1569results about How to "Reduce segregation" patented technology

The invention discloses a processing method for a TC4 titanium alloy large-sized bar. The method comprises the following steps of: cogging and forging TC4 titanium alloy ingots for 2 to 3 heating times to obtain forging billets; 2, upsetting the forging billets repeatedly and performing drawing-out forging for 2 to 3 heating times; 3, upsetting the forging billets subjected to forging repeatedly and performing drawing-out forging for 3 to 5 heating times; and 4, performing chamfering round forging on the forging billets subjected to forging for 2 heating times to obtain the TC4 titanium alloy large-sized bar with the diameter of 200 to 400 mm and length of not less than 2,500 mm. The TC4 titanium alloy bar processed by the method has uniform and fine grains, few internal defects and high safety and accords with the domestic advanced level of the like products. In the processed TC4 titanium alloy bar, the room-temperature tensile strength is 920 to 960 MPa; the yield strength is 830 to 870 MPa; the elongation percentage is not less than 12 percent; the contraction ratio of the cross section is not less than 36 percent; flaw detection clutter reflects small signals; and the flaw detection level is high.

The invention discloses a superhigh-strength high-toughness steel plate for ocean engineering and a manufacturing method thereof. The superhigh-strength high-toughness steel plate comprises the following chemical components in percentage by weight: 0.06-0.10% of C, 0.20-0.40% of Si, 1.10-1.65% of Mn, at most 0.010% of P, at most 0.0020% of S, 0.030-0.050% of Nb, 0.020-0.060% of V, 0.006-0.015% of Ti, 0.60-1.30% of Ni, 0.30-0.60% of Cr, 0.20-0.60% of Cu, 0.40-0.60% of Mo, 0.020-0.040% of Alt, and the balance of Fe and inevitable impurities. The production method comprises the following steps: smelting in a converter, rolling on a Steckel reversing mill, and finally carrying out hardening and tempering heat treatment by a TMCP (thermomechanical rolling process) technique. The steel plate has favorable properties: the tensile strength is 770-840 MPa, the yield strength is 710-800 MPa, the elongation percentage is 16-19%, the -40 DEG C low-temperature lateral impact and low-temperature ageing impact properties are greater than or equal to 90J, and the cold bending resistance is qualified; and thus, the steel plate has the advantages of ultrahigh strength, excellent low-temperature impact and low-temperature ageing impact properties, and stable production technique.

The invention discloses an electromagnetic current coupling field assisted hybrid melting-brazing method for a laser-TIG arc and equipment. In addition to the use of the welding zone, an alternating magnetic field is added to control properties of plasma formed through ionization of laser, arc and a raw material metal, thereby improving the laser utilization rate. Under the electric field assisted comprehensive effect, the weld melting depth is increased, and the assistant effect on the melting bath of the liquid-state brazing filler metal for laser-arc melting-brazing is realized through electromagnetic stirring and excitation and enhancement, thereby promoting the orderly flow of the liquid-state brazing filler metal and the rupture, wetting, spreading and proliferation of the liquid-state brazing filler metal on the surface of the high metal material, improving the full mixing of the liquid-state brazing filler metal and the base metal formed by melting the low-melting-point metal material, improving the uniformity of the components of the brazed weld, stabilizing the welding process, reducing welding defects, increasing the welding speed, improving the weld formation, optimizing the structure and performance of the brazed weld, and improving the quality of the brazed joint. Moreover, the equipment has the advantages of simple structure, flexible application, low cost, good effect and easy realization.

The invention relates to boracic high chromium wear resistant cast iron and a preparation method thereof, belonging to the wear resistant metal material technical field. The prior boracic high chromium cast iron has poor toughness and high cost. The cast iron of the invention comprises the following compositions in percentage by weight (wt percent): 2.5 to 3.5 percent of carbon, 15 to 28 percent of chromium, 0.5 to 1.2 percent of silicon, 0.5 to 1.2 percent of manganese, 0.15 to 0.3 percent of boron, 0.008 to 0.03 percent of calcium, 0.03 to 0.08 percent of barium, 0.02 to 0.05 percent of strontium, 0.03 to 0.08 percent of aluminum, 0.20 to 0.5 percent of titanium, 0.02 to 0.06 percent of lanthanum, 0.02 to 0.06 percent of cerium, less than 0.04 percent of sulfur, less than 0.05 percent of phosphor, the balance being iron; the content of lanthanum and cerium is more than or equal to 0.05 percent and less than or equal to 0.1 percent; the content of chromium or carbon is more than or equal to 6 percent and less than or equal to 8 percent. In the invention, the temperature of cast iron is kept between 980 DEG C and 1050 DEG C for 4h to 6h, then kept between 250 DEG C and 500 DEG C for 8h to 10h, thereby obtaining the cast iron. The boracic high chromium wear resistant cast iron has the advantages of high intensity and rigidity, good toughness and wear resistance, low production cost, etc.

The X65 pipeline steel for use in acid condition consists of C 0.02-0.05 wt%, Mn 1.20-1.50 wt%, Si 0.10-0.50 wt%, S not more than 0.0020 wt%, P 0.004-0.012 wt%, Nb 0.05-0.07 wt%, Ti 0.005-0.025 wt%, Mo 0.050-0.195 wt%, Cu not more than 0.35 wt%, Ni not more than 0.35 wt%, N not more than 0.0080 wt%, Ca 0.0015-0.0045 wt% and Ca/S not less than 2.0 except Fe. Its making process includes the following steps: smelting in a converter or an electric furnace; secondary steel making including LF desulfurizing + RH vacuum deairing and Ca treatment; continuous casting; rolling with initial rolling termination temperature of 940-1020 deg.c and finish rolling termination temperature of 780-840 deg.c; and winding at 500-580 deg.c. The X65 pipeline steel has low manufacture cost, high HIC resistance, high dynamic tear resistance and high impact toughness.

The invention discloses high-toughness medium-carbon quenched and tempered round steel of the grade 120 KSI. The high-toughness medium-carbon quenched and tempered round steel of the grade 120 KSI comprises, by mass, 0.35%-0.50% of C, 0.15%-0.40% of Si, 0.60%-1.30% of Mn, equal to or less than 0.015% of P, equal to or less than 0.040% of S, 0.75%-1.30% of Cr, 0.15%-0.35% of Mo, equal to or less than 0.25% of Ni, equal to or less than 0.25% of Cu, 0.015%-0.040% of Alt, equal to or less than 0.10% of V, equal to or less than 0.10% of Nb, equal to or less than 0.05% of Ti, equal to or less than 0.008% of N, equal to or less than 0.0010% of B and the balance Fe and unavoidable impurity elements, wherein the content of V, the content of Nb and the content of Ti are not equal to or less than 0.010% at the same time. The round steel with the maximum specification reaching 260 mm is manufactured through Kanbara reactor (KR) pretreatment, basic oxygen furnace (BOF) smelting, ladle furnace (LF) refining, Ruhrstahl Heraeus (RH) vacuum degassing, continuous casting, heating, continuous rolling, and hardening and tempering, so that the requirements for high specifications and toughness are met.

The present invention belongs to the field of steel-smelting technology. The steel consists of C 0.30-0.43 wt%, Mn less than 0.60 wt%, Si 0.70-1.00 wt%, P less than 0.010 wt%, S less than 0.007 wt%, Cr 4.50-5.50 wt%, Mo 1.00-1.50 wt%, V 0.7-1.00 wt%, Nb 0-0.25 wt%, Al less than 0.015 wt%, Ni 0.10-0.75 wt%, Cu less than 0.10 wt%, O less than 30 ppm and H less than 2 ppm, except Fe. It may contain one or several of RE, W, B, Ca, Mg, Zr and Ti. The steel of the present invention has reasonable production process, high performance and long service life of the core rod therewith.

The heat insulating mortar powder contains cementing material, foamed modified polystyrene grain, modified expanded pearlite, cementing material modifier and fiber. The foamed modified polystyrene grain contains foamed polystyrene grain, foamed polystyrene modifier and flyash; the modified expanded pearlite contains expanded pearlite, expanded pearlite modifier and sodium hydroxide; and the cementing material modifier contains polymer adhesive, air entraining and water reducing agent and flyash activator. The preparation process includes preparing foamed modified polystyrene grain, preparing modified expanded pearlite, preparing cementing material modifier, and mixing all the materials in certain proportion. The present invention has the advantages of small heat conducting coefficient, high compression strength, good construction performance, high adhering strength, etc.

The invention relates to steel for ocean engineering and a manufacturing method thereof, in particular to a steel plate with a thickness of 80mm and a low compression ratio for ocean engineering and a manufacturing method thereof. The steel plate comprises the chemical components with the weight percentages as follows: 0.12 to 0.16 percent of C, 0.20 to 0.40 percent of Si, 1.20 to 1.60 percent ofMn, smaller than or equal to 0.010 percent of P, smaller than or equal to 0.003 percent of S, 0.025 to 0.050 percent of Nb, 0.030 to 0.050 percent of V, 0.010 to 0.020 percent of Ti, smaller than or equal to 0.20 percent of Cr, 0.10 to 0.40 percent of Ni, smaller than or equal to 0.20 percent of Cu, smaller than or equal to 0.08 percent of Mo, 0.0250 to 0.050 percent of Al, smaller than or equal to 20ppm of O, smaller than or equal to 40ppm of N, smaller than or equal to 3ppm of H, and the remaining amount of Fe and inevitable impurities. A controlled rolling and cooling technology is adopted, the heating temperature before rolling is 1180 DEG C to 1250 DEG C, the rough rolling temperature is 1000 to 1100 DEG C, and the finish rolling starting temperature is 850 to 880 DEG C; laminar cooling is conducted after the rolling, the final cooling temperature is 640 to 680 DEG C, and the cooling rate is 5 to 15 DEG C/s; and normalizing treatment is conducted, the normalizing temperature is 890 to 910 DEG C, the heating rate is 1.4min/mm, and the heat preservation time is 50 to 90min. The obtained steel has the characteristics of high strength, good Z-direction lamellar tearing resistant performance, high plasticity, and the like.

The invention belongs to the field of preparation of magnesium alloy biological medical materials and particularly relates to a Mg-Zn-Y-Nd alloy for biodegradable vascular stents and a preparation method thereof. The Mg-Zn-Y-Nd alloy comprises the following components in percentage by weight: 1 to 3 percent of Zn, 0.23 to 0.69 percent of Y, 0.5 to 1 percent of Nd and the balance of Mg, wherein the weight percentage content of Zn and the weight percentage content of Y meet a condition that the molar ratio of Zn to Y is kept at 6:1 constantly and the weight percentage content ratio of Y to N is smaller than 1. The preparation method comprises: preparing charging materials according to the composition of the Mg-Zn-Y-Nd alloy and the condition that the weight percentage content of the Zn and the weight percentage content of Nd is 20 to 30 percent more than those required, and smelting to obtain common Mg-Zn-Y-Nd alloy, wherein the charging materials of Mg, Zn, Y and Nd are high-purity magnesium ingots, high-purity zinc ingots, Mg-Y intermediate alloy and Mg-Nd intermediate. The Mg-Zn-Y-Nd alloy disclosed by the invention has high corrosion resistance and high plasticity.

The invention provides a method for preparing a ceramic particle enhanced metal matrix composite coating in a laser cladding mode through an asynchronous powder feeding method. A lateral powder feeding nozzle is fixed to one coaxial powder feeding nozzle and assembled into an asynchronous powder feeding nozzle; the lateral powder feeding nozzle is used for feeding ceramic particle enhancing phases into the portion between the middle portion and the tail portion of the side, opposite to the laser scanning direction, of a molten pool; the coaxial powder feeding nozzles are used for feeding alloy powder or metal ceramic composite powder to the center of the molten pool; a laser device is used for conducting laser cladding, and then the ceramic particle enhanced metal matrix composite coating is obtained. According to the method, the coaxial powder feeding method and the lateral powder feeding method are combined, the ceramic particle enhancing phases are fed into the low-temperature region at the rear portion of the molten pool, so that the phenomena of nonuniformity of melting decomposition, clustering and distribution of the ceramic particle enhancing phases are reduced, and the ceramic particle enhancing phases are evenly distributed in the whole coating by keeping the original appearance to the maximum extent; accordingly, the ceramic particle enhancing phases are effectively retained and evenly distributed, and the performance of the composite coating can be substantially improved.

The invention discloses dual-beam laser selective melting and moulding equipment with an exchangeable powder cylinder. The equipment comprises two optical systems, a frame, a workbench plate, a powder feeding cylinder, a powder storage cylinder, a moulding cylinder, a powder returning cylinder, a moulding cavity, and two first driving mechanisms, which are used to respectively drive the moulding cylinder and powder feeding cylinder to move up and down. The workbench plate is fixed on the frame, the moulding cavity is fixed on the upper surface of the workbench plate, and the powder returning cylinder, the moulding cylinder, the powder feeding cylinder, and powder storage cylinder are fixed on the lower surface of the workbench plate from left to right in sequence. A scraper is arranged in the moulding cavity, and a second driving mechanism is arranged on the frame. A substrate is arranged in the powder feeding cylinder, a substrate is arranged in the moulding cylinder, the lower ends of the powder feeding cylinder and the moulding cylinder are both provided with a cylinder end cover, and the substrates are connected to a first piston system. A second piston system is arranged in the powder storage cylinder. The provided equipment has a high moulding efficiency and is capable of effectively reducing the deformation and cracking of members.

The invention provides a high strength alloy round aluminium rod and a production method thereof. Liquid aluminium with the content of more than 99.5% is added into a smelting furnace, the temperature is controlled to be 760-800 DEG C; silicon and magnesium and iron chelating agent are added, wherein the content of Si is controlled to be less than or equal to 0.6%, the content of Mg is controlled to be 0.3-0.9%, and the content of Fe is controlled to be less than or equal to 0.3%; aluminium melt is prepared, nitrogen is utilized to blow powder refining agent into the solution for refining, the usage amount of refining agent is 1.2kg/ton, and the pressure of nitrogen which is led in is 0.05-0.4MPa, thus obtaining aluminium melt with higher purity; and continuous casting and tandem rolling are carried out on aluminium melt subject to standing, before casting, Al-Ti-B rod is added in a chute at the speed of 150mm/min, so as to carry out online grain refinement treatment on the aluminium melt; and the rolled wire is subject to solid solution strengthening by virtue of an atomization quenching channel. Compared with common pure aluminium electrician round aluminium rod, the Al-Si-Mg alloy round aluminium rod of the invention has the advantages that: tensile strength is improved by 56.5%, the maximum can reach 64.6%; corresponding elongation is increased by 200%, the maximum can reach 228%; and resistivity is increased by only 28%.

The invention discloses a bloom continuous casting soft depressing technology in steel production and more particularly relates to a control method of the depressing quantity of the bloom continuous casting soft depressing. The invention aims at solving the technical problem of providing a control method which can determine the depressing quantity of the bloom continuous casting dynamic soft depressing according to different steel grades and obtaining the depressing quantity Delta S by adopting the following method (see the formula). The adoption of the control method of the depressing quantity can determine the depressing quantity of the dynamic soft depressing needed in different conditions of the continuous casting technology rapidly and effectively according to changes of the steel grades, and obviously reduce the central segregation of casting billets as well as reducing or even eliminating the appearance of central crack and central porosity.

The invention relates to an ultrasonic assisted laser electric arc composite welding method of an aluminum alloy. On the basis of carrying out a welding scheme by combining TIG electric arc welding and laser welding, ultrasonic vibration pressure is introduced into a welding seam, wherein a designed vibration head is in direct contact with the welding seam, so that ultrasonic resources can be more sufficiently utilized, and gas in the welding seam can be rapidly escaped; most of gas in the welding seam is removed so that welding seam gas pore defects are reduced or avoided; tissue crystal grains of the welding seam are remarkably refined by utilizing cavitation effect and acoustic streaming effect caused by the fact that ultrasonic waves are transmitted in liquid, and furthermore, tissue alloy elements of the welding seam are more uniform, segregation is reduced, the strength and corrosion resistance performance of the welding seam are improved, and the performance of a welding connector is improved; and welding residual stress is effectively eliminated or reduced and the strength and corrosion resistance performance of the connector are enhanced, so that the efficient welding of the aluminum alloy is realized.

The invention belongs to the technical field of alloy steel, and in particular, relates to a manufacturing method of Mn-Cr gear steel. The gear steel comprises the following components: 0.17-0.22% of C, 0.15-0.25% of Si, 1.10-1.40% of Mn, 1.00-1.30% of Cr, Mo not more than 0.08%, B not more than 0.0005%, Cu not more than 0.02%, Ni not more than 0.02%, 0.025-0.055% of Al, P not more than 0.015%, 0.020-0.035% of S, N not more than 130 ppm, and the balance of iron. The method improves the cleanness of molten steel through optimizing the refining process and the slag system control, performs the nitrogen adding treatment through a wire feeding procedure to effectively refine grains of the aluminum deoxidation gear steel, realizes precise control of hardenability alloy elements, solves the deoxidation and sulfur maintaining contradiction, and guarantees excellent pouring performance of the molten steel and excellent cutting performance of the gear steel.

The invention relates to an ultra-strong strength, high-toughness and anticorrosive aluminum alloy and a preparation method for the same. A trace amount of specially-reinforced rare earth elements Sm, Nd and Y are added on the basis of an Al-Zn-Mg-Cu-Zr alloy, an electromagnetic casting mode is adopted for improving the solid solubility of the alloy, homogenizing the structure and reducing segregation, and the proportion of main alloy elements is optimized to make a breakthrough in the strength of the alloy. The aluminum alloy has ultra-strong strength, higher plasticity and high anticorrosive performance; in addition, the high-abundance rare earth element such as Sm and Y serving as one of raw materials is excessively overstocked in the market, and is low in cost, so that not only can be the cost of the alloy remarkably lowered, but also the problem of application unbalance of the rare earth elements can be relieved; the strength of a material prepared from the alloy is stronger than 700MPa after the material is subjected to T77 treatment, and is remarkably stronger than that of a material prepared from a 7055 alloy, and the comprehensive performance of the material is remarkably higher than that of a material prepared from an Al-Zn-Cu-Mg aluminum alloy currently with the highest comprehensive performance.

The invention discloses an alloy ingot for an automotive hub and a production method thereof. The alloy ingot comprises the following components: 6.8-7.2% of Si, 0.28-033% of Mg, 0.10-0.15% of Ti, 0.015-0.030% of Sr, less than or equal to 0.10% of Fe, less than or equal to 0.05% of Mn, less than 0.01% of zinc, less than 0.01% of Cu, less than 0.003% of Ca, less than 0.002% of P, less than 0.02% of other single impurity content, less than 0.1% of total impurity content and the balance of aluminum. The production method of the alloy ingot for the automotive hub comprises the following steps of: adding 3303 industrial metallic silicon and electrolytic aluminum liquid for batching, heating at an appropriate temperature and melting, spreading a covering agent so as to reduce oxidation slagging, stirring so that the industrial metallic silicon rapidly melts, keeping uniform temperature, slagging off, keeping melt clean, spraying powder and refining by adopting high-purity N2 and a refined powder spraying agent, controlling the temperature of a smelting furnace to 740-750 DEG C, adding Al-Sr alloy to aluminium water, carrying out secondary degassing and slagging-off by adopting a powder spraying refinement method, filtering to remove slag, and casting the alloy ingot in line with requirements. The alloy ingot obtained by the method has the advantages of stable and uniform components, compact structure and clean surface; and the production method is the best production method for producing the A356.2 alloy ingot for the low-iron high-end automotive hub.

The invention discloses concrete with common strength and high elastic modulus and a preparation method thereof. The concrete with common strength and high elastic modulus, disclosed by the invention, is prepared from the following components in parts by mass: 100 parts of cement, 30-100 parts of an admixture, 1-10 parts of a nano material, 0.1-2 parts of a viscosity modifier, 200-600 parts of sand, 300-800 parts of crushed stones, 10-60 parts of fibers, 0.5-5 parts of a water reducing agent, 0.1-0.5 part of a powder dispersant and 50-90 parts of water. After the concrete with common strength and high elastic modulus, disclosed by the invention, is subjected to standard curing or natural curing for 28d, the strength grade of the concrete is C40-C50, and the elastic modulus can reach 50GPa or more; and the concrete has excellent working performance and endurance performance.

The invention discloses a production technology of a spring steel 60Si2Mn hot-rolled wire rod for an automotive suspension. The production technology comprises the steps of a hot metal pretreatment working procedure, a converter smelting working procedure, an LF refining working procedure, an RH vacuum treatment working procedure, a continuous casting working procedure, a cogging working procedure, an ingot blank polishing working procedure and a wire rod rolling working procedure. According to the production technology, the generation of AL2O3 inclusion is controlled from the source by meansof hot metal pretreatment desulfurization, silicon iron deoxygenation, silicon carbide diffusion deoxygenation and wollastonite and active lime slag formation; by the adoption of special carburant andspecial silicon iron, the content of nitrogen and the content of titanium in steel are controlled, argon protection in the whole process and the sufficient standing time are adopted, the situation that the inclusion fully and upwards floats is guaranteed, and D and Ds inclusion in the molten steel is controlled; by means of large ladle slag detection and special covering slag, the phenomenon thatthe molten steel is subjected to secondary pollution can be completely eradicated, and a good effect of thermal-insulating adsorption of the inclusion can be achieved; by means of the stir and soft press operation of a large rectangular blank crystallizer, the internal quality of an ingot blank is ensured; and in the rolling process, due to the optimization of the rolling speed and the control over the rolling temperature, the structure and the performance of a finished product are guaranteed.

The invention relates to high-toughness and hydrogen sulfide corrosion resistant round steel and a manufacturing method thereof. The round steel comprises, by mass, 0.25-0.40% of C, 0.20-0.45% of Si, 0.95-1.50% of Mn, 1.35-1.90% of Cr, less than or equal to 0.002% of S, less than or equal to 0.008% of P, 0.75-1.30% of Mo, 0.10-0.30% of Ni, 0.05-0.25% of V, 0.010-0.050% of Nb, 0.10-0.30% of Cu, less than or equal to 0.050% of Al, 0.0005-0.005% of Ca, and the balance Fe and unavoidable impurity elements. The hot-rolled round steel is produced through a process route of continuous casting-continuous rolling-annealing, the round steel is subjected to heat treatment directly, or a machined semi-finished drill tool is subjected to heat treatment. On the premise that related 130KSI and 135KSI synthesized mechanical properties are met correspondingly, according to an America NACE TM0177 standard hydrogen-sulfide-resistant stress corrosion test, a product is not broken for 720 hours under the condition that 70% of nominal yield stress is pre-loaded in a saturated H2S solution. The material is suitable for 130KSI-strength-grade and 135KSI-strength-grade drill tools under the mining environment of acidic oil and gas fields.