A hot-rolled automobile steel having good surface and fatigue performance. The hot-rolled automobile steel comprises the following components in percentages by weight: C: 0.03-0.065%, Mn: 1.2-1.8%, P≤0.013%, S≤0.003%, Al: 0.25-0.45%, Ti: 0.11-0.18%, Cr: 0.1-0.5%, Nb: 0.02-0.05%, and N: 0.001-0.005%. The production method therefor comprises: 1) performing a vacuum treatment after converter smelting; heating a casting blank; performing rough rolling and ultrahigh pressure descaling; performing finish rolling; performing ultra-high pressure water descaling after finish rolling; performing cooling; and performing coiling. The hot-rolled automobile steel not only has a yield strength of larger than or equal to 750 MPa, a tensile strength of 800-950 MPa, and an elongation of larger than or equal to 16%, and does not crack when the cold bending radius is half of the thickness and a cold bending angle is 180 degrees, but also has a surface roughness of smaller than or equal to 1.5, a microhardness HV0.025 at the position having a depth of 30 μm to the surface layer of larger than or equal to 230, and the symmetric fatigue limit of a steel plate in a state of having oxide scales is larger than or equal to 330 MPa.
A quenching production line, comprising a shot blasting machine (4), a heating furnace (3), and a quenching machine (1) which are sequentially arranged along a quenching center line. A slotted nozzle cooling section (1.1), a circular high-pressure nozzle cooling section (1.2), and a high-pressure spraying pipe cooling section (1.3) are sequentially arranged in the quenching machine (1) along the running direction of a steel plate (2); the slotted nozzle cooling section (1.1) and the circular high-pressure nozzle cooling section (1.2) each are divided into a plurality of cooling control areas along the width direction of the steel plate (2) and the upper and lower surfaces of the steel plate (2); and the flow of cooling water in the cooling control areas is independently adjustable. The quenching machine (1) having the plurality of cooling control areas in which the flow of the cooling water is independently adjustable is used, and on the basis of water flow characteristics of the upper and lower surfaces of the steel plate (2) in the cooling process and stress problems caused by thermal stress and tissue phase change borne by the steel plate (2) in different cooling areas, parameters of different cooling control areas are set, thereby effectively controlling the plate shape in the quenching process, so that the plate shape of the steel plate (2) can be improved.
IIIIIIIIIIIIIIIIIII|≤20°C. In the present invention, the side surface bending is ≤ 0.8 mm/m after the steel rail exits the heat treatment unit, which effectively avoids the situation where the side surface of the steel rail is seriously bent, such that the steel rail cannot normally travel by means of a roller bed or will impact a side baffle of the roller bed.
5050 is greater than or equal to 1.60 T, so that the requirement of a pumped storage hydro-generator rotor having a rated rotation speed of 600 r/min for a 750 Mpa-grade ultra-thin magnetic yoke steel can be completely satisfied.
C22C 38/02 - Ferrous alloys, e.g. steel alloys containing silicon
C22C 38/04 - Ferrous alloys, e.g. steel alloys containing manganese
C22C 38/18 - Ferrous alloys, e.g. steel alloys containing chromium
C22C 38/24 - Ferrous alloys, e.g. steel alloys containing chromium with vanadium
C22C 38/32 - Ferrous alloys, e.g. steel alloys containing chromium with boron
C22C 38/06 - Ferrous alloys, e.g. steel alloys containing aluminium
C21D 8/12 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
Disclosed in the present invention is a 400 MPa-grade coating-free hot-rolled wire rod and round rod, which comprises the following chemical components in percentages by mass: C: 0.02-0.10 wt%, Si <0.25 wt%, Mn <0.4 wt%, P<0.03 wt%, S<0.02 wt%, Cu: 0.1-1.0 wt%, Cr: 1.0-4.5 wt%, with Cr/Cu ＝ 5-11, and the balance of Fe and inevitable impurities. The wire rod and the round rod can also undergo the process of microalloying, and further comprise the following chemical components in percentages by mass: Nb: 0.015-0.035 wt%, V: 0.04-0.07 wt%, and Nb/V = 1/3 to 2/3. The 400 MPa-grade coating-free hot-rolled wire rod and round rod and a rolling process therefor provided in the present invention satisfy the coating-free direct naked use requirements and the maintenance-free requirements of the whole life cycle of downstream users, thereby greatly reducing the production and investment cost; in addition, by means of rational component design and matching with a steel rolling process in the present invention, the steel has good strength and toughness, can satisfy various cold machining requirements of a hot-rolled wire rod and round rod, and the use scenarios of a weathering steel are greatly expanded.
C22C 38/02 - Ferrous alloys, e.g. steel alloys containing silicon
C22C 38/04 - Ferrous alloys, e.g. steel alloys containing manganese
C22C 38/20 - Ferrous alloys, e.g. steel alloys containing chromium with copper
C21D 8/06 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
B21B 1/16 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-sectionSequence of operations in milling trainsLayout of rolling-mill plant, e.g. grouping of standsSuccession of passes or of sectional pass alternations for rolling wire or material of like small cross-section
Disclosed is a hot-rolled wire rod for a weather-resistant steel strand at over 1300 MPa, comprising the following chemical components in percentage by mass: C: <0.12 wt%, Si: 0.1-1.2 wt%, Mn: <0.8 wt%, P<0.02 wt%, S<0.02 wt%, Cu: 0.1-1.0 wt%, Cr: 1.0-4.0 wt%, Cr/Cu=8-12, and the balance being Fe and unavoidable impurities. Microalloying may be carried out according to requirements, further adding in the chemical components in percentage by mass: Nb: 0.015-0.035 wt%, V: 0.04-0.07 wt%, Nb/V=1/3-2/3. The present invention provides a hot-rolled wire rod for weather-resistant steel strand at over 1300 MPa and a rolling process therefor, and by means of an innovative chemical composition system and providing a suitable organizational control process, the present invention can achieve steel wire strands without coating or plating for bare use, significantly reducing downstream user procurement costs, and facilitating the implementation of the goals of "carbon peaking and carbon neutrality" in the field of steel wire strands.
C22C 38/02 - Ferrous alloys, e.g. steel alloys containing silicon
C22C 38/04 - Ferrous alloys, e.g. steel alloys containing manganese
C22C 38/20 - Ferrous alloys, e.g. steel alloys containing chromium with copper
B21B 1/16 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-sectionSequence of operations in milling trainsLayout of rolling-mill plant, e.g. grouping of standsSuccession of passes or of sectional pass alternations for rolling wire or material of like small cross-section
C21D 8/06 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
7.
ECONOMICAL HYDROGEN GAS CONVEYING PIPELINE STEEL, AND PRODUCTION METHOD
The economical hydrogen gas conveying pipeline steel, which comprises the following components in wt%: C: 0.03-0.08%, Si: ≤ 0.15%, Mn: 0.53-1.19%, P: ≤ 0.012%, S: ≤ 0.0015%, Ti: 0.010-0.080%, Al: 0.025-0.048%, N: ≤ 0.0045%, and O: ≤ 0.002%. The method comprises: smelting then casting to form a blank; heating the casted blank; rough rolling; finishing rolling; cooling; and coiling. The yield strength of the present invention is 298-507 MPa, heat treatment is not needed, production and manufacturing processes are shortened, and overall energy consumption is reduced.
The present invention discloses a rolling contact fatigue resistant steel rail for a mixed passenger and freight railway, characterized by comprising the following chemical components by weight percentage: 0.75-0.88% C, 0.10-0.60% Si, 0.75-1.30% Mn, 0.20-0.55% Ni, 0.10-0.20% V, 0.03-0.06% Nb, less than or equal to 0.025% P, less than or equal to 0.025% S, and the remainder being Fe and inevitable impurities. The production process comprises the following steps: molten iron desulfurization, converter smelting, LF refining, vacuum treatment, continuous casting, casting blank heating, rolling, accelerated cooling, and straightening. The present invention, by means of reasonably configuring chemical components and smelting and rolling processes, as well as performing accelerated cooling of a rolled steel rail head, rail web and rail bottom at different cooling rates, achieves good matching of yield ratio of the steel rail head and impact toughness of the rail web, thereby improving the overall service performance and service life of the steel rail, and meeting the requirements of railway development; the method is simple, has strong operability, and is easy to popularize and apply.
A tempering-free wear-resistant hot rolled strip, includes components in percentage by weight: 0.08-0.22% of C, 0.1-0.55% of Si, 0.8-1.5% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, 0.01-0.055% of Als, 0.005-0.019% of Ti, and less than or equal to 0.007% of N. A method for producing the same includes: desulfurizing molten iron, smelting desulfurized molten iron, and casting into a blank; heating the casting blank; performing rough rolling; performing finish rolling; performing rapid cooling; performing coiling; and performing conventional temper rolling. According to the present disclosure, on the premise that the tensile strength of a steel plate is greater than or equal to 1100 MPa and the elongation is greater than or equal to 12%, the steel plate has a surface Brinell hardness of 330-390 and a core hardness that is 95% or above of the surface hardness.
Disclosed in the present invention are a steel rail in which abrasion and rolling contact fatigue are well coupled and a production method therefor. The chemical components of the steel rail comprise, in percentages by weight: 0.75-0.88% of C, 0.60-0.80% of Si, 0.90-1.30% of Mn, 0.08-0.15% of V, 0.15-0.30% of Cr, 0.02-0.08% of Nb, 0.004-0.008% of B, P ≤ 0.025%, S ≤ 0.025%, and the balance being Fe and inevitable impurities. According to the present invention, by carrying out staged accelerated cooling on a rail head, the cooling speed and the cooling time of each stage are reasonably distributed; and by reasonably controlling the pearlite interlamellar spacing of the rail head metallographic structure, the development of rolling contact fatigue and abrasion of a steel rail can be well coupled, thereby improving the overall use performance and service life of the steel rail. The production method is simple, has a high operability, and is easy to popularize and apply.
C22C 38/02 - Ferrous alloys, e.g. steel alloys containing silicon
C22C 38/04 - Ferrous alloys, e.g. steel alloys containing manganese
C22C 38/24 - Ferrous alloys, e.g. steel alloys containing chromium with vanadium
C22C 38/26 - Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
C22C 38/32 - Ferrous alloys, e.g. steel alloys containing chromium with boron
B21B 45/02 - Devices for surface treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
C21D 1/78 - Combined heat-treatments not provided for above
The present invention relates to the field of hot rolled pipeline steel, and discloses a continuous hot-rolled high-strength pipeline steel coil having an extremely high thickness specification, the mass percentages of chemical components thereof being: C: 0.030-0.055％, Si: 0.10-0.30％, Mn: 1.30-1.65％, P: ≤0.015％; S: ≤0.0015％, Cr: ≤0.20％, Ni≤0.10％, Mo: 0.08-0.20％, Nb: 0.04-0.07％, Ti: 0.01-0.025％, Al: 0.01-0.045％, and the remainder being Fe. Also disclosed in the present invention is a manufacturing method for continuous hot-rolled high-strength pipeline steel coil having an extremely high thickness specification. The continuous hot-rolled high-strength pipeline steel coil having an extremely high thickness specification and the manufacturing method therefor of the present invention can significantly improve the strength, toughness, and manufacturability of high-thickness pipeline steel, thereby achieving good strength and toughness matching and a low yield ratio.
5050 greater than or equal to 1.6 T; materials used are basic, the production costs are low, and the present invention can completely satisfy a requirement for steel having a yield strength of 1000 MPa or more used for a rotor magnetic yoke of a hydroelectric generator that is needed by a 100 million kilowatt capacity single unit.
C21D 8/12 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
13.
ONLINE COLOR DIFFERENCE DETECTION SYSTEM AND DETECTION METHOD
The present invention discloses an online color difference detection system and detection method, and belongs to the color difference detection field, the system including: an online non-contact colorimeter and a bracket, the online non-contact colorimeter being located on the bracket, and the online non-contact colorimeter emitting a light source directed towards a sample under detection to perform color difference detection on the sample under detection, wherein an angle between reflected light received by a reflected light meter of the online non-contact colorimeter and a vertical line of the sample under detection has an error within plus or minus 1 degree from an angle between reflected light received by a reflected light meter of an offline benchtop colorimeter and the vertical line of the sample under detection.
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/25 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
14.
CONTROLLED-ROLLED AND CONTROLLED-COOLED HIGH-STRENGTH PEARLITIC STEEL RAIL, AND PRODUCTION METHOD THEREFOR
Disclosed are a controlled-rolled and controlled-cooled high-strength pearlitic steel rail and a production method therefor. The chemical components of the steel rail comprise, in percentage by mass: 0.71-0.85% of C, 0.45-0.70% of Si, 0.35-0.70% of Mn, 0.2-1.0% of Cr, 0.05-0.1% of V, 0.005-0.08% of Nb, 0-0.025% of P, and 0-0.015% of S, with the balance being Fe and inevitable impurities; and the steel rail has a tensile strength ≥ 1360 MPa, an elongation rate ≥ 12%, a railhead tread hardness ≥ 390 HB, a hardened layer depth ≥ 30 mm, a fine lamellar pearlite structure, and a pearlite lamella spacing ≤ 90 nm at a depth of 30 mm from the surface of the steel rail. In the present invention, the steel rail maintains good toughness and plasticity, while the strength and hardness thereof are improved.
An on-line color difference measurement system and method, which belong to the field of color difference measurement. The system comprises: an on-line non-contact colorimeter (1) and a support. The on-line non-contact colorimeter (1) is located on the support, and a light source emitted by the on-line non-contact colorimeter (1) is directed to a tested sample (4), so as to perform color difference measurement on the tested sample (4), wherein the error between the angle between reflected light (10) received by a reflected light measurer (9) of the on-line non-contact colorimeter (1) and a vertical line of the tested sample (4), and the angle between reflected light received by a reflected light measurer of an off-line desktop colorimeter (7) and the vertical line of the tested sample (4) is within plus or minus 1 degrees. Adjusting a measurement value of an on-line non-contact colorimeter (1) to be consistent with a measurement value of an off-line desktop colorimeter (7) improves the accuracy of a measurement value, thereby acquiring measurement data which can be used for product testing release and can be recorded into a quality assurance certificate level.
Disclosed is an X90-grade high-strength pipeline steel plate coil having a thickness of ≥ 20 mm, comprising C, Si, Mn, P, S, Cu, Ni, Cr, Mo, Nb, V, Ti, N, Al, Ca and B, with the balance being Fe and inevitable inclusions, and with 0.163% to 0.19% of Pcm and 2.65% to 2.85% of Mn + Cr + 3Mo. Further disclosed is a method for manufacturing an X90-grade high-strength pipeline steel plate coil having a thickness of ≥ 20 mm, the process flow thereof involving: smelting, casting blank heating, controlled rolling and controlled cooling. The construction requirement of an oil and gas delivery pipeline ≥ 40 billion m3/a can be met, and -20ºCCVN ≥ 305 J, -15ºCDWTT ≥ 85%, and a uniform elongation Agt ≥ 5% are also met.
A tempering-free wear-resistant hot-rolled strip steel, comprising the following ingredients in weight percentage: C: 0.08-0.22%, Si: 0.1-0.55%, Mn: 0.8-1.5%, P≤0.012%, S≤0.005%, Als: 0.01-0.055%, Ti: 0.005-0.019%, and N≤0.007%; the production method comprises: smelting desulphurised molten iron and casting into blanks; heating the cast blanks; rough rolling; finishing rolling; fast cooling; coiling; and conventional levelling. The present invention, whilst ensuring that the tensile strength of the steel plate is ≥1100 MPa and the elongation is ≥12%, enables the Brinell hardness of the surface of the steel plate to be 330-390, and the hardness of the core to reach more than 95% of the hardness of the surface, improving the hardness uniformity of the steel plate in the direction of thickness, and increasing the service life by more than 20% compared with wear-resistant steel of the same level; the alloying elements are simple and no expensive element is added, no tempering is required, and quenching is performed only online, so that the production process is short, energy consumption can be reduced by at least 15%, and the unevenness reaches no more than 4.5 mm/m.
Disclosed is a steel rail that is resistant to chloride ion corrosion and a preparation method, which comprises the following according to weight percentage: C: 0.66％-0.76％, Si: 0.53％-0.73％, Mn: 0.9％-1.7％, P≤0.012％, S≤0.005％, Nb: 0.020％-0.030％, Als≤0.003％, Cr: 1.2％-2.2％, Cu: 2％-4％, Co: 0.40％-0.65％, H≤0.00006％, O≤0.0006％, and the remainder is Fe and impurity elements. By means of controlling the shape of inclusions and producing a dense barrier layer on the steel rail surface when rolling a steel rail track, the corrosion of the steel rail by chloride ion is prevented; when the steel rail serves in an environment in which the content of chloride ion is relatively high (2.2-3.5%), the relative corrosion resistance thereof can be improved to more than 4 times that of an U75V steel rail and an U71Mn steel rail that are used for a railroad in China.
A production method that reduces the residual stress of a heat-treated steel rail, and the resulting steel rail. The method comprises: carrying out on-line accelerated cooling treatment on a hot rolled steel rail, where the starting cooling temperature is 700-880°C, the cooling speed of a rail head is 5-8°C/s, the cooling speed of a rail bottom is 1.5-3°C/s, and cooling to reduce the temperature of the rail head to 460-550°C; carrying out slow cooling treatment at a slow cooling speed of 0.5-1°C/s, until the temperature of the rail head is reduced to 350-450°C; and keeping the cooling speed of the rail head as 0.5-1 °C/s, controlling the cooling speed of the rail bottom at 0.5-2°C/s, and when a temperature difference of the rail head and the rail bottom reaches a certain range, stopping accelerated cooling and carrying out natural cooling to room temperature. The production method may effectively reduce the residual stress of the rail bottom of the steel rail, and improve the service life of the steel rail and the travel safety.
Disclosed is a hot-rolled strip steel fully-continuous production device for ferrite rolling, the device sequentially comprising a continuous casting machine (1), a high-pressure water rotating descaling device (2), a four-stand large reduction rough rolling unit (3), a drum shear (4), four thermo detectors (5a, 5b, 5c, 5d) respectively arranged behind the four-stand large reduction rough rolling units, in front of and behind a three- or four-stand finishing rolling unit and in front of down coilers, a multi-functional cold control device (6), the three- or four-stand finishing rolling unit (7), a high-speed flying shear (8), and the down coilers (9a, 9b). The device has a short production line, and a high-pressure water descaling function and an intermediate billet cooling function are integrated into same. The rolling mill arrangement, the four thermo detectors and the short-distance down coilers of the device are used such that the intermediate billet cooling load can be reduced, and accurate temperature control over the process is achieved. Further disclosed is a hot-rolled strip steel fully-continuous production method for ferrite rolling. Based on the method, the energy consumption and the cost are low, the product quality is good, the thickness is small, and the performance requirement of replacing cold with hot can be better met.
B21B 1/46 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-sectionSequence of operations in milling trainsLayout of rolling-mill plant, e.g. grouping of standsSuccession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
B21B 45/06 - Devices for surface treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling of strip material
B21B 45/08 - Devices for surface treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling hydraulically
B21B 37/74 - Temperature control, e.g. by cooling or heating the rolls or the product
21.
STEEL RAIL INLINE HEAT TREATMENT FLATNESS CONTROL METHOD
A steel rail inline heat treatment flatness control method. The method comprises the steps of: 1) a bending treatment: when rolled, a steel rail goes through a bending machine to control that the hot steel rail has a curvature of 0.4-1.0 mm/1.5 m bending towards the bottom; 2) a heat treatment: accelerated cooling of the steel rail during the heat treatment is divided into two stages, the time for accelerated cooling in the first stage is 60-100 seconds, the ratio in terms of the flow of a cooling medium applied to the head and the bottom of the steel rail is 4-7 : 1; the time for accelerated cooling in the second stage is 25-50 seconds, and the ratio in terms of the flow of the cooling medium applied to the head and the bottom of the steel rail is 1 : 3-6; and the temperature of the head of the steel rail is 60-120 °C lower than the bottom when the heat treatment is finished. The flatness of the steel rail produced per the steel rail inline heat treatment flatness control method is 0.9-1.2 mm/1.5 m.
A press hardening steel by a thin slab casting and direct rolling has a tensile strength of 1500 MPa or more. The press hardening steel has a components by weight percent: C: 0.21-0.25%, Si: 0.26-0.30%, Mn: 1.0-1.3%, P≤0.01%, S≤0.005%, Als: 0.015-0.060%, Cr: 0.25-0.30%, Ti: 0.026-0.030% or Nb: 0.026-0.030% or V: 0.026-0.030%, or a mixture of two or more of the above in any proportion; B: 0.003-0.004%, and N≤0.005%. A method for producing the press hardening steel includes following steps: hot metal desulphurization; electric-furnace or converter smelting and refining; continuous casting; descaling, then entering a soaking furnace; heating and soaking; high-pressure water descaling, then entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.
C22C 38/18 - Ferrous alloys, e.g. steel alloys containing chromium
B21B 45/08 - Devices for surface treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling hydraulically
B21B 1/46 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-sectionSequence of operations in milling trainsLayout of rolling-mill plant, e.g. grouping of standsSuccession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
A press hardening steel by a thin slab and having a tensile strength of 1900 MPa or more includes following components by weight: C: 0.31-0.40%, Si: 0.36-0.44%, Mn: 1.6-2.0%, P≤0.006%, S≤0.004%, Als: 0.015-0.060%, Cr: 0.36-0.49%, Ti: 0.036-0.045% or Nb: 0.036-0.045% or V: 0.036-0.045% or a mixture of any two or more of the above in any proportion, B: 0.004-0.005%, Mo: 0.26-0.35%, and N≤0.005%. A method for producing the press hardening steel includes following steps: molten iron desulphurization; smelting and refining by an electric furnace or converter; continuous casting; descaling treatment before entering a soaking furnace; heating and soaking; high pressure water descaling before entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.
A press hardening steel by a medium thin slab and having a tensile strength of 1500 MPa or more, includes following components by weight percent: C: 0.21%-0.25%, Si: 0.26%-0.30%, Mn: 1.0%-1.3%, P≤0.01%, S≤0.005%, Als: 0.015%-0.060%, Cr: 0.25%-0.30%, Ti: 0.026%-0.030% or Nb: 0.026%-0.030% or V: 0.026%-0.030% or a mixture of any two or more of the above in any proportion, B: 0.003%-0.004%, Mo: 0.17-0.19% and N≤0.005%. A method for producing the press hardening steel includes following steps: molten iron desulphurization; smelting and refining by an electric furnace or converter; continuous casting; descaling treatment before entering a soaking furnace; hating and soaking; high pressure water descaling before entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.
C21D 8/02 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
C21D 9/00 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor
C21D 8/04 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
C21D 9/48 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for sheet metals deep-drawing sheets
C21D 8/00 - Modifying the physical properties by deformation combined with, or followed by, heat treatment
C22C 38/12 - Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium or niobium
Provided is a hot forming steel directly rolled through a medium and thin slab and having tensile strength larger than or equal to 1900 MPa. The steel comprises the following components by weight percent: C: 0.31~0.40%, Si: 0.36~0.44%, Mn: 1.6~2.0%, P≤0.006%, S≤0.004%, Als: 0.015~0.060%, Cr: 0.36~0.49%, Ti: 0.036~0.045% or Nb: 0.036~0.045% or V: 0.036~0.045%, or a mixture of the above two or more in any ratio, B： 0.004~0.005%, Mo: 0.26~0.35%, Ni: 0.11~0.20%, and N≤0.005%. The production steps comprise: desulphurizing molten iron; electric furnace or converter smelting and refining; continuous casting; descaling treatment before entering a soaking furnace; soaking; heating; high-pressure water descaling before entering a rolling mill; rolling; cooling; batching; austenitizing; mould punching and shaping; and quenching. The production process is short, with good product surface quality, high thickness precision, and meets the quality requirements of cold-rolled products, so that complex deformation can be completed successfully, with no rebound after deformation, and high dimensional accuracy of parts.
Thin thermoforming steel rolled directly from a thin slab and having tensile strength greater than or equal to 1900 MPa, comprising the following components by weight: C: 0.31-0.40%, Si: 0.36-0.44%, Mn: 1.6-2.0%, P≤0.006% , S≤.004%, Als: 0.015-0.060%, Cr: 0.36-0.49%, Ti: 0.036-0.045% or Nb: 0.036-0.045% or V: 0.036-0.045% or a mixture of any two or more of the above in any proportion, B: 0.004-0.005%, Mo: 0.26-0.35%, and N≤0.005%. Production steps: molten iron desulphurization; smelting and refining by an electric furnace or converter; continuous casting; descaling treatment before entering a soaking pit; soaking; heating; high pressure water descaling before entering a rolling mill; rolling; cooling; coiling; austenitizing; mold stamping forming; and quenching. The thermoforming steel is high strength, has a short manufacturing process and good product surface quality, and the accuracy of thickness may be controlled within ±0.03mm, thus greatly reducing energy consumption.
Thermoforming steel rolled directly from a medium thin slab and having tensile strength greater than or equal to 1500 MPa, comprising the following components (weight%): C: 0.21%-0.25%, Si: 0.26%-0.30%, Mn: 1.0%-1.3%, P≤0.01%, S≤0.005%, Als: 0.015%-0.060%, Cr: 0.25%-0.30%, Ti: 0.026%-0.030% or Nb: 0.026%-0.030% or V: 0.026%-0.030% or a mixture of any two or more of the above in any proportion, B: 0.003%-0.004%, Mo: 0.17-0.19% and N≤0.005%. Production steps comprise: molten iron desulphurization; smelting and refining by an electric furnace or converter; continuous casting; descaling treatment before entering a soaking pit; soaking; heating; high pressure water descaling before entering a rolling mill; rolling; cooling; coiling; austenitizing; mold stamping forming; and quenching. The production process of the present invention is short, surface quality thereof is good, and thickness precision is high; quality requirements for cold-rolled products may be met, and complex deformation may be smoothly completed; moreover, no resilience is present after deformation, and dimensional accuracy of parts is high.
Provided is a thin thermoformed steel directly rolled using thin slabs and having tensile strength of ≥1500 MPa, having a component wt% of C: 0.21-0.25%, Si: 0.26-0.30%, Mn: 1.0-1.3%, P≤0.01%, S≤0.005%, Als: 0.015-0.060%, Cr: 0.25-0.30%, Ti: 0.026-0.030% or Nb: 0.026-0.030% or V: 0.026-0.030%, or a mixture of two or more of the above in any proportion; B: 0.003-0.004%, and N≤0.005%. Production steps: hot metal desulfurisation; electric-furnace or converter smelting and refining; continuous casting; descaling, then entering a soaking pit; soaking; heating; high-pressure water descaling, then entering a rolling mill; rolling; cooling; coiling; austenitizing; die stamping; quenching. The process of the method is short, the quality of the surface of the product is good, and thickness and precision are high, thus satisfying the quality requirements of cold-rolled products; complicated deformation is successfully accomplished and there is no rebound after deformation, and the precision of sizing components is high.
patents
