40results about How to "Make up for loss of strength" patented technology

The invention provides tensile strength more than or equal to 780MPa grade hot-rolled dual phase steel. The dual-phase steel comprises the following components in percentage by weight: 0.05-0.08 percent of C, not more than 0.5 percent of S, 0.6-1.2 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.006 percent of N, 0.01-0.1 percent of Als, 0.05-0.25 percent of Ti, less than or equal to 0.6 percent of Cr or less than or equal to 0.003 percent of B or mixture of Cr and B. The production method by using CSP comprises the following steps: melting and continuously casting to form a slab; heating the continuous cast slab; rolling; carrying out laminar cooling; reeling; and naturally cooling to room temperature. The hot-rolled dual phase steel has the tensile strength of more than or equal to 780MPa, elongation of more than or equal to 15 percent and yield ratio of less than or equal to 0.70. An insulation cover additionally covers the intermediate insulation section, and the band steel cooling speed is reduced, so that generation of pearlite phase change can be effectively prevented. Production of hot-rolled dual phase steel with thickness of 1.2-4.0mm can be realized, the product has the advantages of uniform structure, small molding resilience and no cracking, existing equipment is utilized without adopting ultra fast cooling and other equipment, the production efficiency is high, and the investment is small.

The invention provides Cu-containing nanophase strengthened easy-to-weld steel and a preparation method. The Cu-containing nanophase strengthened easy-to-weld steel comprises the following components by weight percent: less than 0.05% of C, 0.1-0.3% of Si, 0.5-1.5% of Mn, less than 0.002% of S, less than 0.004% of P, 1.5-2.5% of Cu, 4-8% of Ni, 0.3-0.8% of Al, 0.2-1% of Mo, less than 1% of Cr, 001-0.04% of Nb, 0.01-0.05% of Ti, 0.01-0.08% of V, and the balance of Fe and inevitable impurity elements. The preparation method comprises the following steps: performing induction smelting and casting under argon protection; heating cast ingots at 1,100-1,200 DEG C for 1-3 h, directly performing hot rolling at the initial temperature of 1,050-1,150 DEG C and the final temperature of 950 DEG C, and performing super-speed high-pressure water cooling after final rolling, wherein the hot rolling deformation is 50-90%; and selectively conducting solution and aging heat treatment on a rolled steel plate to obtain high-strength high-toughness easy-to-weld steel. The alloy steel is high in strength, good in plasticity, excellent in low-temperature impact toughness and easy to weld. Besides, the machining process is high in controllability, the cost is low and the operation is simple.

The invention discloses Al-Mg-Si-Cu alloy and a preparation method thereof. The alloy consists of the following components in percentage by mass: 0.4 to 0.6 percent of Mg, 0.45 to 0.6 percent of Si, 0.3 to 0.8 percent of Cu, 0.1 to 0.2 percent of Mn, 0.1 to 0.7 percent of Zn, 0 to 0.1 percent of Cr, 0.01 to 0.02 percent of Ti, not more than 0.3 percent of Fe, not more than 0.1 percent of other impurities (total content), and the balance of Al. The alloy has the characteristics of the reduction of deformation resistance, improves extrusion speed and production efficiency, and can improve the yield under the condition of constant productivity. In addition, the alloy does not need an extra water quenching process, and can reduce investment cost of equipment by on-line air quenching after hot extrusion.

The invention provides a circular steel tube constraining reinforced concrete-steel beam framework node for a nodal-region composite steel tube. The node comprises a first columnar circular steel tube, a second columnar circular steel tube, columnar longitudinal bars, columnar stirrups, a steel beam, a nodal-region inner-layer circular steel tube, a nodal-region outer-layer circular steel tube, outer reinforcing rings, nodal-region stirrups and concrete. The second columnar circular steel tube and the first columnar circular steel tube are located on the upper side and the lower side of the steel beam respectively. The steel beam directly transmits the shear force and the bending moment to the nodal-region inner-layer circular steel tube and then transmits the shear force and the bending moment to the core-region concrete, the condition that the nodal-region outer-layer steel tube directly bears the shear force is avoided to prevent the steel tube from being bent, and therefore the steel tube can fully play an annular constraining role to ensure the bearing capacity and the ductility of the node; the two ends of the nodal-region inner-layer circular steel tube stretch into an upper steel tube constraining reinforced concrete column and a lower steel tube constraining reinforced concrete column by a certain distance respectively, the integrity of the node is guaranteed, and the shear capacity and anti-seismic performance of the node are improved. The node is safe, reliable, good in integrity, clear in force transmission and convenient to construct and has the advantage on force bearing and the economic performance.

The invention discloses vanadium-microalloyed hot-rolled transformation induced plasticity steel with a grade above 1000MPa and a preparation method. The hot-rolled transformation induced plasticity steel comprises the following components by mass percent: 0.18-0.23% of C, not more than 0.50% of Si, 1.0-1.5% of Mn, 0.16-0.20% of V, 0.01-0.03% of N, not more than 0.06% of P, not more than 0.005% of S and the balance of Fe and other inevitable impurities. Through reasonable component design and process control, the tensile strength is not less than 1000MPa, the elongation at break is not less than 22.0%, the yield ratio is not more than 0.69, the work hardening index is not less than 0.22, the hole expansion rate is not less than 90%, the volume fraction of residual austenite in microscopic structures is not less than 12.0%, and fine V (C, N) precipitated particles with diameters of 2-5nm are diffusely distributed in a matrix.

The invention relates to a high-durability concrete product with a gradient structure, and a preparation method thereof. The preparation method comprises the following steps: 1) mixing for obtaining concrete: mixing a dense admixture for substituting a part of a cementing material to obtain the concrete; 2) pouring the concrete into a mold, molding the concrete, and curing and demolding the moldedconcrete to obtain a concrete test piece; and 3) drying the surface of the concrete test piece, carrying out carbonization curing on the dried concrete test piece in an autoclave in a carbon dioxideatmosphere, and then carrying out standard curing to obtain the high-durability concrete product with the gradient structure. The gradient structure which gradually densifies from the inside to the outside is formed on the surface of the concrete test piece through the carbonization curing treatment, and the surface carbonized dense layer can improve the corrosion resistance of the concrete material and prolong the service life; and the outer layer has a high strength, so the confinement effect is formed, thereby the deformation resistance of the test piece is improved, and the hardening of the concrete test piece is accelerated.

The invention provides a compound type concrete foaming agent, a preparation method and an application thereof. The compound type concrete foaming agent is prepared by compounding a component A and acomponent B, wherein the component A comprises 10-20 parts of polyvinyl alcohol, 15-25 parts of colophony, 1.5-2.5 parts of anhydrous sodium carbonate, 3.5-4.5 parts of industrial sodium hydroxide, 3-5 parts of triethanolamine, 0.2-0.5 parts of industrial grade hydrochloric acid and 53.5-55.8 parts of water; and the component B comprises 0.2-0.5 parts of triethanolamine, 8-10 parts of sodium sulfate, 12-15 parts of sodium nitrite, 10-25 parts of calcium chloride and 54.7-64.5 parts of water. The compound type concrete foaming agent not only can increase the doped quantity of the foaming agentbut also can compensate the concrete strength and the solidification time; the compound type concrete foaming agent can be used for manufacturing foam concrete with super-low capacity, also utilize alarge amount of waste residues, such as industrial and architectural rubbish and the like, to produce light foamed concrete.

The invention relates to low-cost production process for a Q355C steel plate. The Q355C steel plate comprises the following chemical components in percentage by mass: 0.11%-0.20% of C, not greater than 0.20%-0.45% of Si, 1.1%-1.6% of Mn, 0.015%-0.045% of Alt, not greater than 0.025% of P, not greater than 0.015% of S and the balance Fe; the internal quality of the steel plate is improved via converter smelting, reasonable end-point carbon content control, complete deoxygenation, white slag refining and soft blowing, calcium treatment, and continuous casting; and the internal quality of the steel plate is further improved through rough rolling and finish rolling two-phase controlled rolling, and reasonable allocation for rolling temperatures, speeds and passes. According to the low-cost production process for the Q355C steel plate, the impact toughness at 0 DEG C is improved by reducing a C content; expensive Nb and V are replaced by cheap micro-alloy element Al, so that the profit maximization is realized, and the impact toughness is further improved; and the Q355C steel plate is produced through a rolling process which is matched with the components, and the cost of a ton of steelcan be reduced by 50 yuan.

The invention discloses 800 MPa grade cold-rolling dual-phase steel and a manufacturing method thereof. The steel contains the following chemical compositions in percentage by weight: 0.10-0.18% of C, 0.03-0.19% of Si, 2.6-3.0% of Mn, 0.01-0.04% of Als, 0.15-0.9% of Cr, and the balance of Fe and other inevitable impurities. The manufacturing method for the steel comprises the following steps sequentially: heating billet steel to 1150-1250 DEG C along with a furnace and preserving the temperature for 1.5-3 hours under heat insulation condition, then performing hot rolling, wherein the rough rolling start rolling temperature is controlled within the range from 1050 DEG C to 1110 DEG C, the precision rolling finish rolling temperature is controlled within the range from 860 DEG C to 900 DEG C, and the simulation curling temperature is controlled within the range from 560 to 600 DEG C; washing a hot rolled plate with acid and then carrying out cold rolling; wherein the cold rolling pressing rate is controlled to be 45-75%, then performing the annealing treatment, wherein the annealing temperature is controlled within the range from 760 DEG C to 860 DEG C; and slowly cooling the hot rolled plate to 630-680 DEG C after keeping for 1-5 minutes under heat preservation condition and then rapidly cooling to be below 350 DEG C at a speed more than 25 DEG C/s for ageing treatment lasting for 5-10 minutes. The practice proves that the steel has the advantages of low yield strength, low yield ratio, high coefficient of elongation, and excellent forming property, and the manufacturing method has simple process and low cost.

The invention discloses a microwave-dipping modifying treatment process for wood of a solid wood ground heating floor. The treatment process comprises a, microwave treatment: placing the wood in a microwave treatment device for performing microwave treatment, wherein the microwave treatment process is divided into 3 times, and the treatment every time has a time interval of 1-3min; adjusting radiation power to 2-5KW for the first time, wherein the radiation time is 30-60s; adjusting the radiation power to 1-4KW for the second time, wherein the radiation time is 20-40s; adjusting the radiation power to 0.2-0.8KW for the third time, wherein the radiation time is 8-15s; b, cooling; performing cooling and temperature reduction, taking the wood out of a tank after the temperature is reduced to 25-40 DEG C; c dipping for the first time: dipping the wood in an analysis pure water solution with a mass percent of 20-30%, wherein a dipping temperature is 50-70 DEG C; taking out for drying after dipping for 25-35h, and drying till a water content is 8%; d, dipping for the second time: placing the well-dried wood in a vacuum dipping tank, adjusting a vacuum degree to -0.20 to (-0.10)MPa, keeping for 10-20min, using negative pressure to inject resin into the tank body so as to dip the wood in the resin, and controlling a pressure to be 1-3MPa and keeping for 1-4h; and e: obtaining a finished product: drying to obtain the final material.

The invention provides a Q345D steel with a thickness of 16 mm and a production method thereof. The Q345D steel comprises the following elements by mass: 0.14 to 0.18% of C, 0.90 to 1.03% of Mn and 0.012 to 0. 020% of Nb. In the process of production, the surface temperature of a casting blank at the ending moment of heating is controlled within the range of 1100-1150 DEG C, heating time is no less than 8 min/cm; an initial rolling temperature is 1080-1100 DEG C, a first-stage finish rolling temperature is more than 1000 DEG C, and a second-stage finish rolling temperature is no more than 890DEG C; in the second stage, the temperature-waiting thickness of the casting blank 2.5 times or more the thickness of a finished steel sheet, and the finish rolling temperature is controlled within the range of 810 to 850 DEG C; an initial cooling temperature is no less than 740 DEG C, and a finish cooling temperature is 650+/- 20 DEG C. The production method of the invention successfully producesthe Q345D low-alloy high-strength steel under the premise of ensuring low production cost, and the mechanical properties and internal quality of the produced steel plate meet requirements prescribedin GB/T1591.

The invention relates to a glass fiber net reinforcement part, an exterior wall heat-preservation anti-cracking structure and a construction method of the exterior wall heat-preservation anti-cracking structure. The glass fiber net reinforcement part is of an integral sheet structure formed by two fixing sheets with the same shape and a connecting bridge connected between the two fixing sheets, and a threaded hole penetrating through a screw is formed at the center position of the fixing sheet. In addition, the glass fiber net reinforcement part is designed to be used for reinforcing the connecting strength of an anti-cracking mortar layer and a heat preservation layer, the glass fiber net reinforcement part has a simple structure, has low cost, can be constructed conveniently, and has a good fixing effect, can compensate the strength loss when the binding power between the anti-cracking mortar layer and the heat preservation layer is low, and can ensure the bonding quality and the construction reliability of the follow-up surface layer, the construction operation is simple, the construction difficulty is not increased, the original construction quality and the construction efficiency are not influenced, the using amount of the anti-cracking mortar can be used to a certain extent, the cost is reduced and the glass fiber net reinforcement part can be widely applied to exterior wall construction.

The invention particularly relates to a high-temperature-resistant sleeve grouting material for steel bar connection, which comprises a component A and a component B. The component A comprises 20-30%of Portland cement, 3-5% of high-alumina cement, 2-3% of S95 mineral powder, 1-2% of silica fume, 5-10% of fly ash, 5-10% of quartz sand fine powder, 0.5-1% of expanding agent, 1-2% of copolyoxymethylene fiber, 20-30% of magnesite fine aggregate with a fineness modulus of 2.7, and 10-20% of blast furnace steel slag fine aggregate subjected to high-temperature autoclaving treatment, and the like. The component B comprises the following components in percentage by weight: 4-10% of water, 0.01-0.02% of graphene oxide, 2-3% of polycarboxylic acid water reducing agent mother liquor, 1-2% of polycarboxylic acid slump retaining mother liquor, 0.03-0.1% of air entraining agent and 0.03-0.1% of defoaming agent. The sleeve grouting material forms a steam dissipation channel in the grouting sleeve and maintains high mechanical properties, so that structural burst of a steel bar connecting joint is avoided, and secondary disasters can be avoided.

The invention is suitable for the technical field of steel wire rod machining, and provides a chromium alloy non-quenched and tempered steel wire rod and a production method thereof. The chromium alloy non-quenched and tempered steel wire rod comprises the following chemical components of, by weight, 0.22-0.31% of C, 1.20-1.55% of Mn, 0.15-0.30% of Si, 0.30-0.40% of Cr, less than or equal to 0.012% of P, less than or equal to 0.008% of S; less than or equal to 0.05% of Ni, less than or equal to 0.05% of Cu, less than or equal to 0.03% of Mo, less than or equal to 0.003% of Al, less than or equal to 0.002% of Ti, less than or equal to 0.002% of O, less than or equal to 0.005% of N, 0.05-0.20% of V, and the balance Fe and inevitable impurities. According to the method, the carbon content isreduced, the manganese content is reduced, the carbon segregation of the wire rod is improved, the plasticity of the wire rod is slightly improved, the forming probability of net carbon is reduced bycombining high-temperature rolling and controlled cooling processes, and the user machining wire breakage rate is reduced, so that the production efficiency of the user is improved; and in the coolingprocess, the process design of proper quick cooling and then slow cooling is adopted, growth of grains is controlled, ferrite-pearlite zonal segregation is reduced, and meanwhile, the situation thatthe cold working performance is deteriorated due to too high strength caused by an abnormal quenching structure is avoided.

The invention relates to a method for testing the value of bonded prestress released after pre-reinforcement of an existing structure, and belongs to the technical field of prestress measurement in civil engineering, the device comprises a concrete structure body, bonded prestressed tendons, a first strain gauge, a second strain gauge, a third strain gauge and a fourth strain gauge, at least one first strain gauge is bonded on the bonded prestressed tendon and is bonded along the prestressed direction; the carbon fiber sheet is adhered to the surface of the bonded prestressed tendon, and the carbon fiber sheet is adhered to one side opposite to the cutting device; the bonded prestressed tendons are pre-reinforced by the carbon fiber sheets; and the second strain gauge is bonded on the carbon fiber sheet and is bonded along the pre-stress direction. The method has the advantages that the prestress value can be accurately measured, and the strength of the prestressed tendon cannot be greatly weakened.

The invention relates to ultralow-carbon high-strength high-plasticity martensitic steel and a preparation method thereof, and belongs to the field of steel preparation. The martensitic steel comprises the following chemical components in percentage by mass: 0.01-0.05% of C, 0.2-0.5% of Si, 0.5-0.8% of Mn, 0.8-1.2% of Cr, 2.0-4.0% of Cu, 10.0-11.0% of Ni, 0.05-0.15% of V, 0.5-0.9% of Mo, 0.2-0.5% of Al, less than or equal to 0.02% of P, less than or equal to 0.02% of S and the balance of Fe. The elements of Cu, Ni, Al and Mn are added into the alloy, and Cu and Ni3Al (Mn)-rich phases can be separated out in the aging heat treatment process, so that the high strength of the alloy is achieved, and meanwhile the welding performance is excellent. The martensitic steel does not need rolling, subzero treatment and the heat treatment process are simple, the production efficiency is high, and implementation is easy.

The invention provides a macromolecular gypsum retarder and a preparation method and application thereof, and the macromolecular gypsum retarder comprises the following raw materials: polyepoxysuccinic acid, polyaspartic acid and a polycarboxylate superplasticizer. The invention also provides a preparation method of the polymer gypsum retarder and application of the polymer gypsum retarder. The polymer gypsum retarder provided by the invention can realize efficient retarding in the gypsum slurry hardening process, reduces the water consumption, improves the strength, and effectively solves theproblem of gypsum strength reduction caused by retarding.