129results about How to "Guaranteed elongation" patented technology

The invention discloses an aluminium alloy conductor for automotive wires, which has the advantages of high heat resistance, conductivity, tensile strength, extensibility and fatigue resistance, and a manufacturing method thereof. The alloy contains 0.3 to 0.8 weight percent of iron, 0.05 to 0.20 percent of silicon, 0.1 to 0.5 weight percent of magnesium, 0.1 to 0.3 weight percent of copper, 0.001 to 0.04 weight percent of boron, 0.001 to 0.04 weight percent of zirconium, 0.001 to 0.04 weight percent of yttrium, and the balance of aluminium and inevitable impurities, wherein one or two elements, except the aluminium and the inevitable impurities, account for 0.1 to 2.0 weight percent. The manufacturing method comprises the following steps of: adding the iron, silicon, magnesium, copper, boron, zirconium, yttrium and aluminium into a smelting furnace; smelting, and casting and rolling; performing intermediate annealing treatment; drawing into aluminium alloy filaments with the diameterof 0.5mm; and stranding into wire cores, and performing annealing treatment. The conductor prepared by the method has the tensile strength of 210MPa and above, the elongation at break of over 10 percent, the conductivity of over 58 percent, and excellent heat resistance and flexibility.

The invention relates to a mixed additive for removing internal stress of an electrolytic copper foil and a method for producing a low-stress copper foil and belongs to the technical field of production of a high-precision electrolytic copper foil. The mixed additive for removing internal stress of the electrolytic copper foil comprises gelatin, hydroxyethyl cellulose and liquid additive. The method for producing the low-stress copper foil by using the mixed additive comprises the steps of preparing high-purity cathode copper and sulfuric acid into mixed solution of sulfuric acid and copper sulfate at 60-95 DEG C under the condition of stirring in the presence of air, wherein Cu<2+> is 85-100g/L and H2SO4 is 100-120g/L; adjusting the temperature of electrolyte to 45-60 DEG C and the flow to 50-70m<3>/h; adding 20-50mg/L of Cl<->, adding the mixed additive, with a drum titanium tube which continuously rotates as a cathode and arc titanium as an anode, carrying out copper electrolytic deposition and lastingly stripping to obtain 12-70 microns copper foil under the condition of the direct current of which the current density is 55-70A/dm<2>. The thickness of the copper foil is controlled by adjusting the rotation speed of the cathode; and the obtained copper foil has excellent performances.

The invention relates to a skin material for aviation, in particular to a machining method for preparing corrosion-fatigue-damage-resistant aluminum alloy plates, and belongs to the technical field ofnonferrous metals. The machining method comprises the steps that an aluminum alloy hot rolling material is subjected to solid solution treatment for the first time, then the second time of solid solution treatment is carried out after multi-pass cold rolling with the pass deformation amount being less than or equal to 1.0mm is carried out to achieve the design thickness of the aluminum alloy plate; and in the multi-pass cold rolling process, deep cooling treatment is carried out immediately after each pass of cold rolling, and the temperature of the deep cooling treatment is less than or equal to -100 DEG C. The machining method for preparing the corrosion-fatigue-damage-resistant aluminum alloy plates is reasonable in texture design, the preparation process is simple and controllable, obtained products have good performance, and the machining method for preparing the corrosion-fatigue-damage-resistant aluminum alloy plates is convenient for large-scale industrial application.

The invention relates to the technical field of nonferrous metals, and particularly relates to an aluminum alloy and a preparation method of the aluminum alloy. The aluminum alloy comprises the following components in percentage by weight: 8-10% of Zn, 2.5-3.5% of Mg, 2.3-3.5% of Cu, 0.05-0.25% of Zr, 0.01-0.10% of Sc; in the impurity elements, the content of Si being less than or equal to 0.1%, the content of Fe being less than or equal to 0.15%, each one in other elements being less than 0.05%, the total amount being less than 0.5%, and the balance of Al. With the adoption of the technical scheme, the content of Sc in the alloy is controlled reasonably, the content of Zr is enhanced, so the strength and the coefficient of elongation are ensured, and meanwhile the production cost of the alloy is reduced greatly; the tensile strength of the alloy is more than 750MPa, the yield strength is more than 700MPa, the coefficient of elongation is higher than 10%, so the alloy has excellent overall performance and is suitable for the light components requiring high strength.

The invention relates to a production technology of a copper-clad steel wire in a soft state. The production technology successively comprises the following steps: drawing; tempering under high temperature; carrying out electro-deposition pretreatment; carrying out acid electrolysis; washing; carrying out pretreatment of electro-deposition; washing; carrying out electrodeposition thick treatment; washing; carrying out anti-oxidation processing; drying; drawing; washing; carrying out anti-oxidation processing; tempering under high temperature; polishing; carrying out anti-oxidation processing; and spooling to obtain a finished product. An advantage of the production technology of the copper-clad steel wire in the soft state is that an elongation rate of the produced copper-clad steel wire is greater than or equal to 8%, wherein the elongation rate, which is compared with an elongation rate of a copper-clad steel wire produced by a traditional tempering technology, can be enhanced by at least more than one time..

The invention provides a flexible polyvinyl chloride (PVC) soft cable material which is prepared from the following component raw materials: by weight, 50-60 parts of PVC resin, 20-40 parts of polyester resin, 10-20 parts of organic silicone resin, 10-15 parts of precipitated white carbon black, 5-10 parts of wollastonite powder, 4-6 parts of dolomite, 4-6 parts of bauxite, 4-6 parts of molybdenum disulfide, 3-5 parts of pentaerythritol, 0.5-1.0 part of triphenyl phosphate, 0.1-0.2 part of antioxidant 1035, 0.1-0.2 part of antioxidant 168, 0.2-0.4 part of ferrocene, 0.1-0.3 part of stearic acid amide, 0.2-0.3 part of zinc stearate, 0.1-0.3 part of calcium stearate, 0.1-0.3 part of barium stearate, 0.1-0.2 part of phenyl methyl silicone oil and 10-15 parts of a modified filler. A plastic high mixing machine is used for mixing the formula components, after plasticizing granulation by use of a plastic extruding machine, the flexible polyvinyl chloride (PVC) soft cable material has excellent elongation and a greatly improved elastic property, and under the condition of ensuring product electrical performances, the elongation and tensile strength of a finished product can be improved.

The invention discloses an ethylene propylene rubber material for a sealing part of an automobile heat dissipation system and a production method of the ethylene propylene rubber material and belongs to the technical field of rubber. The rubber material is prepared from the following components in parts by weight: 100 parts of raw ethylene propylene rubber, 5 parts of zinc oxide, 0.5 to 1.5 parts of stearic acid, 3 to 6 parts of an anti-ageing agent, 20 to 30 parts of fast extruding carbon black N550, 10 to 20 parts of semi-reinforced carbon black N774, 3.5 to 7 parts of a cross-linking auxiliary agent Ricon 153D and 5 to 8.5 parts of a vulcanizing agent Perkadox 14-40B-GR. The rubber material disclosed by the invention has excellent high-temperature-resisting performance and can be used for a long time under the condition that the temperature is -50 DEG C to 150 DEG C; meanwhile, the rubber material has remarkable advantages of low temperature resistance and low-compression permanent deformation.

The invention discloses a preparation method of nano calcium carbonate for MS glue, which comprises the following steps: removing impurities from calcium hydroxide (Ca (OH) 2) slurry obtained after the digestion reaction of quicklime (CaO) and water (H2O), preserving heat and aging, adding a crystal form control agent, performing primary carbonization synthesis reaction with the washed kiln gas containing carbon dioxide (CO2), adding a post-treatment agent, aging for a certain time, performing secondary carbonization synthesis reaction with the washed kiln gas containing carbon dioxide (CO2) to obtain calcium carbonate (CaCO3) cooked slurry, adding a modifier into the cooked slurry, performing filter pressing dehydration, drying, crushing and grading after the reaction is finished to obtain the nano calcium carbonate for MS glue. The nano calcium carbonate crystal prepared by the method is a standard cube, and the crystal is mono-disperse, and the average particle diameter is only 100-150nm, and the specific surface area is 16-18m <2 >/g, and the nano calcium carbonate crystal is used for MS glue, and the thixotropy is good, and the extrusion property is good, and the storage stability is good, and the surface finish after gluing is good, and the tensile strength is high, and the elongation is high and the bonding property is also good. The preparation method of nano calcium carbonate for MS glue has the advantages of simple and feasible process, low cost, low price and better economic benefit.

The invention discloses a preparation method of a high-heat-conductivity type tire vulcanization capsule. The preparation method of the high-heat-conductivity type tire vulcanization capsule belongs to the technical field of tires, and comprises the following steps of (1) compounding the components according to the matching ratio: 95 parts of butyl rubber, 4 to 5 parts of chloroprene rubber, 15 to20 parts of N375 carbon black, 35 to 45 parts of acetylene black, 7 to 15 parts of graphene, 7 to 10 parts of alkane oil, 0.5 to 1.5 parts of stearic acid, 5 to 7 parts of zinc oxide, and 8 to 10 parts of resin; (2) primarily mixing; (3) filtering rubber; (4) secondarily mixing; (5) forming; (6) vulcanizing; (7) polishing; and (8) inspecting a finished product. According to the preparation methodof the high-heat-conductivity type tire vulcanization capsule provided by the invention, on the basis of ensuring the stability of various physical and mechanical properties, a heat conductivity coefficient is further improved, so that the aims of saving energy and reducing cost are achieved.

The invention belongs to the technical field of steel plate manufacturing and in particular relates to a hot galvanized steel plate and a preparation method thereof. In order to solve the problems that a hot galvanized steel plate prepared by an existing method is poor in mechanical property and stretching property and the like, the invention provides the hot galvanized steel plate and the preparation method thereof. The hot galvanized steel plate comprises the following chemical components in percentages by weight: less than or equal to 0.0030% of Cm 0.04-0.06% of Si, 0.10-0.20% of Mn, less than or equal to 0.010% of P, less than or equal to 0.008% of S, 0.010-0.020% of Ti, 0.025-0.050% of Als and the balance of Fe and inevitable impurities. The preparation method comprises the followingsteps: carrying out smelting, hot rolling, pickling rolling, hot galvanizing and annealing steps on smelted steel to prepare obtain the hot galvanized steel plate. The yield strength of the hot galvanized steel plate prepared by the invention is 180-240MPa, the tensile strength of the hot galvanized steel plate is 340-360MPa, the ductility is greater than or equal to 34.0%, n90 is greater than orequal to 0.18, r90 is greater than or equal to 1.6, BH is greater than or equal to 30MPa, and the hot galvanized steel plate is excellent in mechanical property and forming property and can meet the using demands of automotive planking users.

The invention relates to a construction method for prefabricating a directly-buried uncompensated centralized heat supply pipeline by electrically preheating. The method comprises the following steps of: (1) grooving, adjusting the coordinate and scale height of the heat supply pipeline, and computing the preheating temperature and the designed elongation of the heat supply pipeline; (2) controlling the sand refilling height at a half to three quarters of the pipeline height H; (3) connecting the same-side end of the heat supply pipeline with preheating equipment through a cable respectively, and short-circuiting the other side of the heat supply pipeline through a cable; (4) arranging temperature sensors on the heat supply pipeline respectively; (5) recording the initial temperature of the heat supply pipeline and the initial position of a measuring point, starting temperature raising, controlling the temperature raising gradient within 1 DEG C per hour, and preserving heat after a preheating temperature is reached; (6) refilling sand into both sides of the heat supply pipeline, tamping, and controlling the preheating temperature within the range of +/-2 DEG C; (7) after the designed elongation is reached, shutting down the preheating equipment; and (8) performing subsequent construction according to the steps (1)-(7). The construction method disclosed by the invention is safe, reliable, easy and practical, is easy for accurately controlling construction equipment, and is consistent with the national policy of energy saving and emission reduction.

The invention relates to the field of plastic steel, and specifically relates to a corrosion resistant plastic mould steel and a manufacturing method thereof. The plastic mould steel comprises following components in percentage by weight: 0.45 to 0.55% of C, 0.40 to 0.80% of Si, 0.80 to 1.60% of Mn, 0.10 to 0.25% of V, 0.007 to 0.015% of N, 0.005 to 0.050% of Al, not more than 0.035% of S, not more than 0.025% of P, 3.5 to 4.0% of Ni, 8.5 to 10.5% of Cr, 0.25 to 0.45% of Cu, and the balance being Fe and other impurities, which are introduced into the steel during the refining process, whereinCr+Ni=12-14.5%. The original strength, ductility, wear resistant performance, and cutting property of plastic mould steel are guaranteed, at the same time, the corrosion resistant performance of plastic mould steel is greatly improved; after polishing, the roughness is lower than that of products on the market; by controlling the using amounts of copper and molybdenum, the plastic mould steel canbe applied to different fields without influencing the performances of plastic mould steel, and the application range of plastic mould steel is enlarged.

The invention provides an Al-Mg-Si-Cu alloy which is high in strength and elongation. The Al-Mg-Si-Cu alloy comprises, by mass, 0.60-0.80% of Si, 1.05-1.15% of Mg, no more than 0.10% of Fe, 0.10-0.20%of Cu, 0.03-0.09% of Cr, no more than 0.05% of Mn, 0.05-0.12% of Zn, 0.01-0.04% of Ti, and the balance Al. The Al-Mg-Si-Cu alloy which is high in strength and elongation is designed through the reasonable proportion of the alloy components, the tensile strength of the prepared alloy material is 310MPa or over, the elongation is 18% or over, and the alloy material has good machinability such as the flanging performance and the turning performance.

The invention provides a high-strength wrought magnesium alloy containing rare earth neodymium and yttrium. The alloy comprises the following components in percentages by mass: 5.50-6.50wt.% of Zn, 0.47-0.80wt.% of Zr, 0.45-0.50wt.% of Nd, 0.72-1.00wt.% of Y, less than 0.10wt.% of inevitable impurities and the balance of Mg. A preparation method comprises the following steps: homogenizing a magnesium alloy ingot containing rare earth neodymium and yttrium, and then performing hot extrusion. Crystal grains are remarkably refined, meanwhile, neodymium, yttrium and elements such as magnesium andzinc in the alloy form second phases, and the second phases are re-crushed and distributed into fine dispersed strengthening phases in the hot extrusion process, so that growth of recrystallized crystal grains in the hot deformation process can be effectively hindered, a matrix is strengthened, and good mechanical properties can be obtained; and after hot extrusion, low-temperature aging treatmentis performed, so that the strength can be further improved, and the tensile strength after aging exceeds 400 MPa and is higher than that of most commercial magnesium alloys at present. The alloy is low in cost, a conventional smelting hot extrusion process is adopted, and the alloy has good operability and practicability and is convenient to popularize and apply.

The invention discloses a polyurethane fiber coating device used on an elasticizer which has low production cost and can directly finish composite coating of fiber filament on the elasticizer. The device comprises a proto-filament frame, a first guide pressing arm, a proto-filament roller, a molding frame, a pedestrian pedal and a stand, wherein the proto-filament roller is matched with the first guide pressing arm; a heating box is arranged on an input part for synthetic fiber filament between the molding frame and the stand; the stand is sequentially provided with a twister, a second guide pressing arm, a first tension roller, a polyurethane fiber drum, a traction roller, a composite filament deformation air spout, a third guide pressing arm and a second tension roller from top to bottom; the first tension roller is matched with the second guide pressing arm; and the second tension roller is matched with the third guide pressing arm.

The invention relates to a treatment method for a brass texture antifatigue aluminum alloy panel, which is characterized in that multiple times of warm rolling is performed on an aluminum alloy hot rolling material until reaching the designed thickness of the aluminum alloy panel, and after annealing treatment and solution treatment, short-term artificial aging is performed. According to the invention, a treatment process of multiple times of warm rolling and annealing is adopted; by virtue of warm rolling, grains of the alloy can be effectively refined, the return process of alloy can be promoted, deformation energy storage can be reduced, and recrystallization can be inhibited; and by virtue of primary annealing treatment, annealing temperature and heat insulation time can be controlled, grains cannot grow up, and a deformation texture can be retained, thus obtaining a relatively strong deformation texture. The treatment method is simple in process method and convenient to operate, can effectively improve the composition and the volume fraction of the texture in an aluminum alloy matrix, can effectively prolong the fatigue life of the aluminum alloy on the premise of ensuring that aluminum alloy strength and ductility meet alloy performance requirements, is suitable for industrial application, and provides a feasible technical solution for preparation of aluminum alloy material for aviation and spaceflight.

The invention relates to a special steel pipe for a CO2 (carbon dioxide) air conditioner compressor casing and a processing process of the special steel pipe. The processing method comprises the following process steps that steel coils are sheared into required steel belts according to specifications; the steel belts are subjected to leveling through a leveling machine after entering a machine unit production line, the smoothness is +/-0.30mm, and the two sides of the steel belts are respectively subjected to 60-degree planing and shaping; the welding current is regulated, and the current is controlled to be between 550A and 650A; the welding speed is controlled to be 30meter/minute to 35meter/minute; a heat affecting region is lengthened, and a welding opening angle is enlarged; the steel belts are formed into steel pipes by adopting a multi-roller extruding device; welding seams are formed at the welding points; the steel pipes are naturally cooled through air and are cooled through water after the welding, the steel pipes enter a correcting region, the roundness of the special steel pipes can be ensured, and the appearance dimension requirements are met. The special steel pipe and the processing process have the advantages that the roundness of the welding steel pipe casing and the tightness of the welding seams can be ensured, the welding seams can bear the maximum intensity pressure greater than or equal to 30Mpa, the production process is simple, the productivity can be improved, the manufacturing finished product rate is high, raw materials can be saved, the appearance is smooth and attractive, the quality can be improved, and the cost can also be reduced.

The invention discloses Nb-contained high-strength high-tenacity low-density steel for an automobile and a preparation method of the Nb-contained high-strength high-tenacity low-density steel for theautomobile, and relates to the field of metal materials. The Nb-contained high-strength high-tenacity low-density steel for the automobile comprise, by mass percentage, 0.9% to 1.1% of C, 9.4% to 9.7%of Al, 26.9% to 28.1% of Mn, 0.08% to 0.50% of Nb, smaller than 0.5% of Si, smaller than 0.004% of S, smaller than 0.003% of P, and the balance Fe and other inevitable impurity elements. According tothe Nb-contained high-strength high-tenacity low-density steel for the automobile, a finely dispersed NbC phase is precipitated by adding the Nb element to traditional Fe-Mn- Al-C low-density steel,the NbC phase and kappa-carbide jointly generate a precipitation strengthening effect, and then the high-strength high-tenacity low-density steel excellent in corrosion resistance is obtained, whereinaccording to the high-strength high-tenacity low-density steel excellent in corrosion resistance, the density is between 6.4 g/cm<3> - 6.7 g/cm<3>, the tensile strength is between 980 MPa and 1200 MPa, and the elongation percentage after fracture is between 20% and 50%, and the corrosion potential is larger than minus 0.462V. The Nb-contained high-strength high-tenacity low-density steel is suitable for automobile steel demands, can achieve lightweight of the automobile and meets the development concept of energy saving and emission reduction.

The invention discloses an aluminum magnesium alloy for casting castings with elongation of over 10 percent. The aluminum magnesium alloy comprises the following components in percentage by weight: 3.8 to 4.5 percent of Mg, 0.3 to 0.4 percent of Cu, 0.2 to 0.23 percent of Ti, less than or equal to 0.1 percent of Fe, less than or equal to 0.1 percent of Si and the balance of Al. All properties of the castings meet the requirement by effectively controlling the components of the aluminum magnesium alloy, wherein the control of the adding amount of the Ti is favorable for improving the plasticity and tenacity of the alloy, the reasonable adjustment of the component content of Cu and Mg can ensure that the elongation of the castings is over 10 percent so as to play a good role in solid dissolving strengthening on the alloy, and the strict control of Fe and Si elements belonging to impurities meets the requirement of casting and producing high-end mechanical parts.

The invention discloses a high-strength tin-plated raw plate and a manufacturing method thereof. The tin-plated raw plate comprises the following chemical components in percentage by weight: 0.08%-0.14% of C, 0.2%-0.5% of Mn, 0.03%-0.05% of Al, 0.01%-0.02% of P, 0.006%-0.015% of N and the balance Fe and Fe impurity elements, and the elements need to meet the following relationship simultaneously:50C+10Mn+50P+100N is not less than 8.5% and not greater than 12.75%. According to the manufacturing method disclosed by the invention, a one-step cold rolling process is adopted, an annealing temperature T in a continuous annealing step is controlled to be not less than 550+5*10<4>*(C-0.08%)+5x10<3>*(Mn-0.20%) and not greater than 630+5*10<4>*(C-0.08%), the unit is DEG C, and the tin-plated raw plate with a yield strength of not less than 500MPa and an elongation of not less than 5% after bake-hardening can be manufactured; and the manufacturing method is applicable to produce products with requirements on formability, such as three-piece can bodies, easy-open caps and twist-off caps.

A detection mechanism for an amorphous nanocrystalline iron core winding machine comprises an unwinding mechanism, two sets of flattening mechanisms, two sets of detection marking mechanisms, a winding mechanism and a rack. The flattening mechanisms are arranged side by side in a transverse direction, the detection marking mechanisms are symmetrically arranged in a longitudinal direction, and the unwinding mechanism, the detection marking mechanisms and the winding mechanism are sequentially arranged in the transverse direction. Each flattening mechanism comprises two flattening rollers arranged side by side in the vertical direction and a distance adjusting mechanism used for adjusting the distance between the two flattening rollers. The detection marking mechanism comprises a roller, a mounting shaft, a moving frame, an ink immersion box, ink absorption cotton, a marking pen point, a first sliding rod, a first elastic piece, a second sliding rod, a second elastic piece, a first connecting ring, a connecting rope, a second connecting ring, a fixing plate, a push rod, a sliding plate, a third elastic piece and an ink supply mechanism used for supplying ink to the ink absorption cotton. According to the invention, the flatness of the edge of an iron core steel strip can be rapidly and effectively detected, and corresponding marking is carried out.

The invention belongs to the technical field of steel plate manufacturing, in particular to a hot-dip galvanized steel plate and a preparation method thereof. In order to solve the problems that the hot-dip galvanized steel plate prepared by an existing method is poor in mechanical property, is not good in extension property and the like, the invention provides the hot-dip galvanized steel plate and the preparation method thereof. The hot-dip galvanized steel plate is prepared from the following chemical components in percentage by weight: 0.04-0.08% of C, 0.01-0.04% of Si, 0.10-0.40% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.015-0.050% of Als, 0.0010-0.0040% of B and the balance of Fe and inevitable impurities. The preparation method for the hot-dip galvanized steel plate comprises the following steps: performing processes of smelting, hot rolling, acid rolling, hot-dip galvanizing and annealing on smelting molten steel, thereby obtaining the hot-dip galvanized steel plate. The hot-dip galvanized steel plate prepared by the preparation method has yield strength of 220-250 MPa, tensile strength of 320-380 MPa, elongation percentage greater thanor equal to 36.0%, n90 greater than or equal to 0.18, r90 greater than or equal to 1.5, BH greater than or equal to 30 MPa, and excellent mechanical properties and forming properties, and can meet using requirements of an automobile outer panel user.

The invention discloses a floor slab damage avoiding type double-beam self-resetting anti-seismic steel framework which comprises at least one structural unit. Each structural unit comprises two framework columns, an upper I-shaped steel beam and a lower I-shaped steel beam, wherein the upper I-shaped steel beam and the lower I-shaped steel beam are in vertically adjacent arrangement, two ends ofthe upper I-shaped steel beam are connected with the framework columns through upper flange steel plates, two ends of the lower I-shaped steel beam are connected with the framework columns through lower flange steel plates, a gap is reserved between the upper I-shaped steel beam and the lower I-shaped steel beam, two ends of the upper I-shaped steel beam and the lower I-shaped steel beam are connected into a whole through end limiting devices, pre-tensioning rods are anchored between the end limiting devices at two ends, shear connectors are arranged on webs of the upper I-shaped steel beam and the lower I-shaped steel beam, and ends of the shear connectors are welded to the framework columns. The floor slab damage avoiding type double-beam self-resetting anti-seismic steel framework has advantages that self resetting of steel structures in small earthquakes and intermediate earthquakes can be realized, structural damages in severe earthquakes are avoided, floor slab pull cracks are avoided due to a self-resetting mechanism, and accordingly post-earthquake economic loss is effectively reduced.

The invention relates to medium-carbon low-cost L245-L320-grade pipeline steel and a manufacturing method thereof. The pipeline steel comprises the following chemical components by mass percent: 0.14 to 0.18% of C, 0.1 to 0.3% of Si, 0.5 to 0.7% of Mn, 0.005% or less of S, 0.015% or less of P and 0.02 to 0.06% of Al, and the balance being iron and unavoidable impurities. The technological process comprises the steps of KR, converter smelting, deoxidation alloying, CAS, LF, VD/RH, continuous casting, 48 hours of casting blank stacking and cooling, casting blank heating, scale removal, rough rolling, finish rolling, ACC, straightening, cooling, flaw detection, and marking and storage. According to the medium-carbon low-cost L245-L320-grade pipeline steel and the manufacturing method thereof, the content of carbon elements is increased, the utilization amounts of V, Ti and Nb are decreased, the alloy cost is effectively reduced, the fineness degree and uniformity of the structure of a product are improved, and the production flexibility of the manufacturing method is high.