43results about How to "Lower yield strength" patented technology

The invention relates to the field of matt films, in particular to a scratch-resistant BOPP (biaxially-oriented polypropylene) matt film and a preparation method thereof. The scratch-resistant BOPP matt film comprises an upper surface matt layer, a middle core layer and a lower surface layer which are sequentially arranged, the upper surface matting layer comprises a matting master batch; the matting master batch comprises 28 to 50 weight percent of co-polypropylene, 8 to 14 weight percent of ethylene-octylene block copolymer, 6 to 10 weight percent of micro-crosslinked polypropylene and 30 to 50 weight percent of high-density polyethylene; the ethylene-octylene segmented copolymer comprises a hard segment with low octylene content and high crystallinity, and an amorphous soft segment with high octylene content; the middle core layer comprises homo-polypropylene; the lower surface layer comprises a smooth surface layer or an extinction layer. By utilizing the synergistic effect of the ethylene-octylene block copolymer and the micro-crosslinked polypropylene, the compressive deformation performance, the impact strength, the tensile strength and the yield strength of the co-polypropylene are improved, the indentation of a film surface in a scraping pressure applying stage and the scratches and damages generated in a sliding stage are reduced, the scratch resistance of the upper surface matting layer is improved, and the matting effect is ensured.

The invention provides 1900MPa-grade cold-rolled medium manganese steel and a preparation method thereof, and relates to the technical field of high-strength and high-toughness automobile steel. The thickness of the 1900 MPa-grade cold-rolled medium manganese steel ranges from 1.3 mm to 1.5 mm, and the 1900 MPa-grade cold-rolled medium manganese steel is prepared from, by mass, 0.22%-0.25% of C, 6.5%-7.5% of Mn, 1.2%-1.7% of Al, 0.7%-0.9% of Si and Plt. 0.005%, Slt; 0.02% of the total weight; and the balance of Fe and inevitable impurities. The preparation method comprises the steps of raw material preparation, smelting, casting, forging, hot rolling, two-phase region annealing, tempering, cold rolling, quenching and baking treatment. According to the invention, by optimizing the two-phase region annealing process and the quenching temperature, ultrafine-grained ferrite, austenite and martensite microstructures are formed, the strength of the medium manganese steel is greatly improved, the enough percentage elongation after fracture is ensured, and the performance requirements of automobile anti-collision structural components are met.

The invention discloses steel for a bearing outer ring of a super-power wind generating set and a manufacturing process of the steel, and belongs to the technical field of wind power equipment manufacturing. The invention discloses steel for a bearing outer ring of a super-power wind generating set. The steel comprises the following components in percentage by mass: 0.48%-0.52% of C, 0.28%-0.33% of Si, 0.62%-0.66% of Mn, 0.97%-1.04% of Cr, 0.16%-0.21% of Mo, 0.005%-0.01% of Ti, 0.003%-0.008% of Zr, 0.0007%-0.001% of Ba and the balance of Fe. According to the method, alloy elements such as Ti, Zr and Ba are used for refining the sizes of grains and inclusions, meanwhile, the crushing degree and uniform distribution of the blank tissue and the inclusions are enhanced through extrusion and torsion, a fine and uniform metal flow line can be obtained after ring rolling, and the mechanical property of a forged piece is improved.

The invention discloses an arc fuse additive manufacturing bainite steel strengthening process method which comprises the steps that S1, additive manufacturing materials including a heat source, a welding wire and shielding gas are prepared; s2, various parameters in the additive manufacturing process are preset, wherein the parameters comprise dry elongation, air flow, advancing speed and wire feeding speed; s3, an additive manufacturing deposition strategy is adopted in the additive manufacturing process, additive printing is carried out according to a preset printing path, an infrared thermal imager is used for temperature detection, and when the material is cooled to 100 DEG C or 300 DEG C, next printing is carried out; and S4, 50 layers are deposited, the interlayer retention temperature of each layer is controlled to be reduced to a set value, and the material increasing sample is completed. According to the method, the workpiece can be baked in the manufacturing process, another step of treatment is not needed, and bainite steel strengthening can be completed in the additive manufacturing process.

The invention provides a correction jig, a correction method, a rotating shaft cover plate and foldable electronic equipment. The correction jig is used for correcting the straightness of a long-strip-shaped part and is provided with a first groove, and the first groove extends in the first direction; in the second direction, the range of the difference value w1-w1'between the width w1 of the first groove and the width w1 'of the long-strip-shaped part is larger than or equal to 0.05 mm and smaller than or equal to 0.1 mm, and the first direction intersects with the second direction. The correction jig is simple in structure.

The application discloses an electromagnetic riveting device based on a rotating motor and a ball screw technology and belongs to the riveting technical field. The application solves the problems of difficult joint forming and low joint strength after forming when the existing electromagnetic stamping rivetless connection device is used to perform rivetless riveting on a poor plastic connecting plate material. The application comprises a coil assembly and an electromagnetic riveting gun. The coil assembly performs softening treatment on a to-be-connected position. The electromagnetic riveting gun completes stamping rivetless connection on the softening-treated to-be-connected position. The application reduces the yield strength of the joint area of the connecting plate material only under the premise of not reducing the overall strength of the plate material, facilitates the forming of the electromagnetic stamping rivetless joint, and improves the strength of the joint.

The invention discloses beryllium brass which comprises the following components in percentage by mass: 1.9 to 2.0 percent of Be, 0.2 to 0.5 percent of Ni, 0.1 to 0.13 percent of Fe, 0.03 to 0.08 percent of Al, 0.01 to 0.03 percent of Si, 0.02 to 0.05 percent of Mg and the balance of Cu. According to the component ratio, ingot casting is conducted, the formed ingot casting is subjected to solution treatment and aging treatment, and the secondary aging temperature in the aging treatment procedure is lower than 280 DEG C. According to the scheme, the component ratio of beryllium brass and corresponding treatment process parameters are designed, and the tensile strength, yield strength and other aspects of the formed copper alloy are further improved.

The invention provides 450MPa-grade hot-dip galvanized low-density steel with low yield ratio and high corrosion resistance and a manufacturing method thereof. A steel plate comprises the following components in percentage by weight: 0.04%-0.06% of C, 0.25%-0.4% of Si, 1.4%-1.5% of Mn, 3.3%-6.5% of Al, less than or equal to 0.010% of P, 0.01%-0.03% of S, 0.01%-0.015% of RE and the balance of Fe and inevitable impurities. The manufacturing method of the steel comprises the steps of blast furnace molten iron pretreatment, converter steelmaking, continuous casting, hot continuous rolling, acid pickling, cold rolling and hot galvanizing. The steel structure is delta-ferrite, alpha-ferrite, martensite, retained austenite and sulfide, the content of the martensite is 3.5-5%, the sulfide is composed of a small amount of MnS and RE-S-O which are distributed in a dispersed mode, the small amount of MnS is separated out in the ferrite and the martensite in a dispersed mode, and the RE-S-O is distributed along the ferrite grain boundary.

The invention discloses a short-process preparation method of a low-yield-ratio double-phase high-entropy alloy, which comprises the following steps: smelting prepared alloy elements to obtain a double-phase high-entropy alloy cast ingot, heating and insulating the double-phase high-entropy alloy cast ingot, and then quenching to obtain the low-yield-ratio double-phase high-entropy alloy. One-step heat treatment is adopted, the tensile strength of the biphase high-entropy alloy cast ingot is further improved, meanwhile, the yield strength of the biphase high-entropy alloy cast ingot is reduced, the yield ratio of the biphase high-entropy alloy is effectively reduced, and compared with a rolling annealing treatment or multi-stage heat treatment process, the method has the advantages of being short in process, high in efficiency and low in cost and is suitable for industrial application and popularization.

A hot-rolled high-strength high-plasticity steel and a manufacturing method thereof, using a relatively high carbon content and silicon content, and controlling the contents of C, Mn, Si, and Al, while meeting the following requirements: 1.0≤C+Mn≤3.0, 0.8≤Si+Al≤3.0, to obtain a steel plate with a good match of high tensile strength and ultra-high plasticity; and using relatively cheap elements such as C, Si, Mn, Al, and not containing precious metal elements, greatly reducing the alloy cost. On the basis of the above-mentioned component design, the present invention adopts a hot rolling process for the first time, that is, a brand-new preparation process of hot rolling + medium-temperature coiling + annealing or tempering, to achieve a good match of high tensile strength and ultra-high plasticity of the steel plate, and also has a lower yield strength, which can avoid cracking during the stamping process of parts and improve the forming performance of steel. It is particularly suitable for the manufacture of various complex parts of passenger cars or commercial vehicles, and has good application prospects.

The application belongs to the technical field of advanced manufacturing and mine machinery equipment, and discloses a preparation method of a full-negative Poisson ratio energy-absorbing component, which solves the problem that the existing energy-absorbing component design cannot meet the high energy-absorbing demand under extreme impact working conditions. The method comprises the following steps: (1) full-parameterization design of a macro-negative Poisson ratio structure based on multi-target Bayesian optimization; (2) preparation and process parameter simulation optimization of a micro-negative Poisson ratio steel forming powder; (3) laser additive-warm subtractive composite preparation of a full-negative Poisson ratio porous structure component; and (4) post-heat treatment of the full-negative Poisson ratio porous structure component and macroscopic and microscopic toughening regulation. The application greatly improves the energy-absorbing efficiency, breaks through the bottleneck of high-precision preparation of a complex interconnected porous structure, and realizes the optimal balance of full-parameterization design and multi-target performance.

The invention discloses a multi-module combined plate-type cross wedge rolling die, relates to the technical field of cross wedge rolling, overcomes the defects that in the prior art, the inside and the outside of a machined corrugated shaft are stripped, and a roller type rolling machine is too large in size, and mainly adopts the technical scheme that the multi-module combined plate-type cross wedge rolling die is used for solving the problems. A forming space used for forming a corrugated shaft is formed between the two forming supporting assemblies. At least one of the two forming supporting assemblies is a first track assembly, a plurality of adjacent transverse rolling modules form a forming wedge, pre-extrusion stripes are further arranged on a plurality of track plates in front of the forming wedge, or the two forming supporting assemblies are a second track assembly and a third track assembly, the second track assembly is provided with pre-extrusion stripes, and the third track assembly is provided with pre-extrusion stripes. And the third track assembly is provided with a forming wedge consisting of a plurality of same adjacent transverse rolling modules, so that the corrugated shaft sequentially passes through the pre-extrusion stripes and the forming wedge during forming. The invention further discloses a rolling method for machining the corrugated shaft through the die.

A power semiconductor module (1) comprises a circuit substrate (10), a power semiconductor element (19) including a semiconductor substrate (20), and at least one joint (5). The at least one joint (5) comprises a first metal component (12) away from the semiconductor substrate (20), a second metal component (23) close to the semiconductor substrate (20), and a joint layer (15) for joining the first metal component (12) and the second metal component (23) to each other. At the same temperature, the 0.2% yield strength of the first metal component (12) is smaller than the 0.2% yield strength of the second metal component (23), and is smaller than the shear strength of the joint layer (15).

The invention belongs to the technical field of rolling, and relates to a rolling process for preparing ER50-6E welding wire steel with the tensile strength not larger than 1360 MPa and application of the ER50-6E welding wire steel. Billet steel is continuously fed, the in-furnace time is controlled to be not shorter than 110 minutes, the heating temperature is 1100-1150 DEG C, and the soaking temperature is 1170-1220 DEG C; the initial rolling temperature is 1070 DEG C to 1120 DEG C; the finish rolling temperature is not lower than 960 DEG C; and the water amount of finish rolling cooling water is reduced so that the finish rolling outlet temperature can be increased to be not lower than 1050 DEG C, the spinning temperature can be 920-950 DEG C, a heat preservation cover is completely closed, the roller way speed is low, and the cover outlet temperature is controlled to be 650 DEG C or below. The tensile strength of a hot-rolled wire rod does not exceed 500 MPa, the yield strength does not exceed 310 MPa, the yield ratio does not exceed 0.63, the hot-rolled wire rod is suitable for drawing a 0.8 mm welding wire from a phi 6.5 mm wire rod, the tensile strength of the welding wire is not larger than 1360 MPa, and the hot-rolled wire rod has good wire feeding performance.

The present application relates to a kind of aluminum alloy and its preparation method and purposes of improving pedestrian protection performance, the aluminum alloy of improving pedestrian protection performance includes by mass percentage:Si 0.45-0.7%, Mn 0.05-0.15%, Mg 0.45-0.65%, Fe≤0.1%, Cu≤0.1%, Cr≤0.04%, Zn≤0.1%, Ti≤0.1%, impurity element≤0.15%, the balance is Al;The temperature and time of preparation in solid solution treatment satisfy: t (min) =0.0013×Tc 2 -1.4305×Tc+400.29.The aluminum alloy provided by the present application, by adjusting the formula of aluminum alloy, by adopting specific solid solution treatment system, in the case of reducing the yield strength of the obtained aluminum alloy, the elongation of the aluminum alloy is ensured, to ensure that the aluminum alloy meets the requirements when used as automobile sheet.

The utility model discloses a die for manufacturing a cutting tool. The die comprises a supporting structure and a cutting structure, the outer wall of the mold device is fixedly connected with the outer wall of the supporting structure; the utility model relates to the technical field of cutter manufacturing, the device adjusts the position of a module on a heat conducting plate through a supporting structure, a die device, a threaded rod in threaded connection with a die plate in a matched mode and the module in rotary connection, and the device can adapt to manufacturing of cutting tools of different sizes. The push handle is pushed to drive the sliding block to slide in the sliding groove to interact with the slope block, the supporting plate drives the demolding plate to ascend to demold the cutter in the heat conduction plate, operation is convenient and fast, the push handle is loosened after the cutter is taken out, elastic force is automatically released to reset the demolding plate and the sliding block, preparation is made for next punching work, and time and labor cost are saved.

The present invention discloses a method for improving the room temperature mechanical properties of molybdenum-niobium single crystals, comprising the following steps: step 1, mixing a molybdenum raw material and a niobium raw material, and then performing electron beam suspension zone melting to obtain a single crystal molybdenum-niobium alloy before annealing; step 2, vacuum annealing the single crystal molybdenum-niobium alloy before annealing obtained in step 1 to obtain a single crystal molybdenum-niobium alloy with improved mechanical properties. The present invention effectively improves the strength and high temperature stability of pure molybdenum single crystals by adding the alloying element niobium to molybdenum single crystals, and vacuum anneals the molybdenum-niobium single crystals prepared by electron beam suspension zone melting, effectively reducing the internal stress of the molybdenum-niobium single crystal system, improving the microscopic defects inside the molybdenum-niobium alloy single crystal, thereby promoting dislocation slip, thereby improving the mechanical properties of the molybdenum-niobium single crystal, especially the plastic deformation ability.

The present invention relates to an energy-absorbing type connecting beam, comprising a yielding energy-absorbing component and an eddy current damping energy-absorbing component connected to the connecting beam end plate, wherein the yielding energy-absorbing component comprises a first yielding part and a second yielding part, wherein the eddy current damping energy-absorbing component is located between the first yielding part and the second yielding part, wherein the eddy current damping energy-absorbing component comprises a gear, a meshing part meshing with the gear, a cutting plate and a magnetic pole body, wherein the gear, the cutting plate and the magnetic pole body are coaxially arranged, the magnetic pole body is connected to one connecting beam end plate, the meshing part is connected to another connecting beam end plate, when the two connecting beam end plates are displaced, the yielding energy-absorbing component consumes energy, the meshing part drives the gear to rotate, and the gear drives the cutting plate to cut the magnetic flux lines, thereby realizing the energy consumption of the eddy current damping energy-absorbing component. Compared with the prior art, the eddy current damping effect is significant, and full-stage energy consumption can be realized, and it is easy to quickly replace after an earthquake, and it is easy to change the energy consumption effect.

The utility model discloses a kind of shell thermal shaping frock, including shaping module, its working surface is matched with product appearance;Heat conduction module, it is attached to the non-working surface of the shaping module;And heating and fixed module, it is arranged on the heat conduction module, for providing heat source and conducting heat to the heat conduction module.The utility model increases the plasticity of the shaping workpiece material to be waited for under high temperature, fluidity becomes good, yield strength reduces by the mode of initiative heating, this makes shaping operation become more labor-saving, deformation more uniform, can significantly reduce residual stress and springback from root, to obtain higher and more stable shaping precision (such as reach 0.05mm flatness), and there is possibility to save expensive intermediate annealing process, improve efficiency, reduce cost.

The invention provides 980MPa-grade hot-dip galvanized low-density steel with low yield ratio and high corrosion resistance and a manufacturing method thereof. A steel plate comprises the following components in percentage by weight: 0.28%-0.32% of C, 0.74%-0.82% of Si, 2.1%-2.32% of Mn, 4.3%-6.5% of Al, less than or equal to 0.010% of P, 0.01%-0.023% of S, 0.01%-0.012% of RE and the balance of Fe and inevitable impurities. The manufacturing method of the steel comprises the steps of blast furnace molten iron pretreatment, converter steelmaking, continuous casting, hot continuous rolling, acid pickling, cold rolling and hot galvanizing.

This invention discloses a briquetting device for recycling non-ferrous scrap metal, relating to the field of metal resource recycling technology. It includes a forming box, a feeding mechanism, a briquetting mechanism, and an atmosphere protection mechanism. A controller is fixedly installed on one outer wall of the forming box, and a weighing plate with a built-in weight sensor is fixedly installed on the bottom inner wall of the forming box. This invention uses a rodless cylinder-driven reciprocating feeding cylinder, combined with a screw feeder and a laser ranging probe, to achieve multi-layer, multi-point uniform distribution of material within the forming box. This effectively avoids the problem of uneven briquetting density distribution caused by material accumulation on one side in traditional devices, improving the overall density consistency of the briquetting. The weighing plate with the built-in weight sensor accurately measures the weight of the material for each briquetting operation, and combined with an ultrasonic thickness sensor to detect the thickness of the briquetting blocks after forming, this invention ensures that the weight and thickness of each briquetting block are within the set range, meeting standardized production requirements.

The invention discloses a rigid wheel and a machining method thereof and a harmonic speed reducer, and relates to the technical field of harmonic speed reducers, the rigid wheel comprises a body and a nitriding layer, the nitriding layer is formed on the surface of the body, the body of the rigid wheel is made of a nodular cast iron material with the tensile strength smaller than or equal to 700 MPa, the cutting performance of the nodular cast iron with the tensile strength is better, and the cutting performance is better. Machining is convenient, tool abrasion can be reduced, the machining efficiency is improved, and the production cost is reduced. The nodular cast iron has smaller specific gravity than quenched and tempered steel, so that the weight of the rigid wheel can be reduced; the nodular cast iron has a self-lubricating function, friction force can be reduced, and the service life of the rigid wheel is prolonged. In order to guarantee that the rigid wheel has certain strength and meets corresponding use requirements, the nitriding layer is formed on the surface of the body through nitriding treatment, the surface hardness of the nitriding layer ranges from 250 HV to 450 HV, the hardness and abrasion resistance of the rigid wheel can be improved, and then the service life of the rigid wheel is prolonged.

The utility model provides a lower limb circumference measuring device convenient to use, which relates to the technical field of medical equipment.The lower limb circumference measuring device comprises a mounting shell, first sliding grooves are formed in the outer surfaces of the two sides of the mounting shell, a second sliding groove is formed in the front surface of the mounting shell, and an adjusting mechanism is arranged in the mounting shell; measuring mechanisms are symmetrically arranged on the two sides of the adjusting mechanism, the adjusting mechanism comprises a sliding block, a connecting column is fixedly connected to the front surface of the sliding block, and a limiting disc is fixedly connected to the front end of the connecting column. According to the lower limb circumference measuring device, the bandage, the hook-and-loop fastener hook face and the hook-and-loop fastener loop face are matched to fix the installation shell to the patella position, under the action of the adjusting mechanism, the two measuring mechanisms can be easily adjusted and fixed to the designated position to measure the circumference of the lower limb, and the lower limb circumference measuring device is simple in overall structure, convenient to operate and high in practicability. And the measurement efficiency of the lower limb circumference can be greatly improved.

The invention discloses alloy steel 40Cr for a hot-rolled plate mechanical structure and a preparation method of the alloy steel 40Cr, the alloy steel 40Cr comprises the following components: 0.375-0.39% of C, 0.18-0.25% of Si, 0.55-0.65% of Mn, 0.010-0.040% of Al, 0.85-0.95% of Cr, less than or equal to 0.015% of P, less than or equal to 0.005% of S and the balance of iron and unavoidable impurity elements, the thickness of the alloy steel 40Cr for the hot-rolled plate mechanical structure is 2-16 mm, the width is 900-1500 mm, the yield strength is less than or equal to 500 MPa, the A-D type inclusions are less than or equal to 1.5, the DS type inclusions are less than or equal to 1.0, and the balance is Fe. A fully decarburized layer is not allowed to appear on the surface of the steel plate, the thickness of a single-face semi-decarburized layer is not larger than 1% of the nominal thickness, and the product is excellent in plate shape, roll shape, surface quality, machining performance and the like and is highly accepted by users.

The invention relates to the field of titanium alloy materials, in particular to an alpha + beta type easy-to-form high-strength titanium alloy containing active eutectoid elements and a preparation method. The titanium alloy comprises the following chemical components in percentage by mass: 5.0%-7.0% of an Al element, 2.0%-4.0% of an Nb element, 1.0%-3.0% of a Mo element, 1.0%-3.0% of a V element, 1.0%-2.0% of a Zr element, 3.0%-6.0% of a Cu element and the balance of Ti. Alpha + beta type easy-to-form high-strength titanium alloys with different strength levels are obtained according to the content of the Cu element, a nano Ti2Cu compound is rapidly formed at the eutectoid temperature by adding a high-activity eutectoid beta stable element Cu, the precipitation proportion of Ti2Cu is regulated and controlled by adjusting the content of Cu, and then the strength of the titanium alloy is regulated and controlled. The method can be widely applied to the important fields of aerospace, ocean engineering, weaponry, petrochemical engineering, automobile industry, biomedical treatment and the like.

This invention relates to a manufacturing process for stainless steel pipes, comprising the following steps: S1, raw material preparation; S2, heating and piercing; S3, hot rolling and stretching, controlling the grain size to grade 4-6; S4, pickling and grinding: shot blasting to remove oxide scale, followed by mixed acid (HNO₃+HF) pickling for 30-45 s, and finally local grinding, with defect depth ≤0.1 mm; S5, cold working; S6, solution treatment; S7, straightening and end cutting: ten-roll straightener, straightness ≤1 mm·m⁻¹; end cutting and tail trimming, with a 30° chamfer on the end face; in step S1, the EAF initial refining uses a "low carbon, low titanium" feedstock, with Ti controlled below 0.03% to reduce TiN nucleation; AOD uses a "double slag + strong bottom blowing" process, with CaO-CaF₂ slag basicity ≥2.5 and argon flow rate 0.15–0.20. The process involves Nm³·t⁻¹·min⁻¹, causing As, Sn, Pb, and Bi to enter the gas or slag phase, with the sum of the five low-melting-point elements ≤120 ppm. This invention utilizes gradient heating combined with low-stress piercing to prevent the low-melting-point harmful phase (Pb-Bi-Sn eutectic) from melting, reducing the piercing center crack rate from 4.1% to 0.25%, and achieving a first-pass yield of >99% in flaw detection.

The invention discloses a method for connecting a skutterudite thermoelectric material and an electrode by using a novel Al-containing high-entropy alloy diffusion barrier layer, and relates to the design and preparation of the diffusion barrier layer and the method for connecting the skutterudite thermoelectric material and the electrode. The method aims at solving the problems that diffusion cavities are huge due to unbalanced diffusion in a connector interface obtained through an existing skutterudite thermoelectric material welding method, and consequently a connecting connector is difficult to consider heat stability, interface resistance and mechanical performance at the same time. The method comprises the following steps: 1, cleaning a skutterudite thermoelectric material and an electrode; 2, preparing a diffusion barrier layer by using an electric arc melting or high-energy ball milling or rapid solidification method, and carrying out diffusion welding or brazing; and the diffusion barrier layer is made of an Al-Co-Cr-Fe-Ni system. The joint obtained by utilizing the novel Al-containing high-entropy alloy diffusion barrier layer can simultaneously have extremely low contact resistance, extremely high thermal stability and excellent mechanical properties. The method is suitable for connecting the skutterudite thermoelectric material and the electrode.

The invention relates to a production method of low-cost high-quality flux-cored wire steel, and belongs to the technical field of flux-cored wire steel production.The production method comprises the steps that after a steel variety is subjected to blast furnace molten iron smelting, molten iron desulfurization pretreatment, converter molten steel smelting, molten steel refining treatment and continuous casting blank forming, the finish rolling temperature of finish rolling is controlled to be 760-840 DEG C, the hot rolling laminar cooling mode is rear-section cooling, and the hot rolling temperature is controlled to be 760-840 DEG C; the curling temperature is controlled to be 630-670 DEG C; the deformation quantity is controlled between 60% and 75% through acid rolling treatment; the continuous annealing treatment is controlled as follows: the heating temperature is 820 + / -15 DEG C, the soaking temperature is 820 + / -15 DEG C, the slow cooling temperature is 670 + / -10 DEG C, the rapid cooling plate temperature is 450 + / -10 DEG C, and the cold rolling annealing time is greater than or equal to 3 minutes. By changing the finish rolling temperature, the cooling mode, the coiling temperature, the acid rolling process and the continuous annealing process, a flux-cored wire steel product with the large and uniform ferrite grain size, the yield strength smaller than 200 Mpa and the elongation larger than 48% is obtained.

The invention provides steel with high shock resistance, high strength and high toughness and a production method thereof. The steel comprises the following chemical components in percentage by mass: 0.14 to 0.20 percent of C, 0.10 to 0.30 percent of Si, 1.20 to 1.80 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.005 percent of S, 0.010 to 0.060 percent of Als, 0.010 to 0.035 percent of Nb and the balance of Fe and inevitable impurities. The production method comprises the steps of molten iron desulphurization, converter smelting, LF refining, slab continuous casting, continuous casting slab hot direct loading and heating, slab rolling, laminar cooling, coiling and forced cooling delivery. And the laminar cooling is front section sectional type cooling. By optimizing the chemical components of the steel and combining with an improved production process, especially a rolling and laminar cooling control process, energy conservation and emission reduction are achieved while the mechanical property and the machining and using performance of the steel are improved, and the production cost is reduced.

A method of manufacturing a fluid conduit comprising at least one tubular metal fitting in fluid communication with a metal pipe. The conduit is readily incorporated into a subsea umbilical. The fitting is made by cold forming a workpiece in a spinning operation. The workpiece material initially has a yield strength lower than the pipe material. The present invention corrects or reduces this mismatch between the yield strength of the pipe material and the initial yield strength of the workpiece material by: assessing the yield strength of the pipe material; assessing the increased yield strength of the workpiece material through the spinning operation; and comparing the increased yield strength of the workpiece material to the yield strength of the pipe material before welding the fitting to the pipe.