277 results about "Embrittlement" patented technology

The invention discloses an austenitic stainless steel welding wire for a liquid hydrogen storage tank and a preparation method and application of the austenitic stainless steel welding wire, and belongs to the technical field of welding materials and preparation of the welding materials. The welding wire solves the problem that the low-temperature performance of a welding seam is poor when the current welding wire for the liquid hydrogen storage tank is used for welding. The welding wire comprises the following chemical components in percentage by mass: less than or equal to 0.02% of C, 0.4-1.5% of Si, 5.0-7.5% of Mn, less than or equal to 0.020% of S, less than or equal to 0.030% of P, 16.0-22.0% of Cr, 15.0-18.0% of Ni, 2.0-5.0% of Mo, 0.05-0.2% of N, less than or equal to 0.01% of O and the balance of Fe and inevitable impurities. According to the welding wire, deposited metal is low in low-temperature embrittlement tendency, high in low-temperature strength and excellent in low-temperature impact and fracture toughness. The welding wire is used for welding the austenitic stainless steel liquid hydrogen storage tank and is wide in application range, and the mechanical property of deposited metal is good.

The invention relates to the technical field of cables, in particular to a preparation method of a high-temperature-resistant low-temperature-resistant high-toughness cable material and a cable for an oil platform, the cable comprises a cable body, a bionic stranded conductor is arranged in the cable body, and a gradient insulating layer is fixedly connected to the surface of the bionic stranded conductor. The surface of the gradient insulation layer is fixedly connected with a three-layer co-extrusion sheath layer. According to the invention, the feasibility of a core innovation point (a bionic conductor and a gradient sheath) is proved through basic performance verification, the typical working conditions of an oil platform, such as low-temperature embrittlement and dynamic load, are covered through an extreme environment test, and the synergistic effect of key parameters (DCP dosage and vulcanization temperature) is determined through technological parameter optimization; the relation between quantitative repair efficiency and trigger conditions is verified through a self-repair mechanism, three-year equivalent aging is simulated through long-term reliability evaluation, the technical economy is proved, and meanwhile the core requirements of wide-temperature-range stability, mechanical fatigue resistance, chemical corrosion resistance and the like are met.

To suppress embrittlement of a powder line part material by production of zirconium carbide inside a powder line part, and occurrence of sudden troubles such as hole opening of the powder line part caused by the embrittlement.SOLUTION: A molten steel flow passage 5 includes an upstream flow part 50 provided with an inflow port 3, a downstream flow part 52 provided with a discharge hole 4, and a boundary part 51 in a boundary between the upstream flow part 50 and the downstream flow part 52, wherein a circle equivalent diameter DU of the upstream flow part 50 is set to be larger than a circle equivalent diameter DL of the downstream flow part 52, the boundary part 51 is provided at a position higher than the powder line part 6, and a lining layer 7, which is composed of a material different from a zirconia / graphite material and has thickness of 8 mm or more, is provided inside the power line part 6.SELECTED DRAWING: Figure 1

The invention discloses an anti-embrittlement flexible armored cable in an extremely cold environment. The anti-embrittlement flexible armored cable comprises a conductor, an insulating layer, a buffer isolation layer, a flexible armored layer and an outer sheath layer which are sequentially arranged from inside to outside. According to the armored cable, the structure of an existing cable is improved, the material formula of the insulating layer and the material formula of the outer sheath layer are optimized, the requirements for embrittlement resistance and high flexibility can be met, the protection performance of the armored cable can be enhanced, and aging tests show that the cable has good flexibility. The cable can meet the use requirement of long-term stable operation under the extremely cold severe condition with the temperature of-60 DEG C, has important practical significance and economic value, is reasonable in design, and is worthy of popularization and use.

The invention relates to the technical field of building materials, and discloses a self-repairing microcapsule-based composite waterproof material and a preparation method thereof, and the self-repairing microcapsule-based composite waterproof material comprises the following components by weight: 60-80 parts of modified organic silicon resin, 5-15 parts of nano clay (modified montmorillonite), 3-8 parts of a self-repairing microcapsule, 2-5 parts of a water-based cross-linking agent, and 0.5-2 parts of a dispersing aid. Stress generated by settlement and temperature change of a building structure can be effectively resisted, and cracks are reduced fundamentally; meanwhile, the material still keeps flexibility at the low temperature of-30 DEG C (without cracks when bent), and the technical bottleneck that a traditional material is prone to embrittlement in a cold region is broken through; more importantly, the 24-hour self-repairing rate is up to 92%, self-healing of cracks can be achieved without manual intervention, the service life of waterproof engineering is prolonged to more than two times that of a traditional material, the full-life-cycle maintenance cost is remarkably reduced, and a long-acting and reliable solution is provided for the field of building waterproofing.

The invention relates to the technical field of photovoltaic connector manufacturing, in particular to a temperature control forming process of a photovoltaic nylon connector mold and a composite runner, the mold is divided into a fixed mold area, a movable mold area, a mold cavity area, a mold core area and a pouring gate area, and each area is provided with an independent temperature control loop. According to different requirements of the mold filling state and the cooling stage of nylon materials, the temperature of each area of the mold is dynamically adjusted, the mold temperature is properly increased in the initial mold filling stage, a cavity is rapidly filled with melt, and along with mold filling, the mold temperature is gradually reduced, and melt cooling and crystallization are accelerated. According to the temperature control forming process of the photovoltaic nylon connector mold and the composite runner, the phase change energy storage material is embedded in the fixed mold area of the mold, and the heat absorption and release characteristics of the phase change energy storage material during phase change are used for assisting temperature control, so that the problem of embrittlement or insufficient strength caused by non-uniform crystallization of a product in a traditional process is solved; and the photovoltaic connector is ensured to have good mechanical property and weather resistance in long-term use.

The invention discloses a method for improving the welding performance of low-alloy high-strength wind power steel, which is characterized by comprising the steps of optimization of welding heat input, preheating before welding, welding process control and slow cooling after welding. By optimizing the welding heat input parameters, reasonably controlling the time (t8 / 5) for cooling to 500 DEG C from 800 DEG C, adjusting the structure transformation behavior of the welding heat affected zone and combining the process measures of preheating before welding, slow cooling after welding and the like, precise regulation and control of the microstructure of the welding heat affected zone are achieved, the hardening tendency and the embrittlement phenomenon of a coarse grain zone are effectively restrained, and the welding quality is improved. And therefore, the strength, toughness and crack resistance of a welding joint are remarkably improved, and the high requirements of offshore wind power structural parts for welding quality and service performance are met.

The utility model provides a dissimilar steel strip isolating layer submerged-arc welding structure which comprises a first base material and a second base material, the edges of the first base material and the second base material are subjected to the same beveling operation, specifically, the front side and the back side of each plate end are each provided with a beveled edge, the plate ends are assembled to form an X-shaped beveled edge, and a truncated edge is reserved in the middle of each beveled edge; and surfacing the edge of the first base material to form a first welding body with the same thickness, butting the edges of the first base material and the second base material, and welding to obtain a second welding body. According to the method, subsequent submerged-arc welding is converted into similar steel welding through the isolation layer structure, and the risk of cracking caused by interaction of high residual stress and brittle structures after dissimilar steel welding is eliminated; and meanwhile, the problems that a wide recarburization and decarburization layer is generated due to carbon diffusion migration in direct welding of dissimilar steel, and cracking is caused due to serious ferrite embrittlement of a decarburized wide ferrite belt under long-time heat treatment and high-temperature operation are solved.

The utility model relates to the technical field of turnover boxes, in particular to a low-temperature-resistant turnover box with a lateral outwards-protruding guide sliding structure, which comprises a turnover box main body and a sliding mechanism. According to the turnover box, through the arrangement of an anti-skid pad, an anti-skid block, a sliding groove, a first sliding block, a buckle and a clamping groove, firstly, the box cover is opened, the box cover is pushed to be closed after objects are put in, a first insertion buckle on one side of the lower portion of the box cover is inserted into an insertion buckle groove in one side of the top of the turnover box body to be fixed, and secondly, a protection mechanism in the turnover box body can buffer external impact force and vibration; the low-temperature-resistant coating prevents the main body from being embrittled and broken, and the insulation board maintains the low-temperature environment in the box and protects the quality safety of articles. And finally, the bottom non-slip mat increases friction force to ensure the stability of the turnover box, and the non-slip blocks on the two sides assist in guiding and prevent sideslip during transportation. When a plurality of turnover boxes are connected, the first sliding blocks are inserted into the sliding grooves, the buckles and the clamping grooves are clamped to guarantee firm connection, and the first sliding blocks can be pulled out by pressing down the buckles during separation.

The invention relates to the technical field of steel-plastic composite pipe machining, and discloses a steel-plastic composite pipe sealing forming device and method.The steel-plastic composite pipe sealing forming device comprises a base, a supporting mechanism, a sealing mechanism, a grinding mechanism and a fixing plate are arranged at the top of the base, and a rotating shaft is rotationally installed in the fixing plate; the sealing mechanism comprises an extrusion cylinder and a spiral auger, the spiral auger is rotatably mounted in the extrusion cylinder, one end of the extrusion cylinder is communicated with a square-opening extrusion nozzle, and a preheating mechanism and a flattening mechanism are arranged on one side of the extrusion cylinder. The device is reasonable in design, the temperature of a plastic layer and the contact pressure of the flattening roller are monitored in real time through a closed-loop control system integrating the temperature sensor, the pressure sensor and the semiconductor refrigeration ring, the temperature sensor dynamically adjusts the power of the semiconductor refrigeration ring, and the cooling airflow temperature is accurately controlled; embrittlement caused by too fast cooling of the plastic layer or deformation caused by insufficient cooling is prevented.

Disclosed in the present invention is a composite coating for steel. The composite coating comprises a first coating and a second coating which are sequentially arranged in the thickness direction of the coating, wherein the first coating is in direct contact with a steel substrate and comprises Mo and / or Cr, and the second coating is a zinc-based coating. Further disclosed in the present invention are a coating method for the composite coating, a steel plate comprising the coating, and a spot-welded joint comprising the steel plate. The present invention can greatly inhibit the phenomenon of liquid metal embrittlement caused by welding during a spot welding process, reduce cracks generated due to the phenomenon, and ensure the performance stability and functional stability of a steel plate, especially a galvanized high-strength steel plate.

This invention provides a crack-resistant, high-toughness composite packaging bag and its preparation method, relating to the field of composite packaging bag technology. The bag includes a bag body comprising an inner cold-resistant toughening layer, a middle elastic buffer layer, and an outer tough protective layer. The inner wall of the bag body has a material guide strip, and the bottom of the inner wall has longitudinal reinforcing ribs. The material guide strip has exhaust micropores. A flexible buffer pad is installed at the bottom of the bag body. Elastic buffer strips are provided on both sides of the bag body. Rounded transition corners are provided on both outer sides of the bottom of the bag body. In this invention, by using an inner cold-resistant toughening layer made of modified metallocene PE and POE toughening agents combined with a TPE material middle elastic buffer layer, the toughness of the bag body in low-temperature environments of -18℃ to -5℃ is significantly improved, preventing low-temperature embrittlement of the substrate. It can effectively withstand the instantaneous impact of high-speed filling of viscous materials, completely solving the problem of low-temperature embrittlement and cracking.

This invention relates to the field of alloy materials and discloses a method for preparing copper-chromium alloys by recycling copper-chromium alloy waste, comprising: 1) degreasing: immersing the copper-chromium alloy waste in an organic solvent to remove oil, cleaning, and drying; 2) embrittlement: placing the copper-chromium alloy waste in a hydrogen atmosphere, heating to above 500°C for at least 1 hour to embrittle, and then cooling; 3) cryogenic crushing: ball milling the copper-chromium alloy waste in liquid nitrogen medium to obtain copper-chromium alloy powder; 4) molding and pre-sintering: molding and pre-sintering the copper-chromium alloy powder to obtain a sintered blank; 5) densification: densifying and sintering the sintered blank to obtain a copper-chromium alloy. This invention sequentially processes copper-chromium alloy waste through degreasing, embrittlement, cryogenic crushing, molding and pre-sintering, and densification to obtain a copper-chromium alloy with high purity, high electrical conductivity, and high strength, achieving efficient recycling and reuse of copper-chromium alloy waste.

The invention belongs to the field of polymer composite materials, and discloses an antistatic composite material for a safety helmet and a preparation method of the antistatic composite material. Comprising the following components: 70 to 90 parts of a PC / ABS blending matrix, 12 to 20 parts of basalt fiber treated by a titanate coupling agent NDZ-311, 4 to 8 parts of a graphene quantum dot modified carbon nanotube-polyethylene glycol composite antistatic agent, 3 to 6 parts of polyaryletherketone micro powder, 0.2 to 0.6 part of an antioxidant 1010 and 0.4 to 1.0 part of calcium stearate. Wherein the mass ratio of PC to ABS in the PC / ABS blended matrix is (6: 4)-(7: 3); the invention aims to solve the problems that in the prior art, a single antistatic agent is difficult to consider the antistatic effect and the mechanical property, or materials are embrittled due to high addition amount, or the antistatic property fluctuates along with the environment and is easy to lose due to low addition amount; the interface bonding force between the conventional reinforced fiber and the PC / ABS matrix is weak, and the mechanical strength is limited to be improved; the long-term aging resistance of the material is poor, and the long-term use requirements of outdoor, chemical and other severe environments cannot be met.

A wrought nickel-molybdenum alloy containing 27.22 wt.% molybdenum, 4.73 wt.% iron, 0.47 wt.% chromium, 0.67 wt.% manganese, and 0.25 wt.% aluminum, and the balance nickel, as well as this alloy plus or minus the manufacturing variances typically encountered by each element during air melting, vacuum melting, and electro-slag remelting, have improved resistance to thermally-induced embrittlement over 100 hours at 1200⁰ F.

This invention discloses a method for improving the low-temperature impact toughness of high-strength heat-treated steel rails, comprising the following steps: composition control, smelting and refining, rare earth modification treatment, continuous casting / billing and heating homogenization, two-stage controlled rolling forming, online heat treatment with graded cooling and residual heat recovery, slow cooling on a cooling bed and straightening finishing. This invention determines the composition window based on the common constraint range of two sets of steel chemical composition standards for rails, and through the synergistic control of purification, effective rare earth modification, two-stage controlled rolling for grain refinement, and the online graded cooling and residual heat recovery heat treatment path, it reduces the sensitivity to low-temperature crack initiation, constrains the phase transformation path, and weakens the coupling between residual stress and microstructure embrittlement. Thus, while meeting the requirements for high strength, hardness, and wear resistance, it achieves qualified and stable low-temperature impact toughness.

To reduce, when producing a high-tensile-strength steel wire using a straight-type continuous wire-drawing machine, strain age hardening (embrittlement) caused by temperature rise of the steel wire, support high-speed wire drawing, and improve line set.SOLUTION: In wire drawing, at least in the drawing passes other than the final pass, a hole die or a roller die is used, and the cross-sectional shape of a workpiece material at a die exit is formed not as a circle but as an elliptical shape having a straight portion or as a rounded rectangular shape. By winding and taking up the workpiece material with the straight portion thereof in contact with a drawing capstan, rolling (twisting) of the workpiece material is restrained, and contact cooling by the drawing capstan is enhanced, thereby suppressing age hardening. The action of back tension also reduces processing heat generation. The restraint of twisting improves line set.SELECTED DRAWING: Figure 1

The invention discloses a low-polarity hot-melt pressure-sensitive adhesive, which is prepared from the following raw materials in percentage by weight: 50 to 70 percent of APAO polyolefin, 10 to 25 percent of alkane wax, 20 to 30 percent of petroleum resin and 0.1 to 1 percent of antioxidant. The APAO polyolefin with different melt viscosities and different molecular weights at 90 DEG C is adopted, so that the cohesion, flexibility and thermal stability of the colloid can be remarkably improved, and the problem of high-temperature flowing or low-temperature embrittlement generated by the APAO polyolefin with single performance is avoided. According to the invention, the balance between the low viscosity of 3000 + / -300cps at 150 DEG C and the high softening point of more than or equal to 120 DEG C is realized. And moreover, the quick opening time and the wide temperature range adaptability are considered, and the film covering performance of plastic films such as BOPP, PET and PE is improved.

The invention discloses a laser and electric arc hybrid welding method and a T-shaped structure, and the laser and electric arc hybrid welding method comprises the steps that a coating is arranged on one side of a first base material; abutting the end part of one end of the second base material against the coating layer; and welding the two sides of the second base material in the thickness direction to the coating. The coating is arranged on one side of the first base material before the first base material and the second base material are welded, and the coating can reduce the overall hardness of the joint of the first base material and the second base material, so that the risk of interface embrittlement of the joint of the first base material and the second base material in the welding process is reduced; and the ductility of the joint of the first base material and the second base material can be improved, so that the stress can be better dispersed when the joint is subjected to external force, and the risk of brittle fracture of the joint is reduced.

The invention belongs to the technical field of semiconductor processing auxiliary materials, and particularly relates to a PVC wafer protection film and a preparation method thereof. By compounding the polyester plasticizer and the powder modifier, a double insurance mechanism of'source replacement + adsorption anchoring 'is formed, so that an adhesive layer is effectively guaranteed to be completely separated from a base material when the PVC wafer protective film is stripped, and residual adhesive is further prevented from remaining on the surface of a wafer. According to the invention, the TPU elastomer and the rigid powder modifier are introduced to form a'soft-hard 'synergistic enhancement system, so that the prepared PVC wafer protection film shows puncture resistance far beyond that of a conventional formula when being punctured. By designing a multi-stage precise plasticizing control system, the plasticizing degree of PVC is synergistically regulated and controlled, the problems of molecular chain degradation, material embrittlement, puncture deformation and reduction of elongation at break caused by excessive plasticizing are effectively avoided, and meanwhile, the phenomenon that TPU and an inorganic powder modifier are non-uniformly dispersed is avoided.

The invention discloses a metal material irradiation embrittlement evaluation method based on surface thermal conductivity, which comprises the following steps: S1, irradiating a to-be-detected metal sample, establishing an irradiation damage amount-damage depth curve, and obtaining the maximum irradiation damage depth; s2, measuring the nano hardness of the non-irradiated metal sample and the irradiated metal samples with different irradiation damage amounts; s3, determining the test laser frequency, and measuring the surface thermal conductivity of the non-irradiated metal sample and the irradiated metal samples with different irradiation damage amounts; s4, establishing a nano hardness-surface thermal conductivity curve; s5, based on the test laser frequency, measuring the surface thermal conductivity of the irradiated to-be-measured metal sample, and determining the nano hardness of the irradiated to-be-measured metal sample; and S6, calculating the ductile-brittle transition temperature increment of the irradiated metal sample to be detected. The method effectively evaluates the irradiation embrittlement level of the metal material through nondestructive measurement of the surface thermal conductivity of the metal material, and has the advantages of nondestructive property, remote detection and real-time detection.

This invention discloses a waterproof and anti-corrosion waterstop for construction joints and its preparation method, relating to the field of engineering waterstop technology. This invention improves upon traditional waterstops by preventing them from gradually hardening, becoming brittle, or losing their elastic recovery ability during long-term use, thus ensuring that the material maintains high tear strength and elongation at break even after aging, overcoming the shortcomings of insufficient anti-aging synergy in traditional technologies.

The invention provides an environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable, relates to the technical field of cables, and solves the technical problems of material embrittlement, insufficient oxygen isolation, high temperature resistance and flexibility imbalance caused by high filling of a flame retardant in the prior art. The cable sequentially comprises a copper alloy conductor, a nano compound insulating layer, a ceramic oxygen barrier layer and a bio-based LSZH sheath layer from inside to outside, a material compound system realizes the balance of flame retardance and mechanical properties through nano inorganic flame retardance, organic synergistic flame retardance and base material modification, and the environmental protection property is improved by doping bio-based PLA; and through three-layer co-extrusion and sectional gradient irradiation crosslinking, the production efficiency and the product consistency are improved. The long-term working temperature of the cable is 150-180 DEG C, the flame retardant rating reaches class A, the smoke density is smaller than or equal to 100 Dm, the tensile strength is larger than or equal to 12 MPa, the fire-resistant time is larger than or equal to 180 min, and the material cost is reduced by 10-15%.

The invention discloses high-performance high-temperature steel for energy equipment suitable for an extreme environment and a preparation method of the high-temperature steel, and belongs to the technical field of high-temperature alloy materials. Waste steel circulation refining and residual element precise regulation and control are fully fused, waste steel efficient circulation utilization is achieved through a converter + LF / RH technology, CO2 emission and cost are reduced, and the energy consumption is reduced. And meanwhile, the residual element Sb in the waste steel is regulated to the beneficial interval of 0.002-0.010%, the high-temperature strength is improved through the grain refinement effect of the waste steel, grain boundary embrittlement is inhibited by combining the vacuum degassing and controlled rolling technology, collaborative innovation of waste steel resource recycling and high-temperature steel performance optimization is achieved, and the beneficial effects of green manufacturing and high performance are achieved.

The invention relates to the technical field of material crushing, and provides a material circulation low-temperature crusher system. The system mainly comprises a feeding bin, a crushing main machine, a cyclone material collector and a vibrating screen, wherein a discharging port is formed in the bottom end of the feeding bin and communicates with the feeding end of the first spiral conveyor, the discharging end of the first spiral conveyor is connected with the top end of the freezing pipe, the side wall of the freezing pipe communicates with the liquid nitrogen pipeline, the bottom end of the freezing pipe communicates with the feeding end of the smashing main machine, and the discharging end of the smashing main machine is connected with the feeding end of the draught fan; the discharging end of the fan is connected with the feeding end of the cyclone collector; the discharging end of the cyclone collector is communicated with the vibrating screen, the side wall of the vibrating screen is communicated with the feeding end of the spiral conveyor, and the discharging end of the spiral conveyor is communicated with the feeding bin. Liquid nitrogen is injected to conduct low-temperature embrittlement treatment on materials, so that the materials can be fully smashed, meanwhile, large-particle materials which are not fully smashed are screened out through the vibrating screen to enter the circulation again, and the material smashing effect is guaranteed.

The application discloses a kind of hierarchical PU insole production waste crushing regeneration recovery device, it is related to insole production field, including cylinder, vertical crushing mechanism and negative pressure backflow mechanism, the upper portion of the cylinder is equipped with top cover, the upper portion of the top cover is fixedly connected with low-temperature embrittlement treatment mechanism for the brittle and conveying of polyurethane plastic waste.The application, by three-stage gradient low-temperature embrittlement design, is matched with the turning and anti-sticking structure of the first auger conveyor and the second auger conveyor, weakens the elasticity of PU waste from the source, ensures that the material is brittle and uniform, completely eliminates the crushing rebound hidden danger, lays the foundation for efficient crushing of plastic waste, two-stage collaborative crushing and pushing mechanism reciprocating lifting design is combined, impact shearing and precision cooperation of rotary grinding are realized, matched with the guiding of material hopper to avoid material accumulation, compared with traditional one-way crushing, the crushing uniformity of plastic waste is greatly improved.

The invention belongs to the field of sealing materials, and discloses a high-pressure-resistant hydrogen embrittlement-resistant metal rubber composite sealing material and a preparation method thereof. The high-pressure-resistant and hydrogen-embrittlement-resistant metal rubber composite sealing material comprises a titanium alloy base material, a metal rubber layer and a metal rubber layer which are sequentially stacked from bottom to top, the titanium oxide layer is generated on the surface of the titanium alloy base material in situ; and the rubber layer is adhered to the surface of the titanium oxide layer through hot pressing treatment. The invention further discloses a preparation method of the high-pressure-resistant and hydrogen-embrittlement-resistant metal rubber composite sealing material, and the hydrogen-embrittlement-resistant metal rubber composite sealing material which can still keep stable deformation in a high-pressure environment is prepared by constructing the hydrogen-inhibiting oxidation layer and combining surface roughening, laser irradiation treatment and hot pressing treatment. After the high-pressure-resistant and hydrogen-embrittlement-resistant metal rubber sealing material is kept in a 100 MPa high-pressure hydrogen environment for 1000 hours, the tensile strength retention rate is larger than or equal to 88%, the percentage elongation retention rate after fracture is larger than or equal to 80%, and the deformation is smaller than or equal to 0.5%.

The invention belongs to the technical field of plastic pipe preparation, and particularly relates to a polypropylene hollow wall winding pipe and a preparation method thereof.The preparation method of the polypropylene hollow wall winding pipe comprises the following preparation steps of S1, raw material preparation, S2, base material extrusion, S3, winding forming, S4, welding reinforcement, S5, cooling shaping and S6, aftertreatment and detection. The ring stiffness and low-temperature impact resistance of the pipe can be synchronously improved through a composite modification system, the problem that the pipe is damaged due to low-temperature embrittlement after construction in winter in northern severe cold areas is solved, and deformation caused by insufficient ring stiffness after the pipe is deeply buried in soil is prevented; the pipe can stably adapt to complex scenes such as construction in a severe cold environment and pressure bearing of deeply-buried soil, is not limited by basic use requirements any more, and meanwhile, solves the processing problems of unstable melt flow and mold blockage during extrusion molding.

The application discloses a method for improving high-temperature water vapor oxidation resistance of FeCrAl alloy based on pre-oxidation, and the method comprises the following steps: performing surface pretreatment on FeCrAl alloy material; placing the pretreated FeCrAl alloy material in a high-temperature and high-pressure water environment to perform pre-uniform corrosion treatment, so as to form a double-layer oxide film; and placing the FeCrAl alloy material with the double-layer oxide film in a high-temperature water vapor environment to test the oxidation resistance thereof. The pre-uniform corrosion oxide film formed under the normal working condition of a nuclear reactor improves the oxidation resistance of the FeCrAl alloy under the accident high-temperature condition, especially enables the low-Cr-content FeCrAl alloy (Cr 10-12%) to have high-temperature oxidation resistance equivalent to or even better than that of the high-Cr-content alloy, and meanwhile, the irradiation embrittlement problem caused by the high-Cr-content is avoided, thereby providing technical support for development of a new generation of nuclear materials and safe operation of a nuclear power station.