an isothermal heat treatment a high-strength and high-toughness steel plate with an 800 MPa grade tensile strength, which has a microstructure mainly including bainite ferrite and residual austenite, is obtained impact energy.

Abstract: A hot dipped medium manganese steel and a manufacturing method therefor. The medium manganese steel comprises a steel base plate and a coating on the surface of the steel base plate; the mass percentages of the components in the hot dipped medium manganese steel are: C: 0.1 to 0.3%, Si: 0.1 to 2.0%, Mn: 5 to 12%, Al: 1 to 2%, P?0.02%, S?0.02%, N?0.005%, and the remaining being Fe and unavoidable impurities; the core structure is ferrite and austenite, and the surface layer of the steel base plate is a ferrite layer.

Abstract: Disclosed are a continuous-curvature convex roll for continuously casting a bloom, and a manufacturing method therefore. An outer contour curve of a working portion of a body of the continuous-curvature convex roll contains a first straight-line segment (AB), a first transition curve segment (BC), an intermediate straight-line segment (CD), a second transition curve segment (DE) and a second straight-line segment (EF). The BC, the AB, and the CD have continuous first-order derivatives, continuous second-order derivatives, and continuous curvatures, thus forming a first transition curve with a continuous curvature. The BC and the DE are mirror-symmetrical. The continuous-curvature convex roll can uniformly deform a blank cast in a deformation area, thereby reducing cracks. The transition curve of the convex roll can be reduced, thereby being capable of further reducing a rolling pressure and the withdrawal resistance.