290 results about "Iron based alloy" patented technology

The invention belongs to the technical field of brake discs, and relates to a cast iron brake disc ceramic reinforced iron-based wear-resistant coating and a preparation method thereof.The cast iron brake disc ceramic reinforced iron-based wear-resistant coating comprises a brake disc base body, an iron-based transition coating and a composite wear-resistant coating, the composite wear-resistant coating is formed by mixing iron-based alloy powder, B4C ceramic particles and CeO2 rare earth powder; the preparation method comprises the following steps: 1, carrying out laser cladding on iron-based alloy powder on a brake disc substrate to prepare an iron-based transition coating; 2, carrying out ball milling and mixing according to a weight ratio to prepare composite wear-resistant mixed powder; 3, performing laser cladding on the iron-based transition coating with composite wear-resistant mixed powder; the B4C + CeO2 ceramic particles are mixed into the iron-based alloy powder, so that microcracks of the brake disc coating are reduced, the wear resistance and hardness are improved, dust pollution is reduced, the service life is prolonged, and the friction performance better meets the brake disc strengthening requirement.

The invention relates to steel for a long-service-life automobile water pump shaft connecting bearing and a production method of the steel, and belongs to the field of iron-based alloys, the steel comprises the following element components in percentage by weight: 0.80-0.90% of C, 0.65-0.85% of Si, 0.20-0.40% of Mn, less than or equal to 0.020% of P, less than or equal to 0.010% of S, 1.60-1.70% of Cr, 0.40-0.50% of Ni, 0.30-0.40% of Mo, less than or equal to 0.050% of Al, 0.0010-0.0020% of rare earth La, less than or equal to 0.0020% of Ti, less than or equal to 0.0010% of Ca, less than or equal to 0.0010% of O and the balance of Fe and inevitable impurities. The production process of the steel comprises the steps of electric furnace or converter primary smelting, external refining, VD or RH vacuum degassing, continuous casting, continuous rolling, normalizing, finishing and piece making and warehousing. The metallographic structure of the steel surface layer is a ferrite and pearlite structure, and the metallographic structure of the core part is cementite and pearlite. The rolling contact fatigue rated life of the steel material under the contact stress of 4.5 GPa is more than 5 * 107 times.

The invention belongs to the technical field of surface engineering, and particularly relates to a laser cladding iron-based corrosion-resistant and wear-resistant coating and a preparation method thereof. The invention relates to a laser cladding iron-based corrosion-resistant and wear-resistant coating which comprises the following iron-based alloy powder components in percentage by mass: 0.2-0.4% of C; 2.0 to 3.0% of B; the content of Cr is 12.0 to 16.0 percent; 0.5 to 1.0 percent of Ti; 0.5 to 1.5 percent of Si; 0.5 to 1.0 percent of Ni; 0.3 to 0.7% of Ce; s is less than 0.03%; p is less than 0.045%; and the balance of Fe. The coating has the beneficial effects that the coating takes the iron-based alloy powder as a raw material, and the iron-based alloy powder is uniformly cladded on the surface of the H13 steel by utilizing a laser directional energy deposition technology, so that a compact and uniform corrosion-wear-resistant cladding layer is formed, and the service life of the material under the working condition of erosion corrosion of molten aluminum is remarkably prolonged.

The invention discloses a polyolefin composite material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials, the polyolefin composite material comprises the following components in parts by weight: 18-32 parts of polyolefin resin, 19-31 parts of vinyl coupling agent modified metal powder, 19-31 parts of a nitrogen-phosphorus flame retardant, 4.5-11 parts of graphite and 0.9-5.2 parts of an interface improver; the vinyl coupling agent modified metal powder comprises a vinyl coupling agent and metal powder, and the metal powder comprises at least one of carbonyl iron powder, reduced iron powder, electrolytic iron powder and iron-based alloy powder. Under the combined action of the polyolefin resin, the vinyl coupling agent modified metal powder, the nitrogen-phosphorus flame retardant, the graphite and the interface improving agent, excellent electromagnetic shielding performance and flame retardant performance are obtained, and the polyolefin material is suitable for preparing electronic components, especially suitable for preparing electric control boxes, such as high-temperature-resistant materials, high-temperature-resistant materials, high-temperature-resistant materials, high-temperature-resistant materials, high-temperature-resistant materials, high-temperature-resistant materials, high-temperature-resistant materials and the like. The invention discloses a lithium battery pack and an electronic appliance protection shell.

The invention relates to the technical field of soft magnetic materials, in particular to an iron-based amorphous alloy strip, a preparation method of the iron-based amorphous alloy strip, an amorphous alloy iron core and a transformer. The iron-based amorphous alloy strip is composed of main elements of Fe, Si, B and C and inevitable impurities. Nicks distributed at intervals are formed in the surface of the iron-based amorphous alloy strip; the iron-based amorphous alloy strip has B80 / BS > = 0.96, where B80 / BS is the ratio of the magnetic flux density B80 generated when an external magnetic field of 80 A / m is applied to the iron-based amorphous alloy strip to the saturation magnetic flux density BS of the iron-based amorphous alloy strip. According to the amorphous iron-based alloy strip disclosed by the invention, the effective component proportion is combined with the strip for nicking, B80 can be effectively improved, the magnetic density design space of a transformer iron core is improved, the soft magnetic performance is improved, and meanwhile, a transformer has relatively low noise and no-load loss.

The invention relates to a high-performance non-quenched and tempered steel bar for a fan shaft and a manufacturing method of the high-performance non-quenched and tempered steel bar, and belongs to the field of iron-based alloys. The steel comprises the following chemical components in percentage by weight: 0.37 to 0.43 percent of C, 0.30 to 0.60 percent of Si, 1.20 to 1.70 percent of Mn, less than or equal to 0.025 percent of P, 0.030 to 0.070 percent of S, less than or equal to 0.50 percent of Cr, 0.10 to 0.30 percent of Ni, less than or equal to 0.30 percent of Mo, less than or equal to 0.30 percent of Cu, 0.010 to 0.030 percent of Al, 0.005 to 0.025 percent of Ti, 0.05 to 0.15 percent of V, 0.0100 to 0.0200 percent of N, less than or equal to 0.0002 percent of H, less than or equal to 0.0015 percent of O and the balance of Fe and inevitable impurity elements. The manufacturing process comprises the steps of converter / electric furnace smelting, LF furnace refining, RH / VD furnace vacuum degassing, continuous casting, casting blank reheating, cogging rolling, flame cleaning, intermediate blank finishing, intermediate blank heating, bar rolling, cooling and stress relief tempering. The total cross-section structure of the bar is a ferrite and pearlite structure. The bending degree per meter is smaller than or equal to 0.5 mm, the surface defect depth is smaller than or equal to 0.10 mm, and the internal quality meets the A-level requirement of the GB / T4162 standard.

The invention belongs to the technical field of insulation treatment of magnetic materials, and provides a preparation method of an oxidation-resistant high-resistivity soft magnetic composite material, which comprises the following steps: mixing an antioxidant metal organic framework (Cu-MOFs) with nano oxide and resin according to a certain proportion, and treating iron-based alloy powder. On one hand, the Cu-MOFs material is adsorbed on the surface of the magnetic powder to form a compact protective film to inhibit oxidation of a metal matrix, and on the other hand, the Cu-MOFs material has good compatibility with resin and is uniformly dispersed in a coating system, so that the permeation path of an oxidizing medium is effectively reduced, and the service life of the coating is prolonged. And rich functional groups of the Cu-MOFs material can change the surface characteristics of the nano oxide, the agglomeration effect of the nano oxide is reduced, the resistivity of the magnetic powder core is improved, and meanwhile the problem that the iron-based alloy magnetic powder core is oxidized and rusted in a special environment is effectively solved.

The invention provides a soft magnetic composite material and a preparation method thereof. The soft magnetic composite material is composed of amorphous nanocrystalline coated powder and iron-based alloy coated powder. Wherein the amorphous nanocrystalline coated powder comprises an amorphous nanocrystalline core and a first insulating coating layer group, and the iron-based alloy coated powder comprises an iron-based core and a second insulating coating layer group; the first insulating coating layer group and the second insulating coating layer group respectively and independently comprise a phosphate coating, a silicon oxide layer and a sodium silicate layer which are stacked, and the phosphate coating is arranged on the surface of the inner core. The surface of the alloy powder in the soft magnetic composite material is sequentially coated with the phosphate coating, the silicon oxide layer and the sodium silicate layer, mutual insulation between powder particles is achieved, eddy current generated between the particles under high frequency is effectively reduced, then eddy current loss is reduced, the overall performance of a power device is improved, and large-scale application and popularization are facilitated.

The invention discloses a preparation method for laser cladding of an iron-based alloy wear-resistant coating on the surface of an automobile brake disc, which comprises the following steps: (1) before cladding, putting iron-based alloy powder into a drying oven at 60 DEG C and drying for 120 minutes; (2) pretreating a matrix sample, removing rust and an oxide layer on the surface, cleaning the surface with absolute ethyl alcohol, and wiping to keep the surface dry; and (3) setting cladding process parameters, wherein the cladding process parameters comprise laser power, powder feeding amount, scanning speed, lap joint rate and scanning linear speed. And (4) a cladding experiment is started, and a cladding scanning path and mode are set, wherein the cladding scanning path and mode comprise a single-channel coating, a multi-channel lap joint coating and a whole-surface brake disc. And (5) after cladding is finished, waiting for natural cooling of the brake disc. The iron-based powder is used for preparing the coating on the surface of the automobile brake disc, technological parameters are optimized, the cladding procedure is simplified, the powder cost is low, the prepared coating is good in performance, and a single-layer coating scheme is provided for strengthening and repairing the brake disc.

The invention discloses a medium-entropy (Zr, Ta, W) C coating and a preparation method and application thereof. The medium-entropy (Zr, Ta, W) C gradient coating is prepared on the surface of the titanium alloy or the iron-based alloy through the double-layer glow plasma surface metallurgy technology, and gradient temperature annealing treatment is conducted. The preparation method has the specific advantages that (1) the prepared coating is of a continuous gradient structure, good interface metallurgical bonding is formed between the coating and a matrix, the bonding force of the coating is not lower than 50 N, and the coating is not prone to cracking and stripping in the service process due to the high bonding strength; and (2) the hardness of the medium-entropy (Zr, Ta, W) C coating prepared by the method is 25-30 GPa, the fracture toughness is 4.0-5.0 MPa * m < 1 / 2 >, and the coating system has balanced hardness and toughness, so that the coating is endowed with excellent wear resistance. The prepared coating has excellent wear resistance and antifriction performance, and has wide application prospects in the field of wear-resistant protective coatings.

The invention discloses an inductor based on low-voltage plastic package forming and a preparation method thereof, and relates to the technical field of metal soft magnetic composite material preparation. The method comprises the following steps: preparing iron-based alloy magnetic powder by adopting a gas atomization method; the prepared iron-based alloy magnetic powder is subjected to double-layer coating, and iron-based alloy coated powder particles are obtained; sintering to prepare a magnetic core, and winding the magnetic core; and putting the iron-based alloy coated powder particles into the wound magnetic core, and carrying out low-pressure plastic package molding to obtain the prepared inductor. According to the manufacturing method, the integrally-formed inductor is obtained through the low-voltage plastic packaging forming technology, the manufactured inductor has good comprehensive electromagnetic performance and high reliability, and the requirement for the miniaturization and modularization development direction of inductance devices can be met.

The invention belongs to the technical field of surface treatment, and particularly relates to a wide and thick plate rolling mill high-toughness stainless steel lining plate manufactured through laser cladding and a preparation method of the wide and thick plate rolling mill high-toughness stainless steel lining plate. The functional layer alloy powder of the lining plate comprises the following components in percentage by mass: 10%-15% of (Ti, W) C composite powder and the balance of iron-based alloy powder, wherein the iron-based alloy powder comprises the following components in percentage by mass: 0.1%-0.2% of C, 11%-13% of Cr, 0.2%-0.4% of Si, 0.2%-0.4% of Mn, 8%-10% of Ni, 1.0%-1.3% of Mo, 1.0%-1.5% of Al, 0.3%-0.5% of Nb, 0.3%-0.5% of Zr and the balance of iron. After a special coating material is adopted for cladding the plate surface, the impact resistance, the oxidation skin pricking resistance and the oxidation skin abrasive wear resistance of the plate surface under large rolling force can be improved, and the service life of the lining plate is prolonged; and a laser composite manufacturing method is adopted, so that the production cost of an enterprise can be reduced while the service life is ensured.

The invention relates to medium-carbon alloy steel for a large industrial bearing and a production method of the medium-carbon alloy steel, and belongs to the field of iron-based alloy. The round steel comprises the following chemical components: 0.44 to 0.50 percent of C, 0.15 to 0.35 percent of Si, 0.60 to 0.90 percent of Mn, 1.0 to 1.30 percent of Cr, 0.5 to 0.9 percent of Ni, 0.25 to 0.40 percent of Mo, 0.05 to 0.10 percent of V, less than or equal to 0.20 percent of Cu, less than or equal to 0.05 percent of Al, less than or equal to 0.0008 percent of Ca, less than or equal to 0.008 percent of S, less than or equal to 0.015 percent of P, less than or equal to 0.0020 percent of Ti, less than or equal to 0.0012 percent of O, less than or equal to 0.03 percent of As, less than or equal to 0.03 percent of Sn, less than or equal to 0.005 percent of Sb, less than or equal to 0.002 percent of Pb and the balance of Fe and inevitable impurities. The production process comprises the steps of molten iron pretreatment, converter smelting, LF refining, RH refining, CCM continuous casting round billet, annealing and finishing. Forging with the compression ratio of 6 or above is adopted, and the grain size is larger than or equal to 6 grades. And on the basis of meeting the quality requirement of the steel for the medium-carbon bearing, the production cost is lower, and the steel has very strong market competitiveness.

The invention discloses an impregnation liquid for an iron-based alloy magnetic powder core and an impregnation method based on the impregnation liquid. The impregnation liquid is prepared from the following components in percentage by mass: 5-15% of a metal organic compound, 5-20% of resin and 65-90% of an organic solvent. The impregnation method comprises the following steps that (1) iron-based alloy powder before insulation is put into impregnation liquid to be soaked, drying is conducted after soaking, and impregnated iron-based alloy powder is obtained; (2) carrying out insulation treatment on the iron-based alloy powder by using the nano silicon oxide dispersion liquid, and preparing an iron-based alloy magnetic powder core by using a powder metallurgy process after the insulation treatment, so as to obtain the iron-based alloy magnetic powder core; the obtained iron-based alloy magnetic powder core is cleaned and dried, and a to-be-impregnated iron-based alloy magnetic powder core is obtained; (3) completely immersing the iron-based alloy magnetic powder core into the impregnation liquid for soaking, and cleaning after soaking; and (4) heating and curing the cleaned iron-based alloy magnetic powder core, and naturally cooling to obtain the impregnated iron-based alloy magnetic powder core.

The invention relates to an automotive frame steel plate with tensile strength of 750MPa and a hot rolling control method thereof, and belongs to the technical field of iron-based alloys. The steel plate comprises the following chemical components in percentage by mass: 0.05-0.08% of C, 0.1-0.3% of Si, 1.7-2.0% of Mn, less than or equal to 0.025% of P, less than or equal to 0.0030% of S, 0.05-0.1% of Ti, 0.04-0.08% of Nb, less than or equal to 0.0060% of N, 0.02-0.06% of Al, 0.3-0.7% of Mo, less than or equal to 0.0050% of Ca and the balance of iron and inevitable impurities. During hot rolling, the continuous casting sheet billet is controlled to be heated to 1250-1350 DEG C and then rolled, the rough rolling finish rolling temperature is 1050-1000 DEG C, the finish rolling finish rolling temperature is 880-900 DEG C, the reduction rate is larger than or equal to 60%, laminar cooling after rolling adopts front-section cooling, the cooling speed is 40-50 DEG C / s, and a hot rolled steel coil is obtained through coiling when the coiling temperature is 600-650 DEG C. Through proper chemical component design and hot rolling process condition control, the high-strength hot-rolled acid-washed automobile beam steel plate with the yield strength of 700-800 MPa and the tensile strength of 770-850 MPa is obtained.

The invention belongs to the technical field of metallurgy, and particularly relates to an electrochemical dissolution method and device for promoting dissolution of high-temperature alloy, and the electrochemical dissolution device comprises an electrolytic bath, an anode plate, a cathode plate, a pore plate, a vibration basket, a vibrator, a stirrer, an oxygen generator and a heating and circulating pump; an electrochemical dissolving device is adopted, a titanium plate serves as an anode plate, a graphite plate or an iridium ruthenium plate serves as a cathode plate, an electrolyte is added into an electrolytic bath, the waste high-temperature alloy is placed into a vibration basket, an oxidizing agent is introduced into the electrolytic bath, electrolysis at 70 DEG C is conducted under the stirring and vibration conditions, filtering separation is conducted, and the waste high-temperature alloy is obtained. And electrolyte and anode mud are obtained. The method has the advantages of efficient metal dissolution, short recovery period and good recovery effect.

The invention discloses mixed soft magnetic powder, a method for preparing a soft magnetic powder core through the mixed soft magnetic powder, an obtained product and application. The mixed soft magnetic powder comprises powder A, powder B and powder C. The powder A and the powder B are independently at least one of iron-based amorphous alloy powder, iron-based nanocrystalline alloy powder and iron-based amorphous nanocrystalline alloy powder, the powder C is iron-based alloy powder, and the particle size of the powder A is larger than that of the powder C and larger than that of the powder B. The uniformly mixed soft magnetic powder is subjected to annealing treatment under the protection of hydrogen, then passivation insulation treatment and coating granulation treatment are performed, screening is performed, the screened powder is pressed, and the soft magnetic powder core with high density, high magnetic conductivity, low loss and good direct current bias capability can be obtained after annealing.

The invention relates to a steel plate API2Y-50 for a large-thickness high-standard ocean structure, and belongs to the technical field of iron-based alloys. The chemical components of the steel plate are based on API Spec 2Y standard requirements and comprise, by weight, 0.07%-0.12% of C, 0.10%-0.40% of Si, 1.00%-1.50% of Mn, smaller than or equal to 0.010% of P, smaller than or equal to 0.008% of S, 0.010%-0.030% of Nb, 0.020%-0.050% of Al, 0.010%-0.020% of Ti, 0.10%-0.25% of Cr, 0.20%-0.60% of Ni and the balance Fe and inevitable impurity elements. The carbon equivalent CEV is less than or equal to 0.43%, and the cold crack sensitivity coefficient Pcm is less than or equal to 0.24%. On the basis of an API Spec 2Y standard component system, the steel plate which is matched in high strength and toughness, easy to weld and excellent in lamellar tearing resistance and corrosion resistance is produced through the working procedures of KR, BOF smelting, LF, RH, slab continuous casting, slab slow cooling, heating, rolling, steel plate slow cooling, heat treatment and the like.

The invention relates to a thick hot-rolled spring wide steel plate, and belongs to the field of iron-based alloys. The steel comprises the following chemical components in percentage by mass: 0.47 to 0.55 percent of C, 0.17 to 0.37 percent of Si, 0.70 to 1.10 percent of Mn, 0.90 to 1.20 percent of Cr, 0.10 to 0.25 percent of V, less than or equal to 0.020 percent of P, less than or equal to 0.010 percent of S and the balance of Fe and inevitable impurities, and the structure is uniform ferrite and pearlite. The production thickness ranges from 41 mm to 55 mm, the width is larger than 2000 mm, and the length is not smaller than 6000 mm; the straightness is less than or equal to 3mm / m, and the thickness tolerance range is within 1mm. The hardness is smaller than 280 HBW, the inclusions A, B, C and D are all smaller than 1.5 grades, and the sum of the inclusions A, B, C and D is smaller than or equal to 3.0 grades and is larger than or equal to 2.0 grades. High purity, longitudinal and transverse performance uniformity and accurate thickness control of the large-size spring steel plate are achieved, the thickness machining amount of the steel plate is reduced by four times compared with that of a forging technology, the higher yield is achieved, and the production cost of large-size springs is greatly reduced.

The invention discloses an iron-based alloy composite wear-resistant material for preparing a roller sleeve flux-cored wire, and relates to the technical field of surfacing materials, the iron-based alloy composite wear-resistant material comprises the following raw materials by mass percentage: 52-58% of high carbon ferrochrome, 1-3% of chromium nitride, 1-2% of graphite, 8-11% of aluminum powder, 0.8-1.5% of nano yttrium oxide, 1-2% of modified carbon fiber, and the balance reduced iron powder; the modified carbon fibers are cerium oxide / reduced graphene oxide composite material modified carbon fibers. The nano yttrium oxide and the modified carbon fibers are added into the iron-based alloy composite wear-resistant material for preparing the roller sleeve flux-cored wire material, so that the hardness, toughness and wear resistance of the surfacing alloy material for the roller sleeve are effectively enhanced, and the wear loss of the surfacing alloy for the roller sleeve is remarkably reduced.

The application relates to a preparation process of a high-density powder metallurgy iron-based alloy, and relates to the technical field of metallurgical materials, in particular to a high-density powder metallurgy iron-based alloy preparation process. The preparation process comprises the following steps: taking copper (2%), nickel (2%), molybdenum (1%), graphite (0.3%) and the rest of iron according to the mass percentage, and making the above raw materials into 800-mesh powders; uniformly mixing the powders; pressing the mixed powders into blanks; sintering the blanks at 1100-1250 DEG C under a protective atmosphere or vacuum condition for 30-120 minutes; and obtaining the iron-based alloy product through shaping. The iron-based alloy material prepared by optimizing the powder granularity (800-1000 mesh), the pressing mode and the sintering is obviously superior to traditional powder metallurgy iron-based materials. The iron-based alloy product has the comprehensive advantages of high density, high strength, good size precision and stable performance, and has a wide industrial application prospect.

The invention discloses an iron-based titanium carbide additive as well as a preparation method and application thereof, and relates to the technical field of alloy materials. The iron-based titanium carbide additive is an iron-based alloy. The specific preparation method comprises the following steps: weighing a titanium source, a carbon source and an iron-based dispersing agent in proportion, and uniformly mixing to obtain mixed powder; rolling the mixed powder into a core-spun yarn or pressing the mixed powder into a cake-shaped material; weighing an iron-based raw material, and heating and smelting the iron-based raw material to form a raw material solution; adding the material rolled into the core-spun yarn or pressed into the cake shape into the raw material solution for reaction to generate an iron-based alloy melt; and the iron-based alloy melt is subjected to forming treatment, and the iron-based titanium carbide additive is obtained. According to the invention, through a synergistic process of'core-spun yarn / block cake + deep addition + in-situ reaction ', the prepared additive contains dispersed TiC particles, the particle size can reach the nanoscale, and the strength, toughness and wear resistance of the steel are remarkably improved.

The invention relates to the technical field of shield tunneling machines, and particularly discloses a shield hobbing cutter ring and a remanufacturing method thereof. According to the method, the iron-based alloy powder serves as a main body, the modified powder is added as an auxiliary, the remanufactured alloy powder is obtained, the alloy deposition layer is formed on the surface of the cutter ring body through the remanufactured alloy powder, and remanufacturing machining of the shield hob cutter ring is completed. Under the synergistic effect of the components of the modified powder, the alloy deposition layer can have good hardness and wear resistance, the defects of iron-based self-fluxing alloy are overcome, the defects of the remanufactured and repaired cutter ring in the tunneling process are reduced, and various extreme service conditions can be fully dealt with.

The invention relates to a wire rod for an 80-grade cord thread and a manufacturing method of the wire rod, and belongs to the field of iron-based alloys. The hot-rolled wire rod comprises the following chemical components in percentage by mass: 0.75%-0.85% of C, 0.10%-0.40% of Si, 0.30%-0.50% of Mn, less than or equal to 0.030% of P, less than or equal to 0.030% of S, 0.03%-0.15% of Cr, 0.03%-0.15% of Ni, 0.03%-0.15% of Cu, 0.01%-0.10% of Mo, less than or equal to 0.01% of N and the balance of Fe and inevitable impurities, Mn + Cr + Cu + Ni + Mo is more than 0.40% and less than 0.70%, Mn / 6 + (Cr + Mo) / 5 + (Cu + Ni) / 15 is more than 0.06% and less than 0.12%, Cr + Cu + Ni + Mo is more than 0.10% and less than 0.25% is more than 0.10% According to the wire rod, electric furnace smelting is achieved on the basis that the high-quality cord thread tensile strength and the low drawing wire breakage rate are guaranteed, the adding proportion of waste steel exceeds 70% of the total loading amount, and the production and manufacturing cost is reduced.

The invention relates to a pump body structure, a compressor and refrigeration equipment, and relates to the technical field of refrigeration equipment. The compressor comprises an air cylinder assembly, a crankshaft and a roller. The crankshaft is rotatably arranged in the air cylinder assembly in a penetrating mode. The roller is arranged on the crankshaft and located in the air cylinder assembly, the roller is driven by the crankshaft to roll along the cylinder wall of the air cylinder assembly, and the roller makes contact with the cylinder wall of the air cylinder assembly to jointly form a working cavity. The air cylinder assembly, the crankshaft and the roller are all made of light materials with the density smaller than that of iron-based alloy, and the absolute value of the difference of the linear expansion coefficients of any two of the air cylinder assembly, the crankshaft and the roller is not larger than a preset difference value, so that the preset gap among the air cylinder assembly, the crankshaft and the roller is kept stable. According to the technical scheme, the linear expansion coefficients of the air cylinder assembly, the crankshaft and the roller can be kept consistent while the weight of the pump body is reduced, and the stability of the preset gap is guaranteed.

The present invention forms part of the development of new iron-based alloys, particularly a steel with improved mechanical, thermal and physico-chemical (corrosion) properties. The invention relates more specifically to a steel material with a new microstructure, characterized by a triple hierarchical structuring in which appears a network of internal nanometric sub-cells capable of improving the properties and performance of steels.

To provide an Fe-based alloy for melt-solidification-shaping which can give a shaped object having small deformation during shaping, a high processing efficiency in an as-shaped state and a low content of expensive alloy elements when applied to melt-solidification-shaping, and a metal powder having a composition that is equivalent to that of the Fe-based alloy.SOLUTION: An Fe-based alloy for melt-solidification-shaping contains 0.05≤C≤0.25 mass%, 0.01≤Si≤2.0 mass%, 0.05≤Mn≤2.5 mass%, 2.5≤Ni≤9.0 mass%, 0.1≤Cr≤8.0 mass%, and 0.005≤N≤0.200 mass%, with the balance being Fe and inevitable impurities, satisfying 11.5<15C+Mn+0.5Cr+Ni<20. There is also provided a metal powder having an average composition that is equivalent to that of the Fe-based alloy.SELECTED DRAWING: Figure 3

This invention provides a fatigue-resistant high-strength spring steel and its preparation method. By synergistically designing the chemical composition of the iron-based alloy, the low-hydrogen clean molten steel intermediate, the hot rolling controlled cooling, and the quenching-partitioning heat treatment, the steel after stress relief treatment includes tempered martensite and 4-12 vol% retained austenite, and contains nano-precipitates. This results in a fatigue-resistant high-strength spring steel with a tensile strength of 2050-2250 MPa, an elongation after fracture of 8-12%, a reduction of area of ​​30-45%, and a rotational bending fatigue strength of 800-950 MPa. This invention solves the problem of balancing ultra-high strength and long-life fatigue resistance, and the difficulty in achieving both cold-rolling forming processing window and post-stress relief microstructure and dimensional stability. It is suitable for the preparation of high-load spring components.

The invention discloses a method for preparing a high-performance rare earth magnesium-silicon-iron alloy through cooperation of pulsed magnetic field treatment and multi-element microalloying, and belongs to the technical field of metallurgy. The method comprises the following steps: smelting ferrosilicon-based alloy liquid in a submerged arc furnace; the base liquid is thermally loaded into a medium-frequency induction furnace, trace elements such as Ba, Sr, Sb and Bi are added in a cored wire feeding mode, and electromagnetic stirring is conducted to achieve multi-element microalloying; the alloy liquid is heated and then subjected to pulsed magnetic field treatment, the parameters are as follows: the magnetic field intensity is 0.5-3.0 T, the pulse frequency is 5-30 Hz, and the treatment time is 5-20 minutes; then adding magnesium and nitrogen under pressure and stirring; and finally, casting and quickly cooling under the protection of nitrogen. The solidification structure is refined through the pulsed magnetic field, the yield of microelements is increased through core-spun yarn feeding, the magnesium oxide content is reduced through nitrogen protection in the whole process, segregation is restrained through rapid cooling, the magnesium oxide content in the prepared alloy is smaller than or equal to 6% of the magnesium content, the macrosegregation degree is smaller than or equal to 0.3, and the average grain size is smaller than or equal to 50 micrometers. The alloy prepared through the method is good in spheroidizing stability, uniform in structure, low in cost and suitable for production of high-end nodular iron castings.

An interconnector for a solid-oxide electrochemical cell stack of the embodiment includes: a metal base containing an iron-based alloy containing chromium; and a protective film provided on a surface of the metal base. The protective film includes a protective film body containing at least one selected from a spinel oxide and a perovskite oxide, and dispersed phases scattered in the protective film body and containing an oxide of at least one element selected from the group consisting of rare earth elements and zirconium.