43 results about "Brinelling" patented technology

The invention belongs to the technical field of aluminum alloy materials and preparation thereof, and relates to a high-strength and high-toughness die-casting aluminum alloy and a preparation technology and application thereof.The aluminum alloy comprises Si, Mg, Cu, Mn, Zn, Fe, Cr, Ti, Zr, Sr, Sb, B, La, Ce, Be, P, smaller than or equal to 0.05% of other single elements, smaller than or equal to 0.15% of other impurity elements in total and the balance Al element, the content of Sr and the content of Sb cannot be larger than or equal to 0.005% at the same time, and the balance Al element. According to a singly-cast sample prepared from the high-toughness die-casting aluminum alloy, the tensile strength at the room temperature is 380-450 MPa, the yield strength is 250-350 MPa, the ductility is 3-8%, the brinell hardness is larger than or equal to 105 HB, the electric conductivity is larger than or equal to 19 MS / m, and the heat conductivity is larger than or equal to 140 W / m.K; and at the temperature of 200 DEG C, the tensile strength ranges from 280 MPa to 350 MPa, the yield strength ranges from 220 MPa to 290 MPa, and the ductility ranges from 5% to 10%.

The Brinell hardness tester comprises a hardness tester body, a winch, a supporting unit, a pressing unit and a detection pressing head are arranged on one side of the hardness tester body, the winch is rotatably connected with the hardness tester body, the supporting unit is suitable for being supported between the hardness tester body and a to-be-tested pipeline, and the pressing unit is suitable for pressing the detection pressing head on the to-be-tested pipeline; one end of the fixing assembly in the length direction is detachably connected with the durometer main body, the other end of the fixing assembly is wound on the winch, and at least part of the fixing assembly and the detection pressure head are arranged on the same side of the durometer main body; the fixing assembly comprises a bandage and a first fixing piece, the first fixing piece comprises a plurality of fixing plates, the fixing plates are sequentially connected, every two adjacent fixing plates are rotationally connected, and the bandage is sequentially connected with the fixing plates. According to the Brinell hardness tester disclosed by the invention, the space between the fixing assembly and the hardness tester main body is adjusted through rotation of the winch, so that the Brinell hardness tester can adapt to measurement requirements of pipelines of more models.

A tempering-free wear-resistant hot rolled strip, includes components in percentage by weight: 0.08-0.22% of C, 0.1-0.55% of Si, 0.8-1.5% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, 0.01-0.055% of Als, 0.005-0.019% of Ti, and less than or equal to 0.007% of N. A method for producing the same includes: desulfurizing molten iron, smelting desulfurized molten iron, and casting into a blank; heating the casting blank; performing rough rolling; performing finish rolling; performing rapid cooling; performing coiling; and performing conventional temper rolling. According to the present disclosure, on the premise that the tensile strength of a steel plate is greater than or equal to 1100 MPa and the elongation is greater than or equal to 12%, the steel plate has a surface Brinell hardness of 330-390 and a core hardness that is 95% or above of the surface hardness.

The application discloses a kind of gear steel 20CrMnTiH round steel heat treatment process, belong to metal material heat treatment technical field.The process is aimed at gear steel 20CrMnTiH round steel, through the multi-dimensional combination optimization of heating holding parameter, cooling mode and tempering process, realize the hardness and organization uniformity precision control of round steel heart, 1 / 2R place and edge, solve the technical problems that the hardness distribution of the specification round steel is uneven under traditional heat treatment process, organization defect is easy to produce, process adaptability is poor.The application process operation controllability is strong, parameter range adaptability is wide, the Brinell hardness difference of each part of 20CrMnTiH round steel after processing is small, metallographic structure is uniform and dense, without wassermann structure and other defects, comprehensive mechanical properties are excellent, suitable for large-scale industrial production, with higher practical value and popularization prospect.

The invention discloses a production method of a low-alloy normalizing container plate. After normalizing, a steel plate with the thickness of mm is subjected to accelerated cooling through a quenching machine, wherein the density I of gaps 1 and 2 is 8-25, the water ratio is 1.55, 1.55, 1.7 and 1.8, the water feeding amount m < 3 > / h is 200, 200, 140 and 140, and the roll gap is the thickness of the plate; 26-36 high densities I and II are used, the low pressure is 1, the water ratio is 1.7, 1.8 and 2.0, the water feeding amount is 140, and the roll gap is the plate thickness; when the plate thickness is 37-48, the low pressure is 2-9, the water ratio is 2.15, the water feeding amount is 140, and the roll gap is equal to the sum of the plate thickness and the plate thickness; when the plate thickness is 49-64, the low pressure is 2-9, the water ratio is 2.0, the water feeding amount is 135, and the roll gap is the sum of the plate thickness and the plate thickness; 65-89, the low pressure is 1-9, the water ratio is 2.0, the water feeding amount is 120, and the roll gap is the thickness of the plate plus 5. Reasonable matching of the surface Brinell hardness in the delivery state and the pulling force at the 1 / 2 position in the die welding state is achieved, and the flatness of the plate shape is guaranteed.

The invention discloses corrosion-resistant high-strength saw blade steel and a manufacturing method thereof, and belongs to the field of metallurgy and metal materials. The steel for the saw blade comprises the following components in percentage by mass: 0.63 to 0.70 percent of C, 0.46 to 0.62 percent of S i, 0.79 to 0.98 percent of Mn, less than or equal to 0.033 percent of P, less than or equal to 0.014 percent of S, 0.15 to 0.35 percent of Cr, 0.44 to 0.68 percent of Cu, 0.23 to 0.35 percent of N i and the balance of Fe and impurities. The manufacturing method comprises the steps of molten iron pretreatment, converter smelting, LF refining, VD vacuum treatment, continuous casting, casting blank slow cooling, steel billet heating, rolling, heat treatment, straightening, inspection and the like. According to the corrosion-resistant high-strength steel for the saw blade, a uniform pearlite structure is obtained, the Brinell hardness of a product is larger than 340 HBW, the tensile strength is larger than 1180 MPa, and the corrosion resistance is improved by 44% or above compared with that of conventional steel for the saw blade.

The application relates to a high-strength high-thermal-conductivity aluminum alloy and a preparation method thereof. The high-strength high-thermal-conductivity aluminum alloy comprises the following components: Si 9.0-11.0 wt%, Fe 0.5 wt%, Mg 0.5 wt%, Sc 0.4 wt%, Zn 0.005-0.01 wt%, Mn 0.01 wt%, B 0.02-0.04 wt%, Cu 0.02-0.05 wt%, inevitable impurities and the balance of aluminum. The high-strength high-thermal-conductivity aluminum alloy has the properties of high thermal conductivity and high strength, the tensile strength is greater than or equal to 270 MPa, the yield strength is greater than or equal to 173 MPa, the elongation is greater than or equal to 5.3%, the thermal conductivity is greater than or equal to 183 W / (m*K), the forming flowability is greater than or equal to 1330 mm, and the Brinell hardness is greater than or equal to 119 HB. The high-strength high-thermal-conductivity aluminum alloy can be recycled multiple times, and the high-strength high-thermal-conductivity aluminum alloy can still maintain high thermal conductivity, mechanical properties and flow forming properties after multiple recycling. The aluminum alloy has high-strength high-thermal-conductivity comprehensive performance, and the application of a proper amount of scandium elements is innovative on the basis of traditional high-strength aluminum alloys or high-thermal-conductivity aluminum alloys. The alloy is suitable for 3C electronic products with high requirements for heat dissipation and strength, such as mobile phones and notebooks.

1. The name of the design product: portable Brinell hardness tester (with load display). 2. The use of the design product: the design product is used for measuring the hardness of metal materials, especially suitable for detecting metal workpieces with low hardness, coarse or uneven organization. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The asymmetrical magnet actuator comprises an asymmetrical shell, a rotatable permanent magnet, a control knob, a gear handle and a detachable sealing cover, the asymmetrical shell is of a hollow structure with an opening part and comprises a bottom plate and a top plate which are oppositely arranged, the bottom plate comprises a cambered surface plate in the middle and surface plates on the two sides, and the top plate is arranged on the cambered surface plate. The thickness of the cambered plate is smaller than that of the plane plate, and the thickness of the top plate is smaller than that of the cambered plate. The rotatable permanent magnet is rotatably contained in the hollow structure, one end of the control knob is connected with the rotatable permanent magnet, the other end of the control knob is connected with the gear handle, the gear handle can swing clockwise or anticlockwise around the axial direction of the rotatable permanent magnet, and the detachable sealing cover is matched with the opening part and detachably installed on the asymmetric shell. According to the scheme, the shell is of an asymmetric structure, magnetic lines converge at the top in a working state, the attraction force of the magnet is multiplied, a steel workpiece is easily lifted away in a non-working state, and the requirement for the Brinell hardness test force can be well met.

This invention discloses a method for preparing high-performance rare-earth wear-resistant steel with low rare-earth content, comprising: composition design: the chemical composition of the wear-resistant steel by mass fraction is: C 0.20-0.25%, Mn 1.2-1.5%, Si 0.4-0.6%, Cr 0.8-1.0%, Mo 0.2-0.3%, Ni 0.1-0.2%, rare earth (Ce+La, mass ratio 1:1) 0.03-0.05%, S≤0.005%, P≤0.015%; converter smelting; rare earth microalloying treatment; LF refining; continuous casting; controlled rolling and controlled cooling. This invention achieves a rare earth addition of ≤0.05%, a Brinell hardness ≥500HB, an impact toughness of -20℃ ≥120J / cm², and a wear resistance performance 1.8 times higher than traditional wear-resistant steel, while improving the product qualification rate to ≥98.5%, enabling large-scale stable production.

The invention relates to the technical field of heat treatment of wear-resistant flat steel, and discloses a heat treatment and hardness regulation and control process for arc flat steel of a wear-resistant plate of a high-wear-resistant excavator bucket, which comprises the following steps: S1, a pretreatment process, S2, a quenching process, S3, a tempering process, S4, a post-treatment process and S5, a hardness and performance detection process. Two quenching intervals of high hardness emphasis (1040-1080 DEG C) and toughness balance emphasis (850-890 DEG C) are set, and corresponding tempering parameters are matched, so that the surface Brinell hardness of 450-490 HBW is precisely regulated and controlled, the hardness difference value of the same workpiece is smaller than or equal to 20 HBW, the hardness requirement of a high-wear-resistance scene can be met, the method can be suitable for an operation environment with the requirement for toughness, and the service life of the workpiece is prolonged. The problem of single hardness regulation and control in the traditional process is solved.

The application discloses a steel plate material resistant to 500 DEG C and hydrogen sulfide environment, which comprises the following components in percentage by weight: C: 0.06%-0.10%, Si: 0.20%-0.50%, Mn: 0.30%-0.60%, Cr: 4.0%-6.0%, Mo: 0.40%-0.80%, V: 0.05%-0.10%, and N: 0.010%-0.030%. The preparation method comprises the following steps: smelting, casting, heating, rolling, and decomposing bainite through tempering after normalizing, and then stabilizing treatment. The steel plate material prepared by the application has the tensile strength of 380-410 MPa at 500 DEG C, the transverse elongation of 34.0-36.5%, the longitudinal elongation of 36.5-38.5%, the Brinell hardness of 160-170, the yield strength ratio of 0.73-0.75, and the SSCC four-point bending test continuous loading of 720h without fracture.

This application belongs to the field of steel materials technology, specifically to an NM450 grade wear-resistant steel and its production method. The NM450 grade wear-resistant steel has a Brinell hardness of 435HBW-460HBW. The NM450 grade wear-resistant steel comprises the following components by weight percentage: C: 0.19%-0.22%, Si: 0.35%-0.55%, Mn: 1.25%-1.40%, P≤0.012%, S≤0.003%, Cr: 0.30%-0.75%, Nb: 0.010%-0.020%, Ti: 0.012%-0.022%, B: 0.0012%-0.0023%, As≤0.007%, Als: 0.025%-0.050%, N≤0.0050%, with the remainder being Fe and impurities.

The invention relates to the technical field of hardness detection, and discloses a universal milling Brinell hardness tester for medium and small parts. A milling component, a hardness test component and an image acquisition component are sequentially arranged on the transverse slide carriage component, the milling component is used for milling the surface of a workpiece to be tested, and a test ball pressure head is arranged at the bottom of the hardness test component and is used for carrying out a Brinell hardness test; the hydraulic clamping component is arranged on the gantry rack, the hydraulic clamping component comprises a supporting seat fixed to the gantry rack, a fixed clamp body installed on one side of the supporting seat and a movable clamp body arranged on the other side of the supporting seat, bases are fixed to the opposite sides of the fixed clamp body and the movable clamp body, and clamping units are arranged on the inner sides of the bases. By arranging the clamping unit composed of the multiple sets of clamping blocks capable of independently moving, self-adaptive attachment can be conducted according to the irregular contour of a workpiece, and the problem that a traditional rigid jaw is poor in adaptability to clamping of complex small and medium parts is solved.

Portable hardness tester (1) for standard-compliant hardness testing according to the Rockwell, Vickers and / or Brinell methods, comprising: -a beak-like clamping system (2) for clamping an object to be measured, consisting of a hold-down device (26), a counter-holder (22) and an approach device (10, 12, 14, 16, 18, 20); -a unit (3) pivotably attached to the clamping system by means of a solid or leaf spring joint (20a), consisting of a spring body (36), a reference structure (34) and an indenter (48), as well as a measuring means (4) for determining the displacement of the indenter relative to the surface of the object to be measured; - a device (50, 50a, 50b) attached to the clamping system for applying a load to the spring body, which the spring body transfers to the indenter and thereby deforms the spring body relative to the reference structure; and a load determination means (5) which indicates the load exerted on the indenter by measuring the displacement of a point of the spring body relative to the reference structure;

This invention belongs to the field of steel smelting technology, specifically relating to an isothermal normalizing process for gear steel. Addressing issues such as uneven hardness, difficulty in achieving hardness standards for some steel grades, and low temperature control precision in batch processing of 20MnCr5 and 20CrMnTiH round steel during heat treatment, this invention achieves efficient batch processing of steel through a combination of precise furnace loading design, controlled heating time for each furnace cycle, coordinated temperature control via the cooling system, and precise and stable isothermal temperature control. After treatment, the steel's microstructure consists entirely of ferrite and pearlite (F+P), with no abnormal structures such as bainite or martensite, and a grain size reaching level 8. The Brinell hardness of the round steel remains stable above 150 HBW, fully meeting industry requirements. This process is compatible with existing conventional heat treatment equipment, requiring no additional equipment investment. Nitrogen cooling achieves oxidation-free decarburization of the steel, demonstrating feasibility and promotional value for large-scale industrial production.

The application discloses a preparation method of a high-strength fastener precipitated hardening stainless steel cold-drawing material, which comprises the steps of alloy ingredient mixing, vacuum smelting, electroslag remelting, hot working treatment, cold deformation strengthening, solid solution treatment and grading aging treatment. The stainless steel material prepared by the application has a tensile strength of no less than 1420 MPa, a yield strength of no less than 1280 MPa, an elongation after fracture of no less than 12.5%, and a Brinell hardness of no less than 430 HB, and simultaneously has excellent atmospheric corrosion resistance and medium corrosion resistance, and is suitable for the severe requirements of high-strength fasteners in the fields of aerospace, high-end equipment, ocean engineering and the like. The process has the advantages of high stability, high repeatability and convenience for industrialized batch production.

The invention discloses a production method of a high-hardness and high-toughness wear-resistant steel plate. The production process comprises the steps of molten iron pretreatment, converter treatment, LF and RH / VD refining, continuous casting, heating, rolling, finishing and quenched-tempered heat treatment. The steel plate comprises the following chemical components in percentage by weight: 0.2-0.35% of C, 0.5-2.0% of Mn, 0.5-1.5% of Si, less than or equal to 1.0% of Ni, less than or equal to 2.0% of Cr, 0.2-1.5% of Mo, less than or equal to 0.5% of Cu, less than or equal to 0.020% of P, less than or equal to 0.005% of S, 0.001-0.005% of B and the balance of Fe and inevitable impurity elements. According to the invention, a multi-phase composite structure of tempered martensite, tempered bainite and retained austenite is realized by combining novel alloy component design with controlled rolling and heat treatment processes, and the high-hardness and high-toughness wear-resistant steel plate with yield strength greater than or equal to 1150 MPa, tensile strength greater than or equal to 1450 MPa, total elongation greater than or equal to 10%, brinell hardness greater than or equal to 460 HBW and ballistic energy greater than or equal to 40 J at-20 DEG C is obtained.

A cylinder housing characterized in that the cylinder housing is an aluminum metal housing or an aluminum alloy housing comprising an end plate and a side plate, wherein the end plate is a circular end plate, wherein the side plate is provided in a circumferential direction of the end plate and extends in an axial direction of the cylinder housing; wherein a transition section is provided between the end plate and the side plate, the transition section comprising an arc-shaped segment; wherein a ratio of a dimension of the transition section in the axial direction of the cylinder housing to a dimension of the transition section in a radial direction of the end plate is L; wherein a radius of the arc-shaped segment is R, wherein a Brinell hardness of the housing is H; wherein a relationship between R, H and L 0 ≤ H*|L-1| / R ≤ 28 satisfies; wherein the unit of R is mm, the unit of H is HB and the range of L is 0.6 to 1.4.

The application discloses a kind of conical pipe processing method and supporting core, belong to machining technical field.The method includes: prefabricated straight pipe material;Supporting core is made of soft material, its outer diameter is greater than the inner hole of straight pipe material to form interference fit;Supporting core is inserted into one end of straight pipe material;The end portion inserted with supporting core is carried out rotary swaging and is formed conical surface;Remove supporting core;Conical surface is finished.The supporting core is made of soft material with Brinell hardness ≤30HBW, and symmetrical guide conical surface is provided at both ends thereof.The supporting core with soft interference fit supports the inner wall and forms a guide during rotary swaging, and can be easily removed by turning after processing, effectively solves the problem that slender conical pipe parts cannot be turned due to insufficient tool rigidity, and significantly improves the machining precision and the qualified rate.

The invention belongs to the technical field of steel and iron materials, and particularly relates to NM450-grade wear-resistant steel and a production method thereof, the Brinell hardness of the NM450-grade wear-resistant steel is 435 HBW-460 HBW, and the NM450-grade wear-resistant steel comprises, by weight, 0.19%-0.22% of C, 0.35%-0.55% of Si, 1.25%-1.40% of Mn, smaller than or equal to 0.012% of P, smaller than or equal to 0.003% of S, 0.30%-0.75% of Cr, 0.010%-0.020% of Nb, 0.012%-0.022% of Ti, 0.0012%-0.0023% of B, smaller than or equal to 0.007% of As, 0.025%-0.050% of Als, smaller than or equal to 0.0050% of N

The application relates to the technical field of hardness detection, and discloses a general milling Brinell hardness tester for middle and small parts, which comprises a gantry frame, a transverse sliding plate component, a milling component, a hardness test component and an image acquisition component which are sequentially arranged on the transverse sliding plate component, the milling component is used for milling the surface of a workpiece to be measured, the hardness test component is provided with a test ball indenter at the bottom for Brinell hardness testing, and a hydraulic clamping component is arranged on the gantry frame and comprises a supporting seat fixed on the gantry frame, a fixed jaw body arranged on one side of the supporting seat and a movable jaw body arranged on the other side of the supporting seat, a base is fixed to the opposite side of each of the fixed jaw body and the movable jaw body, and a clamping unit is arranged on the inner side of the base. The clamping unit composed of multiple groups of clamping blocks capable of independently moving can be adaptively attached according to the irregular contour of the workpiece, and the problem of poor adaptability of the traditional rigid jaw to the clamping of complex middle and small parts is solved.

The application discloses a Brinell hardness automatic detection system and a detection method thereof and belongs to the technical field of Brinell hardness detection. The system comprises an integrated unit, a feeding unit, a transfer unit, a polishing unit and a Brinell hardness detection unit, and the integrated unit controls the feeding unit, the transfer unit, the polishing unit and the Brinell hardness detection unit. The feeding unit comprises a transmission track and a turnover box, a transmission belt is arranged on the outer periphery of the transmission track, a visual sensor support is arranged on the transmission track, a clamping device is arranged below the transmission track, an optical identification system is arranged on the support, the turnover box can move with the transmission belt, and the transfer unit can transfer the parts in the turnover box to the polishing unit. The system does not need to design a special clamp according to the parts to be detected, the turnover box is transmitted through the transmission belt, the position of the parts is recognized and positioned through the optical identification system, the automatic detection of the parts with complex structures can be completed, and the system is suitable for the automatic hardness detection of parts with multiple specifications and complex shapes.

This invention discloses a method for measuring Brinell hardness by indentation, comprising: S1, selecting two hardness standards, wherein the hardness value of the sample to be tested is within H... BW 1 and H BW Between 2; S2, use the sample to be tested to perform indentation testing on the testing machine to obtain the corresponding maximum indentation depth h. max 1. h max 2. The test load F is used to calculate the indentation depths h1 and h2; S3. Using h1, h2, and h max 1. h max 2. Based on F, two sets of stiffness data K1 and K2 of the testing machine are obtained; S4. Based on K1 and K2, the corrected stiffness K of the testing machine is obtained. m S5. Obtain the maximum indentation depth h of the sample to be tested. max 3. According to h max 3. K m Obtain the corrected indentation depth h3; S6, derive the Brinell hardness H of the sample based on h3. BW 3. By incorporating the above measurement methods into a program, automated stiffness correction and automated hardness testing can be achieved.

A kind of production method of large-thickness NM600 steel plate, the chemical composition of steel is as follows: C=0.43%~0.45%, Si=0.10%~0.20%, Mn=0.95%~1.05%, P≤0.008%, S≤0.0015%, Cr=1.05%~1.15%, Mo=0.14~0.18%, Ti=0.008%~0.015%, V=0.030%~0.040%, Alt=0.050%~0.070%, B=0.0008%~0.0020%, broken space H≤0.00010%, ladle H≤0.00012%, N≤0.0035%, O≤0.0015%, and the rest is Fe and inevitable impurities.The present application is produced by 260mm casting blank, through reasonable casting, rolling and heat treatment process, produces maximum thickness 80mm NM600 high-grade wear-resistant steel, surface Brinell hardness 570~640HB, yield strength ≥1600MPa, tensile strength ≥2000MPa, elongation ≥7%, improves the service performance of wear-resistant steel in heavy load field such as mine machinery, engineering equipment.

The invention discloses a Brinell hardness reference device, which belongs to the technical field of Brinell hardness testers, and comprises a base, a lower support column arranged on the upper surface of the base, a middle beam mounted on the top of the lower support column, an upper support column arranged on the middle beam, an upper beam mounted on the top of the upper support column, and a servo motor mounted on the upper beam, a feedback force sensor is mounted at the lower end of the upper pull rod; a lower pull rod is connected to the lower end of the feedback force sensor; a hanging assembly is mounted at the lower end of the lower pull rod; a weight is mounted at the lower end of the hanging assembly; a pressing head is installed on the hanging assembly and located above the weight, the pressing head is connected with a main shaft, an upper air bearing is installed on the main shaft, a workbench is installed on the middle beam and located below the pressing head, and a load changing assembly is further installed on the base and located beside the weight. According to the device, the precision and the stability of Brinell hardness value measurement are greatly improved.

The invention discloses a high-density copper-tin alloy powder metallurgy process in the field of powder metallurgy, which comprises the following steps: step 1, raw material preparation: weighing 90% of copper powder, 9.510.5% of tin powder and 0.1% of lubricant according to mass percent; through multi-dimensional innovation of raw material particle size matching (copper powder is 5-15 microns / tin powder is 3-8 microns), composite lubricant (zinc stearate: graphite = 1: 1) application, segmented sintering, high-pressure re-pressing (800-900 MPa) and aging treatment, the product density is improved to 8.2 or above (up to 8.42) from 7.2 of a traditional process, the tensile strength is improved to 410-435 MPa from 320 MPa, the Brinell hardness is improved to 82-88 HB from 65 HB, and the product quality is improved. Meanwhile, tin segregation and residual stress are eliminated through uniform powder mixing and aging treatment, the process stability and the product size precision are improved, special equipment does not need to be newly added, the product additional value is increased by 30% or above while the production cost is increased by 5% or less, and the requirements of high-end fields such as high-speed rails and deep sea equipment can be met; the core problems of low density, poor performance and short service life of the traditional copper-tin alloy are effectively solved.

The application discloses a low-alloy wear-resistant steel with large thickness and high Brinell hardness and a preparation method thereof, and chemical components and mass percentages of the low-alloy wear-resistant steel are as follows: Cr: 0.90-1.20%, Ni: 0.80-1.2%, Ti: 0.008-0.030%, Nb: 0.015-0.050%, B: 0.0008-0.0025%, N: ≤0.0040%, O: ≤0.0025%, C: 0.34-0.38%, Si: 0.10-0.30%, Mn: 0.35-0.70%, Mo: <0.20%, P: ≤0.010%, S: ≤0.0015%, H: ≤0.0001%, Re: ≥0.0010%, and the rest is Fe and inevitable impurities. The application adopts reasonable component design, adopts high-carbon and alloying component design, and through mutual cooperation of carbon, manganese, chromium, nickel, molybdenum and other alloy elements and niobium, titanium and other micro-alloy elements, good hardness and low-temperature toughness matching are obtained.

The utility model relates to hardness detection frock technical field, the utility model provides a portable lifting type Brinell hardness detection device, it includes base, hardness tester bracket and sliding adjustment unit, base detachable setting on the workstation for placing work piece, hardness tester bracket sliding setting on the base, and hardness tester bracket is used for carrying Brinell hardness tester, sliding adjustment unit sets up on the base, is used for adjusting hardness tester bracket, and makes hardness tester bracket relative to base sliding. Through the above technical scheme, in the related art, when the desktop hardness detection equipment of general indoor determines large work piece, the work piece transportation time -consuming, work piece fixing difficult etc. Problem. Overall reduce the transportation difficulty of large work piece, reduce the transportation time of work piece, improve the determination efficiency of work piece, simultaneously convenient on -the -spot to the hardness of various work piece including special -shaped spare determination.

The application discloses a kind of marine medium-voltage DC hybrid circuit breaker's solid seal pole temperature rise characteristic simulation method, comprising the following steps: (1) constructing the three-dimensional structure model of marine medium-voltage DC hybrid circuit breaker solid seal pole;(2) the equivalent model of contact resistance in three-dimensional structure model different contact interface is established, which is based on Holm formula, the size and conductivity of conductive bridge are determined by combining the parameters of brinell hardness and contact pressure of contact material, and the contact resistance of bolt connection is calculated according to pre-tightening force and tightening torque;(3) multi-physical field coupling simulation: electromagnetic-heat flow coupling method is used to establish external air domain and set pressure outlet to simulate natural convection, map the power loss distribution obtained by electromagnetic field calculation to heat flow field, and solve to obtain the steady-state temperature field of solid seal pole.The application constructs the equivalent model of contact interface in line with actual physical mechanism, and solves the error and cost problems caused by the simplification of contact resistance in traditional method or the dependence on experimental calibration.