3543 results about "Hot rolled" patented technology

The invention provides a thin high-strength hot-rolled steel sheet with a thickness of not more than 3.5 mm which has excellent stretch flangeability and high uniformity in both shape and mechanical properties of the steel sheet, as well as a method of producing the hot-rolled steel sheet. A slab containing C: 0.05-0.30 wt %, Si: 0.03-1.0 wt %, Mn: 1.5-3.5 wt %, P: not more than 0.02 wt %, S: not more than 0.005 wt %, Al: not more than 0.150 wt %, N: not more than 0.0200 wt %, and one or two of Nb: 0.003-0.20 wt % and Ti: 0.005-0.20 wt % is heated at a temperature of not higher than 1200° C. The slab is hot-rolled at a finish rolling end temperature of not lower than 800° C., preferably at a finish rolling start temperature of 950-1050° C. A hot-rolled sheet is started to be cooled within two seconds after the end of the rolling, and then continuously cooled down to a coiling temperature at a cooling rate of 20-150° C./sec. The hot-rolled sheet is coiled at a temperature of 300-550° C., preferably in excess of 400° C. A fine bainite structure is obtained in which the mean grain size is not greater than 3.0 mum, the aspect ratio is not more than 1.5, and preferably the maximum size of the major axis is not greater than 10 mum.

The invention provides automobile steel with low cost and high strength ductility balance and a preparation method thereof, belonging to the technical field of automobile steel. A multiphase, metastable and multiscale M<3> type organization structure is obtained based on reasonable design of chemical composition and partition of alloy elements and crucially based on the control of martensite phasetransformation, the repartition of solute such as C/Mn and the like and the austenite inverse phase transformation. The invention is characterized in that the martensite structure is obtained by using 0.02-0.50 wt%C and 3.50-9.00 wt%Mn in the cooling process of the inductrial production of steel plates and steel coils and the like; and superfine adverse transformation austenite and alpha phase substrate can be obtained through the partition of Mn and C in the heat preserving process between 100 DEG C below Acl and Acl, thus realizing the industrial production of hot rolled sheets and cold rolled sheets with high strength ductility balance used in automobiles. The invention has the advantages that the intensity is 0.7-1.3 GPa, the extension rate is 55-30% and the strength ductility balanceis 35-55 GPa%.

The invention discloses a method for controlling the planeness of cold-rolling strip steel, which comprises the following steps of: carrying out planeness feed-forward control, planeness feedback control and coordination control between both; detecting the cross-section shape and the planeness of a hot rolling incoming material, and actually-measured rolling technological parameters of each frame in real time based on a profiler configured on a No. 1 frame inlet, wherein the parameters comprise rolling force actually-measured values and plate shape adjusting mechanism actually-measured values, and carrying out the feed-forward control on the planeness of each frame outlet; and actually measuring the planeness of the cold-rolling strip steel based on a plate shape roller configured on an outlet of a cold rolling mill, and intensively carrying out the feedback control on the planeness of a final frame outlet. The method can eliminate the influences of the cross-section shape and the planeness of the hot rolling incoming material and fluctuations of the rolling technological parameters on the planeness of the final frame outlet to improve the planeness quality of the cold-rolling strip steel on the one hand, and can automatically control the planeness of each frame outlet, reduce incidence of abnormal conditions, such as fracture surfaces, deviation and the like, and improve the stability in the production process of tandem cold strip rolling on the other hand.

The invention provides a high-strength cold-rolled plate with favorable forming property and a preparation method thereof. The high-strength cold-rolled plate comprises the following chemical components: 0.05-0.6% of C, being more than or equal to 0.3% and being less than 0.8% of Si, 0.5-4.0% of Mn, being more than ore equal to 0.2% of P, being more than or equal to 0.002% of S, being more than or equal to 0.1% of Al, being more than or equal to 0.01% of N, and the balance of Fe and inevitable impurities. The preparation method comprises the following steps: smelting, continuous-casting, hot-rolling, cold-rolling and continuous-annealing, wherein annealing temperature is higher than that of Ac3, holding time is 3-30 minutes; quickly cooling to 100-600 DEG C at the rate of 30-100 DEG C/s, keeping the temperature for 3-30 minutes, and finally cooling to room temperature at the rate of 5-30 DEG C/s. The invention adopts low-silicon low-aluminum component design and heat treatment technique; the strength level of the produced bainite TRIP steel is greater than 780 MPa; and the produced bainite TRIP steel has favorable strength, plasticity, extensibility, chambering property and coating property.

A composition and method of making a high-strength low-alloy hot-rolled steel sheet, strip, or plate bearing titanium as the principal or only microalloy strengthening element. The steel is substantially ferritic and has a microstructure that is at least 20% acicular ferrite. The steel has a minimum yield strength of at least 345 MPa (50 ksi) and even over 621 MPa (90 ksi) adding titanium as the lone microalloy element for strengthening, with elongation of 15% and more. Addition of vanadium, niobium, or a combination thereof can result in yield strengths exceeding 621 MPa (90 ksi). Effective titanium content, being the content of titanium in the steel not in the form of nitrides, oxides, or sulfides, is in the range of 0.01 to 0.12% by weight. The manufacturing process includes continuously casting a thin slab and reducing the slab thickness using thermomechanical controlled processing, including dynamic recrystallization controlled rolling.

The invention provides a kind of hot-rolled double-sided enamel-used nickelclad, the chemical components of which is: C 0.02%-0.06%, Si <=0.50%, Mn 0.15%-0.40, P <=0.15%, S <=0.006%, N<=0.003%, Ti 0.08%-0.20%, Als 0.005%-0.055%, Ti/C 2.2-5,unavoidable impurities and Fe as balance. The architecture of the nickelclad is ferrite with grain diameter = 2 mum-20 mum under hot rolling conditions, and TiC particles (diameter < 20nm is uniformly distinguished in the architecture. V 0.015%-0.060% and/or Cr 0.05%-0.20% can also be added. The production method of the clad is: producing unburnt earthenware with continuous cast method, heating to 1180-1260DEG C, descaling with high-handed water, rough rolling, finish rolling for 5-7 passes at 1100-960 DEG C and finally at 920DEG C-840DEG C, continuously cooling to 450- 630DEG C at a speed of >=30DEG C/S in 0-7S, and coiling. The nickelclad has the advantages of good performance and high strength, and can meet the requirement of large scaled engineering fembers.

The invention discloses a controlling method of iron oxide sheet of rolled band steel surface of middle-thin board blank, which is characterized by the following: controlling component; proceeding heat load directly; heating to remove phosphor; rolling under high temperature; forcing to cool; controlling Si content in the steel; eliminating red ferric oxide on the surface of heat roll steel; fitting for the steel with not more than 0.18%C, not more than 0.20% Si, not more than 1.50% Mn, not more than 0.015% P, not more than 0.01% S and Nb, V and Ti.

The invention relates to high-performance marine mooring chain steel and a manufacturing method thereof. The method comprises the following steps: a. tapping compositions comprise the following by weight percentage: C: 0.16 to 0.27, Mn: 0.40 to 1.45, Si: 0.15 to 0.50, Cr: 1.25 to 2.50, Ni: larger than 0 and less than 1.20, Mo: 0.20 to 0.60, Al: 0.01 to 0.06, N: 0.004 to 0.015, S: not larger than 0.005, P: not larger than 0.015, Cu: larger than 0 and less than 0.50, and the balance of Fe; b. a steel ingot or a continuous casting billet is casted after the steps of primary smelting in an electric stove or a converter, external refining and vacuum degassing; c. the charging temperature of a heating oven is not larger than 900 DEG C, the heating rate is not larger than 150 DEG C/h; when being raised to 1100 to 1300 DEG C, the temperature is kept for more than 40 minutes, cogging bloom or rolling by a finisher is carried out, and the finishing temperature is not larger than 1050 DEG C; and d. after heated at the temperature of 1000 to 1250 DEG C, the cogged ingot is hot-rolled or forged into round steel, the finishing temperature is not larger than 1050 DEG C, and after rolling, the steel is air-cooled, slow cooled or softening heat-treated at the temperature of not less than 600 DEG C. The performance of finished products achieves or exceeds the requirement of level 4.5 and level 5 of mooring chain steel.

The invention relates to a low-alloyed and high-strength Q and amp of a C-Mn-Al system; P steel; and a manufacturing method thereof, which belong to the technical field of metal materials. The method comprises the following processing steps of: (1) smelting and cast blocking: the mass percentages of the components are as follows: 0.16 percent to 0.25 percent of C, less than or equal to 0.40 percent of Si, 1.20 percent to 1.60 percent of Mn, 1.0 percent to 1.5 percent of Al, less than or equal to 0.02 percent of P, less than or equal to 0.008 percent of S and the balance of ferrite. (2) rolling: after the multi-pass hot-rolling of rough rolling and finish rolling, wherein, the deformation of roughing pass is 10 percent to 30 percent, the total deformation of the finish rolling is more than 60 percent, a hot rolled plate is subjected to multi-pass cold rolling, the deformation is 5 percent to 50 percent, and the plate is rolled to be a thin plate with the thickness being 0.6 to 2.0mm. (3) heat treating: firstly, austenitizing of 850 to 930 DEG C is carried out in a heating furnace, temperature is kept for 100 to 200 seconds and then rapid quenching is carried out to reach 230 to 250 DEG C, the temperature is kept for 20 to 40 seconds, after that the temperature is kept in 300 to 400 DEG C for 120 to 3600 seconds, at last fast cooling is carried out to room temperature (the speed of the cooling is not less than 10 DEG C/s). The Q and amp and the P steel have economic components, good quality of the surface, high strength and good shaping resistance. The strength and ductility product can reach over 37000MPa question mark percent.

This invention relates to an oriented silicon steel and its processing method and equipment. It comprises of 0.035~0.060% of C, 2.5~3.5% of Si, 0.08~1.8% of Mn, 0.005~0.010% of S, 0.015~0.035% of Al, 0.0050~0.0090% of N, 0.01~0.15% of Sn, 0.010~0.030% of P and 0.05~0.12% of Cu, with the rest iron. The processing method includes: a) smelting; b) hot rolling. Billets are heated to 1100~1200 deg.C and rolling temperature is lower than 1200 deg.C with a finishing temperature of above 850 deg.C and a coiling temperature of below 650 deg.C; c) normalizing. Hot-rolled boards are normalizing annealed at 1050~1180 deg.C for 1~20 seconds and 850~950 deg.C for 30~200 seconds and then cooled quickly; d) cold rolling. Boards are rolled to product thickness by one-off cold rolling or repetitious cold rolling with intermediate annealing; e) nitriding, decarbonization and high-temperature and hot-leveling annealing with boards coated with high-temperature annealing isolation agents mainly made of MgO.

The invention provides 980 MPa-grade hot-rolled high-strength high-hole-expansion-ratio steel and a manufacturing method thereof. The 980 MPa-grade hot-rolled high-strength high-hole-expansion-ratio steel comprises, by weight, 0.05%-0.10% of C, 0.1%-0.8% of Si, 1.5% -2.5% of Mn, 0-0.015% of P, 0-0.005% of S, 0-0.003% of O, 0.02%-0.08% of Al, 0-0.005% of N, 0.05%-0.15% of Ti, 0.02%-0.06% of Nb, 0.1%-1.0% of Cr, 0.01%-0.10% of V, and the balance Fe and inevitable impurities, wherein the chemical components meet the relations that 0.15%<=Nb+Ti+V<=0.25%, and 0.01%<=(Ti-3.42N)/4+V/4.24<=0.06%. The microstructure of the steel is made of granular bainite and martensite; the yield strength of the steel is equal to or higher than 900 MPa, the tensile strength of the steel is equal to or higher than 980 MPa, the ductility of the steel is equal to or higher than 15%, and the hole expansion ratio of the steel is equal or higher than 50%; and the 980 MPa-grade hot-rolled high-strength high-hole-expansion-ratio steel has excellent strength, ductility and hole expansion matching and can be widely applied to thinned high-strength complexly-formed components such as an automobile chassis, a crossbeam and a wheel.

The invention provides a hot rolled steel plate with excellent low-temperature toughness for a thick submerged pipeline and a production method of the hot rolled steel plate. The hot rolled steel plate comprises the following chemical components by weight percentage: 0.02%-0.07% of C, 0.15%-0.40% of Si, 1.0%-1.70% of Mn, less than or equal to 0.020% of P, less than or equal to 0.003% of S, less than or equal to 0.06% of Nb, less than or equal to 0.025% of Ti, less than or equal to 0.06% of V, less than or equal to 0.20% of Mo, less than or equal to 0.25% of Cu, 0.10%-0.30% of Ni, less than orequal to 0.25% of Cr, less than or equal to 0.008% of N, 0.010%-0.040% of Al, more than or equal to 2 of Al/N and the rest Fe and inevitable impurities. According to the steel for the submerged pipeline with the thickness being over 28mm, disclosed by the invention, the transversal and longitudinal bending strength can reach over 480MPa or 510MPa, the transversal and longitudinal tensile strengthcan reach over 560MPa or 600 MPa, the transversal impact toughness at the temperature of 60 DEG below zero is larger than or equal to 400 J, the transversal DWTT (Drop-Weight Tear Test) shearing areaat the temperature of 25 DEG C below zero is larger than or equal to 85%, simultaneously, the corrosion resistant of the steel plate is excellent, and the result of a 96-hour HIC (Hydrogen Induced Cracking) test conforms to the requirements of the standard 0284 of the NACE (National Association of Corrosion Engineers). The hot rolled steel plate is suitable to be as a raw material for manufacturing a pipeline for submerged oil and gas transmission.

The invention provides a high strength cold-rolled plate with excellent formability, containing: no more than 0.0040% of C, 0.02-0.15% of Si, 0.20-1.00% of Mn, 0.02-0.09% of P, 0.015-0.06% Ti, 0.01-0.05% of Nb, and the rest being Fe. The production method comprises: smelting, continuous casting, hot-rolling, cold rolling and continuous annealing, wherein the heating temperature of the hot-rolled billet is 1170-1270 DEG C, the finishing temperature of hot-rolling is 850-960 DEG C, and the coiling temperature is 650-760 DEG C; the cold rolling reduction percent is 60-82%; the annealing temperature is 760-880 DEG C, the thermal insulation time is 60-210s, the slow-cooling segment temperature is 630-700 DEG C, and the fast-cooling exit temperature is 300-500 DEG C; and the levelling elongationrate is 0.5-1.0%. The high strength steel plate containing phosphorus of the invention has the features of low carbon, microalloying and purity. The steel added with a certain amount of Nb and Ti hashigher plasticity. Using relevant rolling and annealing technique, the indexes of performance of the steel achieves the demand of high strength automobile stamping parts.

The invention provides a high-strength cold rolling transformation induced plasticity steel plate and a preparation method thereof. The high-strength cold rolling transformation induced plasticity steel plate comprises the following components by weight percentage: 0.1%-0.5% of C, 0.1%-0.6% of Si, 0.5%-2.5% of Mn, 0.02%-0.12% of P, less than or equal to 0.02% of S, 0.02%-0.5% of Al, less than or equal to 0.01% of N, 0.1%-1.0% of Cu and the rest Fe. The preparation method comprises the following steps of: (a) refining molten steel meeting a component condition, and casting into a blank; (b) rolling, wherein the heating temperature is 1,100-1,250 DEG C, the heat preservation time is 1-4h, the initial rolling temperature is 1,100 DEG C, the final rolling temperature is 750-900 DEG C, the coiling temperature is less than 700 DEG C, the thickness of a hot rolled steel plate is 2-4mm, and the cold rolling accumulated pressing amount is 40-80%; and (c) continuous annealing, wherein the annealing temperature is 700-Ac3+50 DEG C, the heat preservation time is 30-360s, the cooling speed is 10-150 DEG C/s, the aging temperature is 250-600 DEG C, the aging time is 30-1,200s, and the hot roller steel plate is cooled at the speed of 5-100DEG C/s to be at the room temperature. The steel plate disclosed by the invention has the bending strength of 380-1,000 MPa, tensile strength of 680-1,280 MPa and elongation of 15-30%.

The invention discloses a production method of low-silicon and low-carbon deep punching/drawing steel, bottom-blowing argon is performed in the whole process of converter smelting, and a single slag/double slag technique is adopted to pour out the dephosphorized slag, high-basicity slag is produced in later period, the dualistic basicity of final slag R is more than 3.5, the terminal temperature of molten steel is 1620 DEG C to 1650 DEG C, and tapping ( P ) is less than 0.012 percent. The molten steel is refined by adopting low-silicon and low-carbon high-basicity reductive slag in a LF furnace refining station, thus to manufacture reductive slag for desulphurisation, and the ( Al ) in the molten steel is less than 0.005 percent. The molten steel refined by the LF furnace is vacuum-treated by a RH vacuum furnace, the carbon and the silicon in the molten steel is circularly removed, the molten steel is continuously casted into a casting blank through a CSP sheet bar conticaster, the casting blank is sent into CSP sheet bar heat continuous rolling mill and rolled into a coiled sheet after being heated in a roller hearth soaking furnace, a hot rolled coiled sheet is coldrolled into cold rolled coiled sheet through a cold tandem mill or a single mill after being acidwashed, and leveled through a leveling machine after being annealed by a cover furnace, and a leveling divided coil is stretched and divided. The production method has the advantages that the production cost of the working procedure is saved, the consumption of the refractory consumption of the converter is reduced, the equipment investment is saved, the process of the production technique is steady and smooth, the n value of the cold rolled plate is bigger than 0.23, the r value thereof is bigger than 2.1, and the deep punching performance and the extensibility are good.

The invention discloses high-strength, high-toughness and high-plasticity martensitic stainless steel, and belongs to the technical field of metallurgy. The martensitic stainless steel comprises the following components in percentage by weight: 0.15 to 0.4 percent of C, 0 to 0.12 percent of N, 0.2 to 2.5 percent of Si, 0.4 to 3.0 percent of Mn, less than or equal to 0.02 percent of S, less than or equal to 0.02 percent of P, 13.0 to 17.0 percent of Cr, 0 to 5.0 percent of Ni, 0 to 2.0 percent of Mo, 0 to 0.3 percent of V, 0 to 0.2 percent of Nb, 0 to 0.05 percent of Ti, 0 to 0.8 percent of Al and the balance of Fe and inevitable impurities. A preparation method comprises the following steps of (1) smelting molten steel according to the set components, and solidifying the molten steel to form an ingot blank by using a continuous casting machine or a casting mold; (2) hot-rolling the ingot blank to form a hot-rolled plate blank; (3) heating the hot-rolled plate blank to 950 to 1100 DEG C, preserving heat for 0.5 to 2 hours, cooling the plate blank to 25 to 200 DEG C, heating the plate blank to 350 to 500 DEG C, preserving heat for 10 to 60 minutes, and air-cooling the plate blank to room temperature. According to the martensitic stainless steel prepared by the method, dispersed remaining martensite is introduced into a microscopic structure, so that the strength, toughness and plasticity of the martensitic stainless steel are greatly improved.

The first Al-based target material for sputtering contains 0.01-10 atomic % of at least one intermetallic compound-forming element, and an intermetallic compound having a maximum diameter of substantially 50 mum or less. The second Al-based target material for sputtering has a microstructure comprising an alloy phase containing 20 atomic % or less of the intermetallic compound-forming element and Al and an Al matrix phase comprising substantially pure Al, the maximum diameter of the intermetallic compound in the alloy phase being substantially 50 mum or less. The content of the intermetallic compound forming element based on the whole structure is 0.01-10 atomic %. These target materials are produced by pressure-sintering a rapid solidification powder at 400-600° C. After the pressure sintering, the target material is preferably hot-rolled at 400-600° C.

A high strength Al-Mg alloy in plate or extrusion form having significantly improved strength in both soft and work-hardened tempers as compared with AA5083 is provided. The materials have ductility, pitting, stress and exfoliation corrosion resistances equivalent to those of the AA5083. The materials have improved long term stress and exfoliation corrosion resistances at temperatures above 80° C. The composition is 5-6% Mg, >0.6-1.2% Mn, 0.4-1.5% Zn, 0.05-0.25% Zr, up to 0.3% Cr, up to 0.2% Ti, up to 0.5% each Fe and Si, up to 0.4% each Cu and Ag, remainder Al and inevitable impurities. Manufacture of plate of this alloy is by homogenizing an ingot, hot rolling the ingot into plate in the range 400-530° C., cold rolling the plate with or without inter-annealing, final and optionally inter-annealing of the cold rolled material at temperatures in the range 200-550° C.

The invention relates to a production process for hot-rolling medium plate by adopting aluminum alloy. The aluminum alloy materials are as follows according to the weight percentage: Fe is less than or equal to 0.35, Si is less than or equal to 0.25, Cu is less than or equal to 0.10, Mn is 0.70-0.90, Mg is 4.50-4.80, Cr is 0.10-0.20, Zn is less than or equal to 0.20, Ti is less than or equal to 0.10, other impurities are less than or equal to 0.15 in total, Na is less than or equal to 5pp,, Ca is less than or equal to 5ppm, and Al is the balance; and the sum of all components is 100. The main process comprises the following steps of melting, milling, heating, hot rough rolling or fine rolling. The invention adopts a soaking process during the processing of the aluminum alloy, mainly adopts two measures of milling sides and rolling the sides to solve the edge crack problem, controls the thickness difference and the plate form as well as oil spot and scuffing, and develops the production process for hot-rolling the medium plate by adopting the 5083 aluminum alloy.

A cold rolling method for preparing high-Si steel sheet containing Fe (85-96 Wt%) and Si (4-15) includes such steps as providing raw material containing Si, B and Fe, smelting, casting, forging, hot rolling, warm rolling, heat treating and cold rolling.

The present invention is high magnetic induction and high grade non-orientation electrical steel and its making process. The high magnetic induction and high grade non-orientation electrical steel consists of C not more than 0.0050 wt%, N not more than 0.0030 wt%, Si 1.50-2.50 wt%, Al 0.80-1.30 wt%, Mn 0.20-0.50 wt%, P not more than 0.030 wt%, S not more than 0.005 wt%, Sb 0.03-0.10 wt% or Sn 0.05- 0.12 wt%, and B 0.0005-0.0040 wt%, except Fe and inevitable impurities. Its making process includes initial rolling and high temperature winding to obtain ideal hot rolled steel belt structure; cold rolling to provide the energy for crystal grain growth in re-crystallizing annealing, and re-crystallizing annealing in controlled temperature to obtain ideal crystal grain structure. It has excellent surface quality, high magnetic induction and low iron loss, and is suitable for use in high efficiency motor iron core.

A steel sheet excellent in mechanical strength, workability and thermal stability and suited for use as a raw material in such fields of manufacturing automobiles, household electric appliances and machine structures and of constructing buildings, and a manufacturing method thereof. are provided.

The steel sheet is a hot-rolled steel sheet of carbon steel or low-alloy steel, the main phase of which is ferrite, and is characterized in that the average ferrite crystal grain diameter D (μm) at the depth of ¼ of the sheet thickness from the steel sheet surface satisfies the relations respectively defined by the formulas (1) and (2) given below and the increase rate X (μm/min) in average ferrite crystal grain diameter at 700° C. at the depth of ¼ of the sheet thickness from the steel sheet surface and said average crystal grain diameter D (μm) satisfy the relation defined by the formula (3) given below:

1.2≦D≦7   formula (1)

D≦2.7+5000/(5+350·C+40·Mn)²  formula (2)

D·X≦0.1   formula (3)

wherein C and Mn represent the contents (in % by mass) of the respective elements in the steel.

The invention is the improvement on a longitudinal drainage plate for silt consolidation, filter cloth and a drainage plate core, which is characterized in that fibrous hot-pressed microporous filter cloth is planar filter cloth hot-rolled by a flat roller, the filter cloth is adhered to the surfaces of convex ribs of the drainage plate core through thermal thawing or a chemical way, the filter cloth adopts silk reeling and hot-press forming separation technology, and the drainage plate core is made of co-polypropylene, thereby overcoming the disadvantages of the prior art; and the aperture of the filter cloth can be adjusted according to treated silt, the drainage plate is difficult to block, the engineering on a soft foundation after the treatment cannot have the settlement after the construction and has smooth drainage and high drainage efficiency, and the plate core has long effective service life.

An austenitic stainless steel hot-rolled steel material can be provided which has sea-water resistance and strength superior to conventional steel. Low-temperature toughness can be maintained, which is preferable in a structural member of speedy craft. The steel material can include an austenitic stainless steel hot-rolled steel material which excels in the properties of corrosion resistance, proof stress, and low-temperature toughness. In such austenitic stainless steel hot-rolling steel material, e.g., PI[=Cr+3.3(Mo+0.5W)+16N] ranges from 35 to 40, δ cal [=2.9 (Cr+0.3Si+Mo+0.5W)−2.6 (Ni+0.3Mn+0.25Cu+35C+20N)−18] ranges from −6 to +2, and a 0.2% proof stress at room temperature is not less than 550 MPa, Charpy impact value measured using a V-notch test piece at −40° C. is not less than 100 J/cm2, and the pitting potential measured in a deaerated aqueous solution of 10% NaCl at 50° C. (Vc′100) is not less than 500 mV (as it relates to saturated Ag/AgCl).

The invention provides a high strength bainitic steel rail and a heat treatment process thereof. The steel rail comprises the following chemical compositions by weight percentage: 0.10%-0.32% of C, 0.80%-2.00% of Si, 0.80%-2.80% of Mn, Cr less than 1.50%, 0.10%-0.40% of Mo, 0-0.5% of Ni, wherein Mn, Cr and Ni satisfy the relation of: Mn+Cr+0.5Ni<=2.8%, and the balance of Fe and unavoidable impurities. The process is as below: conducting hot rolling on the steel rail or air cooling on the steel rail to room temperature, then reheating to 850-1000 DEG C for austenization; cooling the steel rail head to 620-570 DEG C with a cooling rate of 0.3-15 DEG C / s; when the temperature is lower than 620-570 DEG C, cooling to 350-200 DEG C with a cooling rate of 0.5-5 DEG C / s; and then conducting air cooling to room temperature. The invention avoids generation of excessive unstable thick M-A islands in granular bainite during air cooling to room temperature in hot rolling, reduces the risk of straightening fracture (or delayed fracture)of hot-rolled steel rail, and improves the adaptability of steel production process. The steel rail has tensile strength higher than 1400MPa, and realizes optimum matching of strength, toughness and ductility, and excellent rolling contact fatigue resistance and wear resistance.

The invention discloses a steel plate for stamping and quenching and a manufacturing method thereof. The steel plate comprises the following chemical components in percentage by mass: 0.14 to 0.28 percent of C, less than 0.40 percent of Si, 0.4 to 2.0 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.004 percent of S, 0.016 to 0.040 percent of Al, 0.15 to 0.8 percent of Cr, 0.015 to 0.12 percent of Ti, 0.001 to 0.005 percent of B, less than or equal to 0.005 percent of N, and the balance of Fe and unavoidable impurities. The manufacturing method comprises the following steps of: heating a blank to 1,150 to 1,250 DEG C, preserving heat for 2.5 to 4 hours and performing rough rolling, and then performing finish rolling under multichannel pressure and at the final rolling temperature of between 830 and 950 DEG C, performing laminar cooling, and cooling to the rolling temperature at the cooling speed of more than 10 DEG C/s and the rolling temperature of between 600 and 680 DEG C. The cold-rolled steel plate is obtained by the following steps of: performing cold rolling on a hot rolled steel strip, annealing through a pure hydrogen gas cover furnace, and oiling and packaging. The annealing temperature is 550 to 650 DEG C and the heat preserving time is 3 to 5 hours. The steel has a simple component design and high hardenability. The depth of a hardening layer of more than HRC45 is 10 to 16mm. The steel plate consists of ferrite and pearlite. After thermal stamping and quenching, an all-martensite structure can be obtained. The tensile strength is above 1,300N/mm<2>.

The invention discloses a high strength and high toughness hot-rolled steel plate, the chemical components thereof and the weight percentages of the component are: 0.03 to 0.09 percent of C, 0.15 to 0.35 percent of Si, 1.40 to 2.0 percent of Mn, 0.02 to 0.05 percent of Al, 0.05 to 0.13 percent of Nb, 0.010 to 0.025 percent of Ti, being equal to or less than 0.30 percent of Cu, being equal to or less than 0.30 percent of Cr, being equal to or less than 0.012 percent of P, being equal to or less than 0.004 percent of S, being equal to or less than 0.004 percent of N and the rest are Fe; and Ceq can not be more than 0.44, crack sensitive index Pcm can not be more than 0.23, the production steps thereof are: liquid iron pre-desulphurization, bessemerizing, LF refining, RH(VD) processing, slab blank continuous casting, slab blank reheating, temperature controlling rolling, controlled cooling, hot straightening, cold bed cooling and cooling in heap; the advantages thereof are as follows: molybdenum can be omitted and nickel can be saved, thus reducing the cost; the steel plate has good weldability, high rolling efficiency and precise production control.

The invention discloses a high-elongation cold-rolled TRIP (Transformation-Induced Plasticity) steel plate, comprising 0.15-0.25% of C, 0.4-1.5% of Si, 0.5-2.5% of Mn, 0.04-0.10% of P, less than or equal to 0.02% of S, 0.02-0.5% of Al, less than or equal to 0.01% of N, 0-0.5% of Nb, 0-0.5% of V, 0-0.5% of Ti, 0-2% of Cr, 0-1% of Mo, and the balance of Fe and inevitable impurities, wherein in the microscopic structure, the area ratio of ferrite is 10-80%, while the area ratio of residual austenite is 3-20% and the area ratio of martensite is 0-20%, and the rest part is bainite; the hot rolling heating temperature is 1100-1250 DEG C, the heat preservation time is greater than or equal to 2 h, the rolling starting temperature is equal to or higher than 1100 DEG C, the final rolling temperature ranges from 850 to 950 DEG C, and the coiling temperature is lower than 720 DEG C; the hot-rolled plate is 2-4 mm thick; accumulated compression quantity of cold rolling is 40-80%; the annealing temperature is 700-(Ac3+50) DEG C, the heat preservation time is 30-360 s, the cooling rate is 10-150 DEG C/s, the aging temperature is 300-600 DEG C, the aging time is 30-1200 s and the cooling rate is 5-100 DEG C/s; and finally, cooling is performed until the temperature reaches the room temperature.

The invention discloses a polyester FDY oil agent and a preparation method thereof. The heat resistance of the existing oil agent is poor with serious volatilization, which results in heavy smog in the workshop and seriously affects the working environment and the body health of the workers; also the oil agent has serious coking phenomena and causes yarn waste and broken ends. The ingredients of the invention and the weight percentages are as follows: 55-65% of high-temperature smoothing agent, 15-25% environment-friendly emulsifying agent, 3-10% binder, 5-8% compound anti-static agent and the rest is additive; and the high-temperature smoothing agent contains special polyether. The invention has good heat resistance and is suitable for the high-speed spinning technique of various polyester fibers (including the high denier); and the oil agent provided by the invention does not generate smoke and does not coke on the hot roll.

The present invention is related to a steel composition, a process for producing a steel product having said composition, and said steel product itself. According to the invention, a cold-rolled, possibly hot dip galvanized steel sheet is produced with thicknesses lower than 1 mm, and tensile strengths between 800 MPa and 1600 MPa, while the A80 elongation is between 5 and 17%, depending on the process parameters. The composition is such that these high strength levels may be obtained, while maintaining good formability and optimal coating quality after galvanising. The invention is equally related to a hot rolled product of the same composition, with higher thickness (typically about 2 mm) and excellent coating quality after galvanising.