35 results about "Carbon Dioxide / Helium" patented technology

Provided are: a carbon dioxide gas shielded arc welding wire capable of improving detachability of slag adhered to a bead surface after welding, while maintaining toughness of a weld metal; and a welding method using the welding wire. This welding wire is for use in carbon dioxide gas shielded arc welding performed with positive polarity, and has a chemical composition containing, in mass%, 0.200% or less of C, 0.05-2.50% of Si, 0.25-3.50% of Mn, 0.050% or less of P, 0.050% or less of S, 0.02-3.00% of Al, 0.0100% or less of O (oxygen), 0.0050% or less of Ca, and 0.010-0.100% of REM. In the REM, Nd is contained in an amount of 0.0015-0.0200%, and the remaining portion is Fe and unavoidable impurities. This carbon dioxide gas shielded arc welding method uses the welding wire and involves performing welding with a positive polarity by using, as a shield gas, a gas having a CO2 concentration of 60 vol% or more.

The invention provides a low-slag efficient smelting method and system based on immersed supersonic gas-solid injection, and relates to the field of metallurgy. The method comprises a raw material adding stage, a melting stage, an oxidation heating stage and a tapping stage. The low-slag efficient smelting system based on immersed supersonic speed gas-solid injection comprises an electric arc furnace, a powder injection tank, an immersed supersonic speed gas-solid oxygen lance and a control device, the electric arc furnace is used for smelting a target steel grade, the powder spraying tank is used for conveying a slagging material to the immersed supersonic gas-solid oxygen lance, and the immersed supersonic gas-solid oxygen lance is used for conveying the slagging material, methane, oxygen and shielding gas into a steel slag layer of the electric arc furnace; and the control system is used for controlling the immersed supersonic gas-solid oxygen lance. According to the low-slag efficient smelting method and system, the dephosphorization efficiency is improved by about 2.5-5%, the slag amount is reduced by 5-20 kg / t, the consumption of slag making materials is reduced by 5-10%, and the metal yield is improved by 0.5% or above.

The invention discloses a flue gas desulfurization and denitrification purification treatment system, the flue gas desulfurization and denitrification purification treatment system comprises an adsorption tower, a regeneration tower and a reaction tower, the adsorption tower is internally provided with an adsorbent, so that flue gas enters the adsorption tower, sulfur oxides and nitrogen oxides in the flue gas are adsorbed and removed by using the adsorbent, the regeneration tower is connected with the adsorption tower, and the reaction tower is connected with the adsorption tower. The reaction tower is connected with the regeneration tower, so that regenerated gas desorbed and regenerated by the regeneration tower enters the reaction tower for salt production, and part of tail gas generated by salt production of the reaction tower enters the regeneration tower so as to carry the regenerated gas to flow out of the regeneration tower. Part of salt manufacturing tail gas is used as shielding gas to replace nitrogen, so that the usage amount of the nitrogen in the regeneration tower is reduced, and the operation cost and the initial investment of the system are reduced. And moreover, the salt-making tail gas is rich in pollutants, so that the concentration of the pollutants in the regenerated gas can be effectively improved, and the salt-making reaction in the subsequent reaction tower is facilitated.

The utility model relates to a smoke discharging mechanism of a plasma cutting machine, which comprises the plasma cutting machine, the plasma cutting machine comprises a cutting gun, a gas collecting hood is arranged on the cutting gun, a protective gas guide sleeve is arranged on the cutting gun, and a gas conveying pipe through hole is arranged on the gas collecting hood. A first shielding gas conveying pipe is arranged on the gas conveying pipe passing hole and the shielding gas guide sleeve, the first shielding gas conveying pipe is communicated with the shielding gas guide sleeve, an air conditioning device is arranged on the gas collecting hood above the gas collecting hood, and the air conditioning device comprises a plurality of air conveying hole groups and an airflow adjusting sleeve which are arranged on the gas collecting hood; the air conveying hole group comprises a plurality of air conveying holes formed in the gas collecting hood, the gas collecting hood above the air conveying hole group is communicated with a tail gas discharge pipe, and an activated carbon adsorption tank and a sucking pump are arranged on the tail gas discharge pipe. Smoke generated in the cutting process can be extracted, and meanwhile air flow entering from a gap between the air collecting cover and a workpiece can be reduced; the utility model has the advantages of convenient use and wide market prospect.

The utility model belongs to the technical field of air separation waste nitrogen utilization, and particularly relates to a device for preparing high-purity nitrogen by recovering waste nitrogen on an upper tower of an air separation tower. According to the device, waste nitrogen at the top of the upper tower of the air separation tower is boosted by the booster device through the waste nitrogen rectifying tower and then fed into the waste nitrogen rectifying tower for rectification, high-purity nitrogen is obtained through rectification and purification in the waste nitrogen rectifying tower, and the boosted nitrogen of the high-purity nitrogen is fed into a 0.7 Mpa nitrogen pipe network to be used as shielding gas and replacement gas of the device; according to the utility model, nitrogen resources in the waste nitrogen are fully utilized, and oxygen and argon in the waste nitrogen are enriched at the bottom of the waste nitrogen rectifying tower and then are conveyed to the upper part of the air separation tower for rectification, so that the recycling of the oxygen and the argon in the waste nitrogen is also realized; the high-purity nitrogen is prepared by purifying the waste nitrogen at the top of the upper tower of the air separation tower, and the waste nitrogen does not need to be purified by a water washing tower and a molecular sieve, so that the production cost is low compared with nitrogen preparation by air.

The invention provides a method for growing a WS2 film based on PECVD, and belongs to the technical field of film growth. According to the method, the ionized sulfur source and the mixed shielding gas Ar are used, and the porous WO3 or WF6 is used as the precursor, so that the efficient growth of the WS2 film is realized. The method comprises the following steps: preparing a precursor; gas introduction: plasma excitation; growing a film; and post-processing. According to the method disclosed by the invention, the activity of reactants can be remarkably improved through plasma excitation, so that a faster growth rate can be realized at similar and even lower temperatures, and test results of Raman spectroscopy, XRD, AFM, electricity / optics and the like can prove that the WS2 film grown by adopting the method disclosed by the invention has good crystallinity and uniformity, high quality and high yield. The method is suitable for preparation of high-performance devices.

This invention discloses a method for extending the storage time of peaches, a composite plasma-activated water system, and a preservation system, belonging to the field of post-harvest preservation of fruits and vegetables. The method uses a quaternary gas mixture of argon, oxygen, carbon dioxide, and helium to prepare plasma-activated water through discharge. A specific ratio of tea polyphenols and chitosan is then added to obtain composite plasma-activated water. Combined with gentle pre-cooling, light-protected ultrasonic atomization spraying, and modified atmosphere buffering, this achieves a synergistic effect of antibacterial activity, water retention, antioxidant properties, and flavor preservation. This method can reduce the total bacterial count, rot rate, and weight loss rate of peaches during storage, maintain fruit firmness, enhance the activity of endogenous antioxidant enzymes, reduce malondialdehyde accumulation, and effectively retain soluble solids and titratable acids, among other flavor compounds. The process of this invention is green and mild, with no chemical residues, and can delay flesh softening and peel browning, thus extending the storage time and shelf life of peaches.

The invention discloses a preparation method of aluminum-based alloy powder using CO2 as shielding gas and aluminum-based alloy metal powder, relates to the field of metal powder preparation, and aims to solve the problems of high cost, low powder fluidity and low tap density in the prior art. And introducing carbon dioxide as shielding gas, melting, preserving heat, atomizing to prepare powder, cooling and screening. Carbon dioxide is used as shielding gas and can be obtained at low cost, liquid carbon dioxide is convenient to store and transport, the production cost can be effectively reduced, the molecular weight of carbon dioxide is higher than that of nitrogen, atomization kinetic energy higher than that of nitrogen can be obtained, and therefore the particle size of powder is refined, and generation of satellite powder and hollow powder is reduced; and the powder fluidity and the tap density are improved.

The invention relates to the technical field of foaming devices, in particular to a foaming device based on supercritical CO2 and a method thereof. According to the technical scheme, the device comprises a reaction kettle, a carbon dioxide conveying part, a negative pressure part, a shielding gas part, a circulating part, a temperature control part and a supporting plate system arranged in the kettle. The supporting plate system is provided with an accommodating chamber with an arc-shaped bottom surface, normal micropores are formed in the bottom, and a polymer sample can be suspended through airflow and is prevented from being in contact with a supporting surface, so that full-surface uniform foaming is realized. The method comprises the steps of loading, atmosphere replacement, supercritical environment establishment, dissolution saturation, rapid pressure relief foaming, unloading and the like. The method can effectively eliminate the shadow effect, improves the foaming uniformity and the product performance consistency, and is suitable for microcellular foaming preparation of various polymer materials.

The present invention provides a method for constructing a process database for typical characteristic structures of arc additive manufacturing, characterized by comprising the following steps: establishing the types, morphology curves, and characteristic dimensions of typical characteristic structures; inputting target characteristic structures, morphology curves, and characteristic dimensions; establishing the types, grades, and diameters of molten wires; establishing the grades and states corresponding to substrate materials; establishing the types of arc additive heat sources and their process modes; establishing the types of shielding gases; establishing a characteristic structure model optimization scheme; recommending an additive path for any characteristic structure model optimization scheme; establishing parameters related to actuators and external axes; and establishing process parameters related to arc additive manufacturing. The present invention achieves rapid matching of process parameters related to arc additive manufacturing, actively controls the forming quality of arc additive manufacturing while meeting the preset characteristic structure shape and size requirements, improves the surface quality, forming accuracy, and forming efficiency of arc additive manufacturing parts, and ensures the mechanical properties of the parts.

The invention discloses a plateau field welding method for high-strength bridge steel, which comprises the following steps: taking carbon dioxide as a protective gas, and adopting a solid welding wire with the following components in continuous backing weld, filling weld and cosmetic weld: C is more than 0.02% and less than 0.04%, Mn is more than 1.10% and less than 1.30%, Si is more than or equal to 0.2% and less than or equal to 0.40%, Cr is more than 0.50% and less than 0.60%, Ni is more than 0.40% and less than 0.50%, Cu is more than 0.30% and less than 0.40%, Mo is more than 0.05% and less than 0.20%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, and V is less than or equal to 0.04%. The balance is Fe and inevitable impurities; the welding parameters are set as follows: the welding voltage is larger than or equal to 26 V and smaller than or equal to 28 V, the welding current is larger than or equal to 260 A and smaller than or equal to 280 A, the welding speed is larger than or equal to 25 cm / min and smaller than 30 cm / min, the welding heat input is larger than or equal to 12 kJ / cm and smaller than or equal to 15 kJ / cm, and the shielding gas flow is larger than or equal to 15 L / min and smaller than or equal to 20 L / min. According to the method, the construction cost of the high-strength railway bridge is greatly reduced, and the performance of the welding seam obtained through welding is well matched with that of high-strength base metal.

The application discloses a MOCVD reaction device with an anti-oxidation and high-temperature-resistant heater, a gas path blocking cover is arranged at the lower part of a growth disc, the gas path blocking cover comprises an upper cover body, a lower cover body and a protection gas path, the upper cover body and the lower cover body jointly form a cavity with an annular air outlet at the upper part, one end of the protection gas path is communicated with the cavity, the other end of the protection gas path extends out of the reactor shell and is connected with a shielding gas source, the annular air outlet is located below the growth disc, shielding gas blown out of the annular air outlet forms a gas wall, the growth disc, the upper cover body and the gas wall form a sealed space capable of blocking the oxygen-containing reaction gas from entering, and the heater is located in the sealed space. The application can effectively prevent the heater from being corroded by the oxygen-containing reaction gas and prolong the service life of the equipment.

The invention relate to a method for producing a powder comprising UN2 and / or U2N3 and / or UN, the method comprising the steps of: a) heating a reaction zone in a vessel containing an NH3 atmosphere to a temperature in the range of 700 – 1200 °C to drive a reaction between UF6 and NH3, the pressure in the vessel being from 1 up to 45 atm; b) continuously injecting gaseous UF6 as a process gas into the reaction zone, optionally co-injecting with a shield gas around the UF6; c) continuously injecting gaseous NH3 as a process gas into the reaction zone, the amount of NH3 controlled to be in stochiometric excess for the reaction UF6 + 2 NH3 -> UN2 + 6 HF; d) reacting the process gases in the reaction zone, thereby forming the powder and gaseous HF; e) continuously, evacuating the powder and process gases including HF and excessive NH3 from the reaction zone; f) separating the powder from the process gases. The invention also relates to a reaction vessel having walls comprising a ceramic and / or a metallic material that preferably have low or zero catalytic activity for ammonia dissociation.

The invention relates to a smoke screen generation method and system and an infrared shielding type gas turbine type smoke generator. The method comprises the steps that a gas compressor is controlled to convey compressed air into a combustion chamber; a fuel oil supply device is controlled to convey a first preset amount of fuel oil into the combustion chamber, so that the fuel oil is incompletely combusted in the combustion chamber, and mixed flue gas with carbon black particles is formed; and a turbine is controlled to spray out the mixed smoke generated in the combustion chamber through an exhaust nozzle, and an infrared shielding smoke screen is formed. The technical problems that in the prior art, when an injection section is arranged behind a tail spray pipe, the smoke generator is large in size and heavy in weight can be solved.

The invention discloses a protective TIG (Tungsten Inert Gas) argon arc welding process for nano modified super aluminum alloy welding wire welding and application, relates to the technical field of nano metallurgical welding, and solves the problems that in the prior art, when TIG argon arc welding is adopted for 7-series and 2-series nano super aluminum alloy welding wire welding, high-purity argon is adopted for protection, the appearance of a welding seam is blackened, and the welding quality is poor. The technical problems that welding base metal has bright color, nano-particles in welding wires are slightly poor in dispersion, the mechanical property of an aluminum alloy welding test plate sample is reduced after T6 solid solution aging heat treatment, and the ductility is too low are solved. According to the protective TIG argon arc welding process for nano-modified super aluminum alloy welding wire welding, inert protective gas is argon-helium mixed gas, and the argon-helium mixed gas combination formula is argon-helium mixed gas of high-purity argon gas and high-purity helium gas. The volume ratio of Ar to He in the argon-helium mixed gas is 50%, or the volume ratio of Ar to He is 70%, or the volume ratio of Ar to He is 30%. The mechanical property of a welding seam can be greatly improved.

The invention discloses an energy-saving steel rolling annealing furnace shielding gas resource recovery and cyclic utilization system. A first purification subsystem receives shielding gas from an annealing furnace and removes dust and oil stains. And the heat recovery subsystem is used for exchanging heat for the protective gas subjected to dust and oil stain removal. And the second purification subsystem is used for pressurizing, deoxidizing and drying the shielding gas subjected to heat exchange and then inputting the shielding gas into the gas circulation subsystem. The gas circulation subsystem and the gas circulation subsystem are matched with each other, the nitrogen and hydrogen component proportion of the recycled protective gas is adjusted according to needs, and the recycled protective gas is fed into the annealing furnace after heat exchange is completed. The annealing furnace is optimized from two angles of nitrogen and hydrogen resource recovery and heat recovery, so that the problem of heat waste caused by direct emptying can be solved, the difficulty of incomplete recovery of resources caused by nitrogen and hydrogen separation can be overcome, and the problems that the nitrogen consumption of the furnace is increased and the load of an oxygen production system of an enterprise is not matched can be solved; energy conservation and carbon reduction of the annealing furnace unit are realized to the greatest extent.

The present disclosure discloses a process device using IPA, which comprises: a process tank for storing IPA. The process tank comprises a first inlet and a second inlet. The first inlet is connected to an IPA supply through a first pipeline. The second inlet is connected to a shielding gas supply through a second pipeline; in the process tank, the shielding gas provides an oxygen-free atmosphere, thereby prevents the IPA from being oxidized. The present disclosure further discloses a process method using IPA. The present disclosure can prevent IPA from being oxidized, thereby can prevent residual impurities formed by IPA oxidation.

The invention relates to the technical field of powder metallurgy, and discloses a method for preparing vanadium carbide powder through gas-based reduction, which comprises the following steps: uniformly paving a vanadium source at the bottom of a quartz boat and placing the quartz boat in a heating furnace; carbon reaction gas is introduced into the heating furnace, and after air in the furnace is discharged, the gas flow is adjusted to the gas flow required by reaction; the furnace temperature is increased to the reaction temperature in a segmented mode, and heat preservation is conducted continuously; heating is stopped after heat preservation is finished, reaction gas or inert gas is continuously introduced to serve as shielding gas to maintain oxygen partial pressure in the furnace, and the sample is cooled to 200 DEG C or below along with the furnace to obtain vanadium carbide powder. The high-purity vanadium carbide powder is prepared by selecting medium-temperature carbonaceous gas cracking and carburizing, the purity of the product prepared by the process route is high, the residual carbon content can be accurately controlled, the process flows of external carbon addition, ball pressing and the like in the traditional preparation method are avoided, the calcination temperature is effectively reduced, and the carburizing efficiency is improved.

The present application relates to a smoke generating method, system and infrared shielding gas turbine smoke generator. The method comprises: controlling a compressor to deliver compressed air into a combustion chamber; controlling a fuel supply device to deliver a first preset amount of fuel into the combustion chamber, so that the fuel is incompletely combusted in the combustion chamber to form mixed flue gas with carbon black particles; and controlling a turbine to eject the mixed flue gas generated in the combustion chamber through a tail nozzle to form an infrared shielding smoke screen. The present application can solve the technical problem of large volume and heavy weight of the conventional smoke generator when the ejector section is arranged behind the tail nozzle.

The invention relates to a wire arc additive manufacturing method (WAAM), the method comprising the successive formation of overlying layers from a filler material (1) to produce a shaped body through gas metal arc welding. The method includes the application of a shielding gas (9), the shielding gas comprising a mixed gas of an active gas and an inert gas, wherein the gas composition of the shielding gas (9) is such that an oxygen (O2) content of the shielding gas multiplied by a factor in the range from 2 to 3 plus a carbon dioxide (CO2) content of the shielding gas is in the range of 0.03 to 2 vol%.

This invention belongs to the field of tunnel construction safety monitoring technology, and provides a shield tunnel gas environment monitoring system and method based on dynamic decoupling and multi-source fusion. It acquires parameters of life-sustaining gases, toxic and harmful gases, flammable and explosive gases, and physical environment parameters within the tunnel. The acquired data is preprocessed; a pre-set cross-interference coefficient matrix is ​​corrected using temperature data; matrix decoupling is performed on the toxic and harmful gas parameter data to obtain the true gas concentration values; based on the correlation characteristics between humidity and particulate matter concentration, water mist interference is identified, and weighted compensation is applied to parameter data acquired by optical sensors; a tunnel safety index is calculated; and based on the tunnel safety index value and the gas concentration change rate, a pre-set decision tree control logic is matched to trigger corresponding levels of audible and visual alarms and equipment linkage. This invention can realize tunnel construction safety monitoring.

The utility model belongs to the technical field of annealing furnaces, and particularly relates to a shielding gas inlet system of an annealing furnace. The defects of unreasonable design and the like in the prior art are overcome. The shielding gas inlet system of the annealing furnace comprises a shell and further comprises a heat insulation layer, the heat insulation layer is arranged in the shell, and a heat insulation cavity is formed in the center of the heat insulation layer; the upper end and the lower end of the shielding gas cracking pipe are closed, and at least part of the shielding gas cracking pipe is inserted into the heat insulation cavity; the upper end of the shielding gas inlet pipe is fixed to the upper end of the shielding gas cracking pipe, the shielding gas inlet pipe is inserted into the shielding gas cracking pipe, and a gap is reserved between the lower end of the shielding gas inlet pipe and the lower end of the shielding gas cracking pipe; and the heating element is arranged in the heat insulation cavity. The method has the advantages that heat preservation of the shielding gas can be formed, so that the shielding gas is fully cracked, and the utilization rate of the shielding gas is increased.

The invention provides a method for preparing silicon carbide from coal gasification coarse slag and fine slag, and belongs to the technical field of coal slag resource recycling. Comprising the following steps: S1, carrying out acid pickling and ball-milling mixing pretreatment; s2, transferring the carbon-rich and silicon-source powder into a graphite boat carrier, introducing nitrogen as a shielding gas, balancing the pressure in the reactor to 0.015 Mp, and enabling the mixture in the graphite boat to react in a high-temperature air-isolated state; s3, calcining a reaction product in the graphite boat in a muffle furnace; and performing ultrasonic pickling to remove impurities, and then performing suction filtration to obtain high-crystallinity silicon carbide. According to the method, the coal gasification coarse slag is reasonably compounded into the fine slag, the traditional way of classified utilization of the coal gasification slag is broken, the energy loss is reduced by a short-time and efficient method, the high-crystallinity silicon carbide is prepared, and the method has positive significance in the solid waste resource recycling direction.

The invention discloses a coke heat intensity stability regulation and control technology and system for low-ash non-caking coal coking, and the technology comprises the following steps: carrying out moisture regulation and control and crushing on low-ash non-caking coal to obtain pretreated low-ash non-caking coal; mixing the modified starch with a functional additive compounded from high-caking-index prime coking coal / fat coal and modified starch-nano oxide (nano silicon dioxide / aluminum oxide) according to a preset mass ratio to form a coal blending system; a coal blending system is loaded into a coke oven carbonization chamber, after bulk density is controlled, segmented temperature control coking (low-temperature heating, medium-temperature heating, high-temperature constant temperature and pressure and atmosphere control in each stage) is executed, and parameters are dynamically optimized by an intelligent control system in the whole coking process based on a CRI prediction model; the coke is fed into a slow cooling device, inert gas is introduced, the type and flow of shielding gas are switched, the coke is cooled to the preset temperature or below according to the preset rate, and the coke with the heat intensity stability meeting the industrial requirement is obtained. The process can effectively improve the thermal strength stability of the coke, and meets the industrial application requirements.

The invention discloses a production method of an ultrathin T5CA hardness tin-plated substrate, which specifically comprises the following steps: taking a hot rolled steel coil with the thickness of 2.5-3.0 mm as an initial raw material, and carrying out acid pickling, cold rolling, continuous annealing, wet leveling and finishing procedures to prepare the ultrathin T5CA hardness tin-plated substrate, in the continuous annealing process, production is performed according to a T4CA process, the annealing temperature is 570-600 DEG C, and the speed is 260-300 m / min; a mixed gas of N and H is adopted as a protective gas, and the volume fraction of H in the protective gas is 5-10%; in the wet leveling process, the wet leveling reduction rate is controlled to be 5-10%, and leveling liquid with the concentration being 4-6% is used. According to the method disclosed by the invention, the tinned substrate with the thickness of 0.155-0.175 mm and the hardness of T5CA can be efficiently produced at low cost.

The invention belongs to the field of coal-based super-capacitor carbon preparation, and discloses coal-based super-capacitor carbon and a green activation method for producing the coal-based super-capacitor carbon, and the method comprises the following steps: uniformly mixing a coal-based carbonized material with soluble carbonate to obtain a mixture A; activating the mixture A in a protective atmosphere to obtain a pre-activated material; activating the pre-activated material in a mixed atmosphere of shielding gas and carbon dioxide to obtain a deep activated material; and washing the deeply activated material to remove soluble carbonate in the deeply activated material, and then filtering and drying to obtain the coal-based supercapacitor carbon. The method does not involve strong base, and has good environmental friendliness. And in the aspect of carbon material structure regulation and control, mesopores and micropores are respectively constructed by using a segmented activation process, so that a relatively good hierarchical pore channel structure is formed, and the energy storage performance of the supercapacitor is facilitated. Compared with random etching in a traditional mode, the mesoporous proportion is greatly improved.

The utility model relates to the technical field of thermosetting powder coating storage and maintenance, in particular to a thermosetting powder coating anti-oxidation device which comprises a storage tank, a nitrogen cylinder arranged on the left side of the outside of the storage tank, a control panel installed in the center of the top face of the outside of the storage tank, and an oxygen concentration sensor and a nitrogen concentration sensor arranged in the storage tank. A proximity switch is arranged on the right side in the storage tank, and a vacuum pump is installed in the back center of the outer surface of the storage tank. According to the antioxidation device for the thermosetting powder coating, discharge of oxygen and air in the container, injection of nitrogen shielding gas and whole-process monitoring of the gas sensor are achieved, the antioxidation effect of the container is greatly improved, the storage time of thermosetting powder is prolonged, the storage quality of the thermosetting powder is improved, and meanwhile the proximity switch is arranged inside to monitor the powder loading process; once the height position is close to the air outlet, the control panel is immediately combined to give an alarm, the situation that powder exceeds the limited height and covers the air outlet and the sensor is avoided, and stable operation of the device is ensured.

The invention discloses an efficient and compact device for extracting sulfur in different forms in soil and sediment, and relates to the technical field of analytical chemistry, the efficient and compact device comprises a device fixing unit, a protective gas supply unit, a heating reaction unit, a gas washing and collecting unit, a balancing mechanism and a control mechanism; wherein the protective gas supply unit, the heating reaction unit and the gas washing and collecting unit are respectively arranged in the fuming cupboard through the device fixing unit; the shielding gas supply unit, the heating reaction unit and the gas washing and collecting unit are hermetically connected through pipelines, and a balancing mechanism and a control mechanism are arranged in the shielding gas supply unit. Through cooperation of the control mechanism and the balancing mechanism, three modes of balanced gas supply, single-side centralized gas supply and unequal partitioned gas supply are realized, and the device is accurately adapted to diversified experiment scenes such as synchronous extraction of multiple groups of parallel samples, centralized reaction of part of branches and comparative analysis of different reaction conditions.

The invention discloses a protective gas mixing device for a laser powder bed fusion technology in the field of laser additive manufacturing, which comprises a bottom plate, four supporting columns, a supporting plate, a plurality of groups of gas tanks, a gas mixing bin, a gas conveying pipeline, a gas valve and a gas flow meter, the top ends of the four supporting columns are fixedly connected with the corresponding positions of the four corners of the supporting plate correspondingly, and the gas mixing bin is fixed to the top of the supporting plate through a top support. According to the invention, a Z-shaped gas flow path is formed by two layers of partition plates with staggered vent holes in the gas mixing bin, and precise premixing of protective gas is realized by matching with the double-gas component analyzer and the flow regulation and control module. According to the device, the problems of uneven mixing and large component error in the prior art can be solved, in Ti-6Al-4V alloy laser powder bed fusion printing, under the 5vol% argon-nitrogen mixed atmosphere, the yield strength of a part can exceed 1300MPa, the tensile strength of the part can exceed 1400MPa, the consistency of mechanical properties is remarkably improved, and the in-situ atmosphere strengthening method process requirements are met.

To provide a highly efficient arc-welding method capable of performing good single-sided welding even with a single electrode on a plate thickness.SOLUTION: This highly efficient arc-welding method uses a flux-included wire filling a copper outer coat with fluxes, and performs welding using a shield gas. In the flux-included wire, the fluxes contain a slug forming agent which is made of a metal oxide by 0.40-1.20% with respect to the total mass of the wire. As a fluoride or an oxide containing an alkali metal, one containing a total of 0.05-0.50%b by mass in alkali metal conversion value is used. As the shield gas, a mixed gas of a carbon dioxide gas and an argon gas, which contains the carbon dioxide gas by 40-70% and the argon gas by 60-30% at a volume ratio, is used. Welding current is within the range of 400-580A.SELECTED DRAWING: Figure 1