1515 results about "Hardness" patented technology

The invention discloses a control method applied to self-piercing riveting, and relates to the technical field of self-piercing riveting control. According to the method, riveting material data are collected in real time through a multi-source data fusion interface, the high-dynamic deformation process of a riveting head is captured, deformation rate and rebound value characteristic values are extracted, and a multi-dimensional process parameter set is constructed. And comprehensively analyzing the hardness, thickness and plastic dissipation characteristics of the material, and establishing an anti-deformation capability evaluation function. By introducing the fluctuation characteristics of the punching force, the nonlinear relation between the punching force and the elastic deformation of the riveting rod is analyzed, a hybrid compensation model is constructed, and a riveting dynamic coupling compensation vector is output. And generating a compensation weight matrix through an adaptive optimization algorithm, and dynamically adjusting the stamping force and the displacement of the riveting rod in combination with an anti-saturation control strategy. And dynamically adjusting a gain parameter through multi-scale filtering and a Lyapunov stability criterion, and triggering iterative updating of a compensation weight parameter during out-of-tolerance so as to optimize a control effect. Riveting precision and stability are improved, and the service life of equipment is prolonged.

The invention relates to the technical field of anti-fatigue of steel parts, and discloses an anti-fatigue system and method for a high-hardness steel part based on ultrasonic-shot blasting composite strengthening. The method comprises the steps that the macroscopic geometrical morphology, the microstructure and the dynamic stress-strain data of a target steel part are collected through a multi-mode sensing system, and a multi-physics field digital twinborn model is constructed through fusion; on the basis of fatigue damage feature distribution in the model, sorting by using an enhanced decision tree model, and triggering parameter configuration by using a priority over-critical value; synchronously calculating ultrasonic field regulation and control parameters and shot blasting trajectory planning parameters through an adaptive neural network algorithm; the parameters are injected into a digital twin model to simulate material response and energy transfer, data such as a microdefect closed state are output, and a parameter correction signal is generated through multi-dimensional consistency inspection. According to the method, precise control over composite strengthening is achieved, and the anti-fatigue performance of the high-hardness steel part is effectively improved.

The invention relates to the technical field of material metallurgy, and discloses high-wear-resistance hot-rolled round steel for titanium-containing steel balls and a preparation method thereof.The round steel comprises 0.60%-0.67% of C, 1.40%-1.60% of Si, 0.70%-0.90% of Mn, smaller than or equal to 0.020% of P, smaller than or equal to 0.015% of S, 0.70%-0.90% of Cr, 0.10%-0.15% of Ti, smaller than or equal to 0.30% of Ni, smaller than or equal to 0.40% of Cu, smaller than or equal to 0.05% of Al, smaller than or equal to 0.0020% of O, smaller than or equal to 0.0002% of H and smaller than or equal to 0.0035% of N; and the balance of Fe and inevitable impurities. Through the high-titanium-low-nitrogen microalloying design, the technical contradiction that the toughness is remarkably reduced when the strength and the hardness of traditional high-carbon steel ball steel are improved is solved, and excellent synergistic improvement of the strength, the hardness and the toughness is achieved.

The invention relates to the technical field of polymer foam materials, in particular to a preparation method of gradient cross-linked pearl wool microcellular foamation.According to a gradient cross-linked network constructed through a two-stage cross-linking technology, collaborative optimization of the performance of a surface layer and the performance of a core part of the material is achieved, a compact three-dimensional net-shaped structure is formed in a high-cross-linking-degree area of the surface layer, and the core part of the material is expanded; the surface hardness, wear resistance and tear resistance of the material are remarkably enhanced, external impact and friction damage are effectively resisted, the low-crosslinking-degree area of the core part retains the moderate movement capacity of a polymer chain, the material is endowed with excellent energy absorption characteristic and flexibility, and the material has good mechanical properties when bearing complex stress. Stress dispersion can be achieved through surface layer-core part synergistic deformation, fracture failure caused by local stress concentration is avoided, meanwhile, a gradient cross-linked network provides a controllable melt strength gradient field for supercritical fluid foaming, and therefore accurate control over the size and distribution of foam holes is achieved in the single-time foaming process.

The present invention provides a steel sheet having high strength and high ductility, and a method for manufacturing the same.　The steel sheet has a specific component composition and a structure mainly composed of ferrite. The amount of N present as AlN and the total amount of N satisfy relational expression (1), and the amount of Nb present as Nb precipitates and the total amount of Nb satisfy relational expression (2). The yield strength is 500 MPa or greater, the HR30T hardness is 66 or greater, and the total elongation is 7.0% or more. (1): (Amount of N present as AlN) / (total amount of N) ≤ 0.40 The total amount of N is the amount of all N included in the steel sheet. (2): 0.10 ≤ (amount of Nb present as Nb precipitates) / (total amount of Nb) ≤ 0.80 The total amount of Nb is the amount of all Nb included in the steel sheet.

The bainite plastic die steel comprises the following components in percentage by mass: 0.01-0.15% of C, 0.25-1.0% of Si, 0.5-2.0% of Mn, less than or equal to 0.045% of P, less than or equal to 0.015% of S, 2.0-5.0% of Cr, 1.01-2.0% of Ni, 0.0010-0.0050% of B, 0.004-0.008% of N and the balance of Fe and other inevitable impurities, and the following requirements are simultaneously met: the hardness index is more than or equal to 28 and less than or equal to 13.8 + 132.8 C + 2.34 Mn + 1.84 Cr-1.12 Ni and less than or equal to 38, and the bainite index is C 0.5 * Mn 1.4 * Cr 4 * Ni * N-1. 05 / 20 and less than or equal to 2000. According to the die steel, the tensile strength is larger than or equal to 800 MPa, the hardness is 28-38 HRC, the hardness difference value of the section of a steel plate with the thickness of 15-300 mm is smaller than or equal to 2 HRC, the straightness is smaller than or equal to 2 mm / m, and the flaw detection quality meets the E / e level requirement in the SP1921-84 standard. The method can be applied to manufacturing of plastic parts in the fields of automobiles, household appliances, medical treatment, electronics and the like.

The invention relates to the field of ferrous metallurgy and forge piece manufacturing, in particular to high-toughness, ultra-pure and large-quenching-depth 40CrNiMoRE rare earth special steel for a large ring piece and a preparation method of the high-toughness, ultra-pure and large-quenching-depth 40CrNiMoRE rare earth special steel. The invention relates to a high-temperature-resistant steel material, which comprises the following chemical components in percentage by weight: 0.3 to 0.5 percent of C, 0.1 to 0.5 percent of Si, 0.4 to 0.8 percent of Mn, 0.5 to 1.5 percent of Cr, 0.5 to 1.5 percent of Ni, 0.1 to 0.5 percent of Mo, 0.05 to 0.30 percent of V, 0.0005 to 0.0030 percent of B, 0.005 to 0.030 percent of RE and the balance of Fe and inevitable impurities. Through V, B and RE comprehensive microalloying, molten steel purification, inclusion modification and grain refinement, the hardenability is improved, and the surface quenching layer depth, hardness uniformity and impact toughness are ensured. And moreover, the high-toughness, ultra-pure and large-quenching-depth large ring piece is obtained through preparation technologies such as pure smelting, airtight protection pouring and uniform deformation, and the technical problems that an existing large ring piece is low in purity, poor in toughness, insufficient in hardenability, cracked in surface quenching and the like can be effectively solved.

The invention belongs to the technical field of tool wear measurement, and particularly relates to a machining center tool wear state early warning method based on multi-source data fusion, and the method comprises the steps: calculating a cutting power consumption characteristic through a main shaft load energy mapping model according to the original sampling current and the real-time feeding speed of a main shaft; sliding window sampling is carried out on the cutting power consumption characteristics, and the cutting state disorder degree is calculated; performing nonlinear coupling on the power consumption gradient item and the cutting state disorder degree to obtain a grinding loss stability coefficient; and establishing a dynamic statistical reference surface, and performing cutter state early warning according to the deviation degree of the grinding loss stability coefficient monitored in real time. Instantaneous interference caused by uneven material hardness is effectively recognized and eliminated, meanwhile, signal structure disorder at the initial stage of tool failure is captured, the technical problems that in die steel machining, due to material structure segregation and variable working conditions, the false alarm rate is high, and failure precursor capturing is difficult are solved, and the machining precision is improved. And the monitoring accuracy of the precision machining process is obviously improved.

The invention relates to the technical field of material mechanical property testing, and discloses a material indentation and scratch testing device and method under a composite energy field, and the device comprises a supporting experiment table, a vertical micro-motion platform, a horizontal micro-motion platform, a high-definition optical microscope, a force sensor, a displacement sensor and an additional energy field generation system. According to the method, a controllable additional energy field is synchronously applied while a mechanical indentation or scratch load is applied to a hard and brittle material sample, and load displacement data is collected in real time. In the data processing stage, the real hardness is calculated by adopting a corrected proportion sample resistance model, the elastic modulus is calculated based on the Oliver-Pharr theory, and the fracture toughness of the material is analyzed and calculated according to the size of the indentation tip crack. The problem that in-situ mechanical property characterization cannot be carried out in a composite energy field in a traditional test is solved, the hardness calculation precision is improved, the fracture toughness measurement function is expanded, and the experimental device and method are provided for research of a hard and brittle material composite machining mechanism.

A rolling method for reducing a carbide network rating of high-carbon chromium bearing steel, sequentially comprising: billet heating, descaling, rough rolling, intermediate rolling, controlled rolling, intermediate material segmentation, finish rolling, controlled cooling, and cooling on a cooling bed. By improving the rolling process and using a "segmentation before cooling" method to adjust the rolling procedure, the problems that the temperature is too low due to water quenching after rolling, the hardness of a rolled material is high, and normal operation of a shearing device cannot be guaranteed are solved, and the effect of reducing the carbide network rating is achieved, thereby avoiding the additional work procedures and costs caused by the non-compliant carbide network of the rolled material.

The invention provides a magnesium aluminate spinel-CMA multiphase material and a preparation method thereof, and belongs to the field of refractory materials. The refractory material comprises the following raw materials in percentage by mass: 80-87% of Al2O3, 6-19% of high-calcium magnesia and 1-7% of CaO. The mass percentage of the binding agent is 1-6% of the sum of the raw materials. The magnesium aluminate spinel-CMA multiphase material with excellent performance is synthesized from low-grade high-calcium magnesia, CMA large grains are tightly wrapped by magnesium aluminate spinel small grains, and a CMA phase and a magnesium aluminate spinel phase are uniformly distributed, so that the magnesium aluminate spinel-CMA multiphase material has the advantages of magnesium aluminate spinel and CMA materials, namely the magnesium aluminate spinel-CMA multiphase material has the characteristics of high hardness, wear resistance, thermal shock resistance, erosion resistance and the like.

The application discloses an easy-to-cut steel with excellent plasticity and drilling performance and a preparation method thereof, and the preparation method comprises the following steps: converter smelting, LF refining, continuous casting, hot rolling and air cooling line cooling; in the continuous casting step, the water quantity of a crystallizer is 130-140 m 3 / h, and the secondary cooling water quantity is 0.8-1.0 L / kg; in the air cooling line cooling step, the cooling speed is 1-1.5 DEG C / s from the spinning temperature to greater than 650 DEG C, and the cooling speed is 2-4 DEG C / s in the range of 650 DEG C-500 DEG C; under the condition of not adding easy-to-cut elements and increasing production cost, the plasticity and drilling performance of the easy-to-cut steel are significantly improved by controlling the manganese sulfide inclusion size, hardness and structure of the rolled material.

The invention belongs to the technical field of iron-based alloys, and particularly relates to a duplex stainless steel material and a preparation method and application thereof. According to the method, the chemical component content of the duplex stainless steel is precisely regulated and controlled, the cold-rolled steel is rapidly placed in water after being subjected to heat treatment at the temperature of 1050-1140 DEG C, so that the surface temperature is reduced to 120 DEG C or below, and the steel can be effectively promoted to form a stable and uniform duplex structure in the process. Performance tests show that the percentage elongation after fracture of the steel at room temperature reaches 35.3-39.2%, excellent plasticity and toughness are shown, it is ensured that the material is not prone to brittle fracture when stressed, and the deformation requirement under the complex working condition can be better met; the hardness value is 28.3-29.1 HRC, which indicates that the material has higher strength, can bear higher load and pressure, and meets the use requirements in a high-pressure environment; and the corrosion rate is only 0.343-0.771 [mu] m / 48 h in a 65% + / -0.2% nitric acid environment, the extremely high corrosion resistance is highlighted, and long-term stable service can be achieved in a highly corrosive medium.

The invention discloses a production method of high-toughness NM500 wear-resistant steel. The steel comprises the following chemical components in percentage by weight: 0.25%-0.26% of C, 0.15%-0.25% of Si, 0.88%-0.95% of Mn, less than or equal to 0.010% of P, less than or equal to 0.002% of S, 0.25%-0.30% of Cr, 0.015%-0.022% of Nb, 0.008%-0.016% of Ti, 0.020%-0.050% of Alt, 0.0014%-0.0020% of B, less than or equal to 0.00015% of H, less than or equal to 0.0040% of N, less than or equal to 0.0015% of O and the balance of Fe and inevitable impurities. CEV is not more than 0.48%, and Pcm is not more than 0.34%. The process comprises the steps of KR deS, converter smelting, LF refining, RH vacuum degassing, continuous casting, heating, rolling, slow cooling and heat treatment. According to the produced NM500 wear-resistant steel plate, the thickness covers 6-25 mm, the surface hardness ranges from 480 HB to 520 HB, the yield strength is larger than or equal to 1300 MPa, the tensile strength is larger than or equal to 1600 MPa, the elongation is larger than or equal to 14%, and the requirements that cold bending is conducted with the 6a diameter being 90 degrees, and the impact Akv at the temperature of-40 DEG C is larger than or equal to 45 J are met.

Provided in the present invention are a hardness evaluation method and system for a heat affected zone of a multi-layer and multi-pass welded joint of hull steel. The method comprises: establishing a finite element model of a welded joint, and acquiring welding thermal cycles at nodes in a heat affected zone of the finite element model; performing solving to obtain critical temperatures for microstructural transformations of a study object, and performing solving to obtain volume fractions of transformation products during the thermal cycles, and a volume fraction of an austenite-ferrite-pearlite mixture after all the thermal cycles; acquiring hardness values of a martensite and a bainite in each thermal cycle, and a hardness value of the austenite-ferrite-pearlite mixture after all the thermal cycles; and on the basis of the acquired hardness values of the martensite and the bainite in each thermal cycle, and the the acquired hardness value of the austenite-ferrite-pearlite mixture after all the thermal cycles, acquiring a comprehensive hardness value of the heat affected zone. The present invention can accurately reproduce heat conduction and a microstructure transformation process in a heat affected zone during multi-layer and multi-pass welding of full steel, thereby assisting engineers in evaluating a welding temperature field and the structure distribution of the heat affected zone.

The invention discloses a microalloyed high-toughness martensitic stainless steel cutter head as well as a preparation method and a preparation mold thereof. Stainless steel comprises the following components in percentage by weight: 0.3%-0.7% of C, 0.3%-1.0% of Si, 0.5%-1.5% of Mn, 16%-18.5% of Cr, 1%-2% of Ni, 0.3%-0.8% of Mo, 0.1%-0.35% of V, 0.1%-0.25% of Nb, less than or equal to 0.02% of S, less than or equal to 0.02% of P and the balance of Fe. Firstly, raw materials are smelted into molten iron; then adding a deoxidizing agent and precoated sand into the molten iron for molding, and performing sand mold casting and pouring to obtain a cutterhead blank; carrying out heat treatment on the cutter head blank; and finally, shot blasting and polishing are conducted on the cutterhead subjected to heat treatment. The martensitic stainless steel cutterhead has a metallographic structure which takes a martensitic structure as a main structure, takes austenite as an auxiliary structure and dispersedly distributes CrC, VC and NbC particles, the hardness of the martensitic stainless steel cutterhead is 40-45 HRC, the impact toughness of the martensitic stainless steel cutterhead reaches 92-95 J / cm < 2 >, the abrasion resistance of the cutterhead is longer, the service life of the cutterhead is longer, and the abrasion loss of the martensitic stainless steel cutterhead is reduced by 70% compared with a cutterhead without alloy elements.

The invention provides a self-adaptive control method and system for an extrusion screw of a plastic extruder, and relates to the technical field of plastic recovery and regeneration, and the method comprises the following steps: collecting operation data of the plastic extruder; calculating a change trend and an effective value according to the machine head melt pressure; a three-level partition model is constructed, a pressure deviation value is calculated based on the effective value and the target reference value, and a pressure control area is generated according to a comparison result of the pressure deviation value and a pressure threshold value; performing consistency judgment on the change trend and the pressure demand direction to generate an adjustment coefficient, and performing step length correction by combining a pressure control region and a motor load current to generate a rotating speed adjustment amount; the to-be-executed rotating speed of the screw is calculated in combination with the real-time rotating speed of the screw, acceleration limiting processing is carried out to generate the target rotating speed of the screw, and the target rotating speed is coded into a control instruction to be sent to the driving unit, so that the self-adaptive control effect of the extrusion screw can be achieved, and false pressure fluctuation caused by material hardness change is effectively prevented; the extrusion stability and the response speed are obviously improved.

The invention discloses a high-alloy steel nitriding-laser quenching composite surface strengthening method which comprises the following steps: sequentially polishing the surface of high-alloy steel by using 240-mesh waterproof abrasive paper and 2000-mesh waterproof abrasive paper, then sequentially putting the high-alloy steel into ethanol and acetone for ultrasonic cleaning, and nitriding the pretreated high-alloy steel to form a nitriding layer; and cooling to room temperature along with the furnace under the atmosphere of nitrogen or ammonia gas to obtain the high alloy steel containing the nitriding layer. And blackening treatment is conducted in the atmosphere of argon or nitrogen, then laser quenching treatment is conducted, and high alloy steel surface strengthening treatment is completed. According to the nitriding-laser quenching composite surface strengthening process, the problems that a high alloy steel nitriding layer is shallow (smaller than 0.2 mm), interface brittleness is achieved, and the retained austenite content is high (larger than 20%) are effectively solved, the total treatment time is shorter than or equal to 16 h, the surface hardness of a modified layer is larger than or equal to 600 HV0.1, the thickness of the modified layer is larger than or equal to 1.5 mm, and the nitriding-laser quenching composite surface strengthening process is suitable for preparing key components such as aviation gears and heavy-duty bearings.

The invention relates to a non-monotonic grain size gradient composite coating and a preparation method and application thereof.The non-monotonic grain size gradient composite coating comprises a fine grain layer, a coarse grain layer and a transition layer which are sequentially arranged on a substrate from bottom to top, grains in the fine grain layer, the coarse grain layer and the transition layer are columnar crystals, and the radial average size of the grains in the fine grain layer is 1t; the average radial size of crystal grains in the coarse crystal layer is 220-500 nm, and the average radial size of crystal grains in the transition layer is 50-200 nm. A fine-coarse-transition non-monotonic gradient crystal region structure is formed, a fine grain region of the composite coating provides high hardness, a coarse grain region of the composite coating improves toughness, a transition grain region simulates a mineralized gradient interface, stress dispersion is achieved, and the obtained composite coating shows more excellent comprehensive performance under complex working conditions and has high hardness, toughness and wear resistance.

The invention relates to a box type sand core type pouring system which comprises a sand box, a pouring system and a sand core box, and the pouring system comprises a first mold, a plurality of second molds, a cavity and a sprue; after sand is put into the sand core box to be solidified, the sand box is opened, and the first mold and the second mold are pulled out, so that channels, left on the sand box and the sand core box, of the first mold and the second mold form a transverse pouring gate and an inner pouring gate respectively; enabling the molten iron to sequentially pass through a straight pouring gate, an inner pouring gate and a transverse pouring gate to enter a cavity, and completing the molding of a casting; by optimizing the design of the pouring channel, uniform distribution of molten metal is achieved, the defects, such as air holes and shrinkage porosity, in a casting are reduced, and the overall quality of the casting is improved. By optimizing the design of the pouring channel, the hardness deviation of the plate surface is obviously reduced to be at least HB10, the sand inclusion and falling defects of the plate surface are eliminated, the use of consumables such as a ceramic tube, a rubber bottom and tube sticking glue is reduced, the production cost is greatly reduced, and the production efficiency is improved.

The invention discloses a production method of high-toughness NM450 wear-resistant steel. The steel comprises the following chemical components in percentage by weight: 0.19%-0.20% of C, 0.25%-0.45% of Si, 1.10%-1.20% of Mn, less than or equal to 0.010% of P, less than or equal to 0.002% of S, 0.65%-0.70% of Cr, 0.020%-0.025% of Nb, 0.014%-0.020% of Ti, 0.070%-0.090% of Alt, 0.0014%-0.0020% of B, less than or equal to 0.00015% of H, less than or equal to 0.0045% of N, less than or equal to 0.0015% of O and the balance of Fe and inevitable impurities. The process comprises the steps of converter smelting, LF refining, VD vacuum degassing, continuous casting, heating, rolling and heat treatment, the thickness of the produced NM450 wear-resistant steel plate ranges from 6 mm to 25 mm, the surface hardness ranges from 420 HBW to 480 HBW, the yield strength is larger than or equal to 1200 MPa, the tensile strength is larger than or equal to 1400 MPa, the elongation is larger than or equal to 14%, the requirement for 6a diameter 90-degree cold bending is met, the impact Akv at the temperature of-20 DEG C is larger than or equal to 60 J, the impact Akv at the temperature of-40 DEG C is larger than or equal to 40 J, the toughness performance is matched, the bending cold forming performance is excellent, and the welding performance is good.

The invention provides a multi-algorithm fusion-based water-based scratch-resistant plastic gloss oil formula optimization method, which comprises the following steps of: obtaining coating component data and environment variable data from a preset material database, and constructing an initial data set; performing crossover mutation operation on the initial formula parameters by adopting a genetic algorithm to generate a formula candidate set; according to the component proportion in the formula candidate set, obtaining a hardness index and a flexibility index through simulation, and performing grouping processing on the candidate set to obtain a grouped candidate set; for the grouped candidate set, adopting a support vector machine to carry out classified training on flexibility indexes of the high-hardness group, extracting performance deviation characteristics, and determining an adjustment vector; the formula parameters of the low-hardness group are corrected according to the adjustment vector, and the scratch resistance simulation data and the bending resistance simulation data are fused to obtain a corrected formula set; the coating performance under the environment variable change is sampled by adopting Monte Carlo simulation, performance fluctuation distribution is extracted, and an optimization formula and a process combination are determined.

The invention discloses a surface coating for prolonging the fatigue life of metal and a preparation method of the surface coating. According to the coating, face-centered cubic structure layers and hexagonal system structure layers are alternately stacked to form a superlattice structure, the total thickness ranges from 1.0 micrometer to 1.5 micrometers, and a base material is titanium alloy. The thickness of the face-centered cubic structure layer is 4-6 nm, the thickness of the hexagonal system structure layer is 1-3 nm, the Mohs hardness difference between the two layers is not larger than 2, and the average grain size is 1-2 nm. According to the coating, a stable high-toughness interface phase is obtained through a specific crystal structure and thickness regulation and control, and dislocation slippage and crack propagation are effectively prevented. A magnetron sputtering method is adopted for preparation, and the process comprises the steps of substrate surface pretreatment, bias cleaning and alternate deposition. The coating shows excellent anti-fatigue performance under the cyclic load condition, and the service life of the titanium alloy component can be remarkably prolonged.

The invention relates to the field of materials and processes for automobile parts, in particular to a homogenization evaluation method for hardenability of Ti-containing carburizing steel and application. According to different specifications and different looseness and segregation levels of the round steel, sampling regulation is carried out on the center part and the center part of the section of the Ti-containing carburizing steel round steel, and the hardenability and the hardenability bandwidth of the carburizing steel can be more truly reflected. When the hardness of the tail end hardenability sample is detected, two surfaces equidistant from the circle center of the section of the round steel are detected, a telecentric surface far away from the circle center of the section of the round steel and a proximal surface close to the circle center of the section of the round steel are detected, and compared with the current national standard, the detection result is more scientific and accurate. The method can be applied to almost all carburized steel bars with large component fluctuation, the uniformity is truly reflected, technicians can select raw materials with proper hardenability bandwidth to be applied to shaft gear parts with different size characteristics and using performance requirements, and the application prospect is very wide.

The invention discloses a high-performance Cu-Co-Si alloy plate and a preparation method thereof, and belongs to the technical field of copper alloy materials. The alloy plate comprises the following components in percentage by weight: 1.0-2.5% of Co, 0.2-1.0% of Si, 0.09-0.2% of Cr, 0.01-0.1% of Ni, less than or equal to 0.2% of Ti, less than or equal to 0.5% of Fe, less than or equal to 0.5% of Sn, less than or equal to 0.5% of Zn, less than or equal to 0.5% of P and the balance of Cu and inevitable trace impurities. The preparation method comprises the steps of smelting, semi-continuous casting, hot rolling, cold rolling, cleaning, stress relief annealing, solid solution, final cold rolling, aging and the like. According to the invention, alloy elements are reasonably matched and a preparation process is optimized, so that the alloy plate forms a nanoscale dispersed precipitated phase, dislocation motion is effectively hindered, grains are refined, and synergistic improvement of strength, conductivity and processability is realized. The thickness of the finished board is (0.02-0.15) + / -0.003 mm, the hardness is 180-220 HV, the electric conductivity is 62-66% IACS, the tensile strength is 620-680 MPa, 90-degree bending R / t is 0.5, and the finished board is free of surface defects and can be widely applied to the electronic and electrical field with high reliability and high performance.

The invention discloses a near-net forming friction welding method for a dissimilar metal stud based on a middle layer, which comprises the following steps of: pre-processing a similar T-shaped boss with a thread or a circular truncated cone-shaped boss without a thread section on the end surface of a workpiece with high hardness, and pre-processing a corresponding similar T-shaped groove or a circular truncated cone-shaped groove on the end surface of a workpiece with low hardness; and before welding, middle-layer alloy is placed at the upper end and the bottom of the T-like groove or the bottom of the circular-truncated-cone-shaped groove, and the welding steps comprise rotary pressing, rotary pressing and friction, sudden stop and upsetting. The intermediate layer alloy is used as a medium, direct contact friction of a welded workpiece is avoided, surface oxidation films of adjacent base metal are broken and gaps are filled through severe plastic deformation of the intermediate layer under rotary extrusion of the workpiece, and effective welding under the conditions of low upsetting friction pressure and no obvious deformation of the workpiece is achieved. And a dissimilar metal welding interface is prevented from being overheated to generate an overthick intermetallic compound, subsequent machining is omitted, near-net forming of a friction welding joint is achieved, and the production efficiency is improved.

There is provided a steel sheet that delivers an excellent appearance quality in its formed product. The steel sheet has a chemical composition including, in mass %, C: 0.030% to 0.145%, Si: 0% to 0.500% or less, Mn: 0.50% to 2.50%, P: 0% to 0.100%, S: 0% to 0.020%, Al: 0% to 1.000%, N: 0% to 0.0100%, and the like, wherein a metal micro-structure consists of 70 to 95% ferrite in volume fraction and 5 to 30% hard phases in volume fraction, and a value X1 obtained by dividing a standard deviation of Vickers hardnesses H1 / 4 at ¼ sheet-thickness positions by an average value of the Vickers hardnesses H1 / 4 is 0.025 or less, and a value X2 obtained by dividing a standard deviation of Vickers hardnesses H1 / 2 at a ½ sheet-thickness position by an average Value of the Vickers hardnesses H1 / 2 is 0.030 or less.

According to the NM450 wear-resistant steel suitable for the polar working condition and the production method thereof, low-cost component design is adopted, and the process steps comprise smelting, refining, continuous casting, heating, rolling and heat treatment; the steel-making process and harmful elements are strictly controlled to improve the purity of molten steel so as to improve the internal quality of the steel plate, and a strict rolling, quenching and low-temperature tempering heat treatment process is adopted. The NM450 wear-resistant steel plate which is high in toughness adaptability, high in wear resistance and excellent in cold forming performance comprehensive performance is developed, the thickness ranges from 6 mm to 30 mm, the surface hardness ranges from 450 HBW to 480 HBW, the core hardness ranges from 440 HBW to 465 HBW, and the core hardness reaches 95% or above of the surface hardness; the yield strength is not less than 1200 MPa, the tensile strength is not less than 1400 MPa, and the elongation is not less than 13%; the impact AKV at-50 DEG C is greater than or equal to 60J, and the impact AKV at-60 DEG C is greater than or equal to 40J; the bending angle is 90 degrees, the bending diameter D is 6a, and the cold bending result is intact.

The invention provides a method for measuring the position of a welding seam by using a Leeb hardness tester. Comprising the following steps that firstly, a theoretical position line of the center of a welding bead is drawn according to a reference positioning datum; secondly, two datum lines parallel to the theoretical position line of the center of the welding bead are drawn out; thirdly, weld bead excess weld metal or protrusions at the measuring positions on the two sides of the center line are polished and removed; step 4, a measurement position line is drawn between the two datum lines, the measurement position line is perpendicular to the two datum lines, and a measurement point is drawn on the measurement position line every 3mm; step 5, measuring the hardness of each measuring point by using a Leeb hardness tester, wherein each measuring point is measured for more than three times; analyzing an average value of measurement data of each measurement point, and drawing a hardness-position curve graph according to a position corresponding relation; obtaining the position and boundary dimension information of the welding seam according to the measurement position point by comparing the hardness change area; and more accurate position and boundary dimension information of the weld joint is obtained in a measurement point encryption mode.

The invention discloses a method for rapidly optimizing components and heat treatment of super martensitic stainless steel, and relates to the technical field of material research methods.The method comprises the steps that firstly, a wide component FCC phase region of a stainless steel system is determined according to a phase diagram calculation result, end component components are determined, and then two end components are obtained through smelting and linear cutting in sequence; and fixing the two end components together, annealing and carrying out subzero treatment to obtain a super martensitic stainless steel diffusion couple, and finally carrying out component gradient analysis and hardness and Young modulus test on the diffusion couple to obtain the corresponding relationship among the components, hardness and Young modulus of the stainless steel under different heat treatments. Therefore, the composition of the high-hardness super martensite and corresponding heat treatment parameters are determined. A large amount of approximately continuous phase composition-component-heat treatment-hardness-Young modulus corresponding experimental data information can be obtained in a short time, and the high-performance martensitic stainless steel and heat treatment parameters thereof can be quickly optimized.