68 results about "Invar alloy" patented technology

The invention discloses a forging method for improving plasticity of a large invar alloy steel ingot and invar alloy, and the forging method comprises the following steps: smelting molten steel by adopting an electric furnace, and casting to obtain the large invar alloy steel ingot with the weight of 15-25t; the cold-state invar alloy steel ingot is heated to 1000-1200 DEG C for heat preservation, and the heat preservation time is controlled to be longer than or equal to 10 h; the heated invar alloy steel ingot is subjected to three-heating-number upsetting and drawing-out, upsetting is conducted according to the rolling reduction of 15-50% of the total height of the invar alloy steel ingot in each heating number, the invar alloy steel ingot is drawn out to the height of the original invar alloy steel ingot after upsetting, and the invar alloy steel ingot is returned to a heating furnace to be heated and subjected to heat preservation after upsetting and drawing-out in each heating number; the final forging temperature of the last heating number is greater than or equal to 750 DEG C; and the invar alloy steel ingot subjected to heating and heat preservation in the last heating number is forged to the specified size, and then the invar alloy steel ingot is slowly cooled to the room temperature in air to obtain an invar alloy steel forging stock. The thermoplasticity of the large invar alloy steel ingot is improved, and the technical problem that the large invar alloy steel ingot is prone to cracking during forging is solved.

According to the smelting method for refining the size of the inclusions of the invar alloy and the invar alloy, a large-size invar alloy steel ingot is prepared through the processes of induction furnace smelting, AOD furnace refining, LF furnace refining, VD furnace refining and die casting, in the AOD furnace refining process, an Al-Si-Mn composite deoxidizing agent is adopted for deoxidizing, in the LF furnace refining process, Ni-Mg alloy is added, and in the VD furnace refining process, the Al-Si-Mn composite deoxidizing agent is adopted for deoxidizing; the impurities are decomposed and refined, the impurities are controlled to be Al2O3-MgO-SiO2 series impurities, the grade of the A type impurities, the grade of the B type impurities, the grade of the C type impurities and the grade of the D type impurities are smaller than or equal to 0.5 grade, and the grade of the Ds type impurities is 0 grade. The method can effectively refine the size of the inclusions in the invar alloy molten steel, reduce the occurrence rate of local peeling defects on the surface of the cold-rolled strip caused by large-size deoxidized products, and improve the product quality and the yield of the invar alloy strip.

A method for manufacturing an FMM according to the present invention comprises: a step (a) for plating an invar alloy sheet on an object by electroplating; (b) arranging invar alloy sheets on one surface of a carrier film and attaching the invar alloy sheets; (c) forming a divided photoresist on the upper surface of the invar alloy sheet, etching the upper surface portion of the invar alloy sheet with an etching solution, and forming a first etched portion at the divided portion; (d) forming hole plugging ink on the upper surface of the invar alloy sheet to plug the first etching part; (e) turning over the invar alloy sheet in the vertical direction, and forming a photoresist on the upper surface of the invar alloy sheet; and a step (f) in which the upper surface of the invar alloy sheet is etched with an etching solution, a second etched portion is formed at the division portion, the lower portion of the second etched portion is in contact with the first etched portion to form a pattern hole, and steps (c) to (f) are continuously performed in a roll-to-roll manner in a state in which the invar alloy sheet is aligned on the upper portion of the carrier film and attached thereto.

The invention discloses a surface corrosion-resistant invar alloy precision strip for a liquid cargo cabin of a liquefied natural gas carrier and a manufacturing method. The surface corrosion-resistant invar alloy precision strip comprises the following components: 35.6%-37.1% of Ni, 0.35%-0.80% of Si, 0.05%-0.10% of Ce, 0.015%-0.030% of C, less than or equal to 0.35% of Mn, 0-0.0008% of O, less than or equal to 0.01% of N, less than or equal to 0.003% of S, less than or equal to 0.005% of P, less than or equal to 0.20% of Cr, less than or equal to 0.20% of Cu, less than or equal to 0.05% of Al, less than or equal to 0.003% of Ti and the balance of iron and inevitable impurity elements. According to the formula, through EAF, AOD, LF, continuous casting or die casting, hot continuous rolling or solid solution pickling after forging, cold rolling in multiple rolling processes, annealing and protective film prefabrication treatment, the temperature range of the prepared material is about 1.5-1.8 * 10 <-6 > / DEG C from-163 DEG C to 20 DEG C, the yield strength Rp0.2 value is larger than or equal to 300 MPa, the tensile strength Rm value is larger than or equal to 480 MPa, the ductility A50 is larger than or equal to 35%, surface corrosion does not occur within the machining period or storage and transportation time of 15 days under the conventional condition, and the service life of the material is prolonged. And particularly, the risk of surface rusting in the processing, storage and transportation processes is greatly reduced.

The invention discloses a high-surface-quality invar alloy cold-rolled steel strip and a manufacturing method thereof.The manufacturing method comprises the working procedures of acid pickling, cold rolling and pre-pressing, coping, cold rolling and rolling, cleaning, annealing, leveling, shearing and packaging, the surface of an invar alloy hot-rolled steel coil is subjected to acid pickling through a mixed acid solution, cold rolling and pre-pressing are conducted through three-pass cold rolling and rolling, and the surface quality of the invar alloy hot-rolled steel coil is improved. At least three pairs of grinding heads are adopted for grinding, the grinding frequency is not less than 3 times, multi-pass cold rolling is carried out after grinding, the number n of rolling passes meets the condition that n is larger than or equal to 0.5 * m + 1, m is the thickness of the ground cold-rolled steel strip, and the unit is mm. According to the method, the technical problems that the surface quality of the invar alloy cold-rolled strip is difficult to control, the requirement is high and the like can be effectively solved, invar alloy products with high surface quality and high plate shape requirement are prepared, and the high-surface-quality use requirement of a user is met.

The Fe-Ni-based invar alloy comprises the following chemical components in percentage by weight: more than or equal to 0.01% and less than or equal to 0.5% of C, more than or equal to 0.01% and less than or equal to 0.25% of Si, more than or equal to 0.2% and less than or equal to 0.4% of Mn, more than or equal to 0.01% and less than or equal to 0.1% of P, more than or equal to 0.01% and less than or equal to 0.2% of S, more than or equal to 30% and less than or equal to 37% of Ni, more than or equal to 0.2% and less than or equal to 0.6% of Al, more than or equal to 0.2% and less than or equal to 0.4% of Mg and the balance of Fe and inevitable impurities. According to the invention, alloy components are optimized, and processing is carried out through a two-stage thermal deformation process, so that on the premise of ensuring the expansion performance of the alloy, the thermal processing performance of the alloy is further improved, and the thermoplasticity of the alloy is improved.

The invention discloses equipment and a method for customizing front and back morphology structures of an invar alloy ultra-thin strip, and belongs to the field of invar alloy ultra-thin strip processing. The equipment comprises a working roller with differentiated surface topography, a first middle roller with a polyurethane-based organic material coating layer, an ultrasonic clamping device, an integrated tension weighting control system and a central control unit. By configuring different surface roughness of the upper working roll and the lower working roll and combining stable transverse pressure stress and axial ultrasonic vibration provided by the first middle roll, asymmetric plastic flow and shape copying of metal on the front face and the back face of the strip are achieved. In the rolling process, plate shape defects caused by friction differences are dynamically compensated by cooperatively adjusting the roll shifting amount of the first intermediate roll and the convexity of the backing roll saddle, finally, customized production of the 4J36 invar alloy ultra-thin strip with the thickness of 15 microns is achieved, the A face and the B face of the strip have different surface roughness, and the surface roughness of the strip is greatly improved. And the specific requirement of a fine metal mask plate pore-forming process on the surface state of the base material is met.

The invention relates to the technical field of strip rolling, and discloses a device for rolling an invar alloy ultra-thin strip by using a double-sided electrified auxiliary twenty-high rolling mill, which comprises a rolling mill, a double-sided electrified auxiliary twenty-high rolling mill, a double-sided electrified auxiliary twenty-high rolling mill, a double-sided electrified auxiliary twenty-high rolling mill, a double-sided electrified auxiliary twenty-high rolling mill and a double-sided electrified auxiliary twenty-high rolling mill, the electrifying resistance rollers are arranged on the left side and the right side of the rolling mill and connected with the upper surface or the lower surface of the strip, the electrifying resistance rollers are communicated with a power source, and the electrifying resistance rollers, the strip and the power source form a strip electrifying heating loop; a plurality of resistor elements are sequentially arranged in the electrified resistance roller in the length direction of the electrified resistance roller, the resistor elements are sequentially connected in series and connected with an external control center, the control center is used for controlling the resistance of the resistor elements, the electrified resistance roller is made of conductive materials, and the resistor elements are attached to the inner surface of the electrified resistance roller. The transverse temperature of the strip can be adjusted in a partitioned mode, and the problem of current instability is solved.

This invention discloses an Invar alloy steel ingot, its smelting method, and its applications, belonging to the field of alloy preparation technology. It solves the problems of low purity, large elemental segregation, numerous inclusions, and poor uniformity in existing Invar alloys. The composition of the Invar alloy steel ingot, by mass percentage, includes: Ni: 35.5%–36.5%, C ≤ 0.01%, Si: ≤ 0.05%, Mn: 0.30%–0.50%, Al: ≤ 0.02%, Mg: ≤ 0.05%, Zr: ≤ 0.05%, Ti: ≤ 0.05%, P: ≤ 0.005%, S: ≤ 0.001%, O: ≤ 0.0008%, N: ≤ 0.0005%, with the balance being Fe and other unavoidable impurities. The Invar alloy steel ingot of this invention has high purity, low impurity content, small elemental segregation, few inclusions, and good uniformity.

The application discloses a preparation method of large-size super-long invar alloy flat material, adopts four forging processes, and specifically comprises the following steps: first fire is used for head riser pretreatment, second fire is used for vertical ingot upsetting and octagonal shaping, third fire is used for secondary vertical ingot upsetting and multi-surface elongation, and fourth fire is used for finished product forging. Through segmented heating and forging cooperative control, the bottleneck problem existing in the forging process of the super-long specification is broken through, the large-size super-long invar alloy flat material with a weight of 25-30 t and a length of greater than or equal to 11 m is obtained, and the forging quality and production efficiency of the large-size super-long invar alloy flat material are significantly improved.

This invention discloses a bell-type annealing method for Invar alloy cold-rolled steel coils, comprising the following steps: S1, stacking Invar alloy cold-rolled steel coils in a bell-type annealing furnace, with metal heat transfer pads arranged between adjacent Invar alloy cold-rolled steel coils for isolation, the heat transfer pads having symmetrical groove structures; S2, during the bell-type annealing process, reducing sponge iron is placed in the bell-type annealing furnace, hydrogen is introduced, and the temperature is raised to 500-700℃ at a heating rate of 60-150℃ / h, then raised to 850-1000℃ at a heating rate of 20-50℃ / h and held for 20-40h, then cooled at a cooling rate of 20-40℃ / h, and removed from the furnace when the temperature inside the bell-type annealing furnace drops to less than 100℃; the flatness of the Invar alloy cold-rolled steel coils after bell-type annealing is ≤2.0mm / m. This invention can solve the problems of uneven stress release and easy oxidation of the edges due to uneven heating of Invar alloy strip.

The invention relates to a forecasting method suitable for deformation resistance in the invar alloy hot rolling process and application thereof, belongs to the field of hot rolling, and solves the problems that in the prior art, in the invar alloy hot rolling process, especially in the hot rolling and finish rolling process, deformation resistance forecasting is low in precision and large in deviation, and the plate shape and quality after hot rolling are difficult to guarantee. And a large amount of time and cost are required. The forecasting method comprises the following steps: collecting main equipment and process parameters of a hot rolling unit; invar alloy incoming material parameters and hot rolling process parameters are given; the outlet temperature of the jth pass is calculated; and determining the deformation resistance of the invar alloy in the jth pass. According to the method, accurate prediction of the deformation resistance in the invar alloy hot rolling process is achieved, and the accuracy error is small.

The invention discloses a method for preparing an ultra-high-purity invar alloy cast ingot based on forging diameter changing. The method comprises the following steps that firstly, a cast ingot is formed through vacuum electron beam melting; secondly, forging and diameter changing are conducted; according to the method, vacuum electron beam cold bed smelting, forging diameter changing and vacuum consumable remelting form a short continuous process, the prepared and formed invar alloy ingot has the advantages of being large in size, high in purity and grain size, uniform and compact in structure, few in defect and the like by optimizing parameters, and the short continuous process has the advantages of reducing the cost, improving the production efficiency and the like at the same time. And the efficiency is improved.

The invention discloses a heat conduction substrate with low interface stress and a preparation method thereof, and the method comprises the steps: providing a ceramic substrate which comprises a silicon nitride substrate, an aluminum nitride substrate, a diamond substrate or a silicon carbide substrate, and is provided with a first surface and a second surface which are oppositely arranged; providing at least one copper composite board; performing a copper coating process to arrange the at least one copper composite plate on at least one surface of the ceramic substrate so as to form a ceramic copper-clad plate to realize heat conduction; the copper composite plate comprises a metal plate made of invar alloy or kovar alloy, a transition metal layer formed on the metal plate and a copper layer formed on the transition metal layer, a plurality of up-down through micropores are formed in the metal plate, and the micropores are filled with copper materials. By adopting the heat-conducting substrate, the interface stress of the ceramic substrate and the copper-clad layer in the heat-conducting substrate at high and low temperatures can be reduced, the stability of the heat-conducting substrate is improved, and the service life of the heat-conducting substrate is prolonged.

The present application relates to a kind of oil grinding agent suitable for ultra-thin invar alloy plate, pickling pretreatment method and pickling process, belong to the field of metal material surface treatment, at least one of the problems such as incomplete removal of existing direct pickling process, high risk of matrix overcorrosion, low pickling efficiency and poor surface quality uniformity is solved.One kind of oil grinding agent suitable for ultra-thin invar alloy plate, the oil grinding agent includes mineral oil and extreme pressure agent, the mass ratio of mineral oil and extreme pressure agent is (8-12):1.The present application realizes efficient stripping loose oxide layer, reduces pickling chemical burden, avoids matrix overcorrosion, improves overall efficiency, homogenizes initial surface state, and guarantees final treatment uniformity.

The invention discloses an integral matrix type force transducer and a measuring method, the force transducer comprises a base mechanism, a thermal compensation mechanism, an elastic beam mechanism and a load mechanism, the base mechanism comprises a titanium alloy substrate and a honeycomb buffer layer, the honeycomb buffer layer is installed on the titanium alloy substrate, and the thermal compensation mechanism is installed on the base mechanism. A shear force dispersion unit is arranged between the titanium alloy substrate and the honeycomb buffer layer; the thermal compensation mechanism comprises a carbon fiber layer, a PZT piezoelectric layer and an invar alloy layer. According to the invention, through the innovative mechanical structure design, the measurement precision and the temperature adaptability of the whole matrix type force transducer are significantly improved; aiming at the problem of stress concentration, local stress of a load acting point is dispersed through dual effects of the base mechanism and the elastic beam mechanism, and nonlinear response of the strain gauges is eliminated; in order to solve the problem of thermal compensation failure, the thermal compensation mechanism breaks through the limitation of the consistency of thermal expansion coefficients of a traditional overall metal matrix through material isomerism and active deformation compensation.

The application relates to the technical field of metal plate composite technology and discloses a preparation process of a Kovar alloy-copper composite plate, which comprises the following steps: a preparation process of an Invar alloy-copper composite plate, which comprises the following steps: s1, taking one Invar alloy plate and two copper plates; s2, immersing the Invar alloy plate into liquid copper after the Invar alloy plate is heated to 250-300 DEG C; s3, positioning the two copper plates and the Invar alloy plate to form a group of initial composite plate materials; s4, heating the whole in a heating furnace, the heating temperature is 700-850 DEG C, and the heating time is 20-40 min; s5, taking out and cooling to 500-650 DEG C, and then performing hot rolling; s6, performing stress relieving annealing on the composite blank; s7, naturally cooling to normal temperature after annealing, and cold rolling to form an Invar alloy-copper composite plate with a preset thickness. The Invar alloy-copper composite plate prepared through the process is more stable and not easy to separate between the plates, the composite plate has the physical properties of the Kovar alloy and good thermal conductivity.

The present invention provides a method for manufacturing an FMM, the method comprising: step (a), electroplating Invar alloy sheets onto an object by means of electroplating; step (b), arraying and attaching the Invar alloy sheets on one side of a carrier film; step (c), forming a patterned photoresist on the upper surfaces of the Invar alloy sheets, etching the upper surface portion of the Invar alloy sheets by using an etching solution, and forming a first etched portion at a patterned portion; step (d), forming plugging ink on the upper surfaces of the Invar alloy sheets, and plugging the first etched portion; step (e), turning the Invar alloy sheets over along a vertical direction, and forming a photoresist on the upper surfaces of the Invar alloy sheets; and step (f), etching the upper surface portion of the Invar alloy sheets by using the etching solution, forming a second etched portion at the patterned portion, bringing the lower portion of the second etched portion into contact with the first etched portion to form pattern holes, and continuously performing step (c) to step (f) in a roll-to-roll manner in a state in which the Invar alloy sheets are arrayed and attached on the upper portion of the carrier film.

The application discloses a kind of super-thick invar alloy plate of uniform organization and manufacturing method thereof, 6-9t invar alloy steel ingot is prepared by electric furnace→AOD refining→LF refining→VD refining→IC die casting process;Nb element is added in AOD refining process;After that, invar alloy steel ingot carries out stress relief annealing, and adopts three times upsetting and drawing process, upsetting reduction is according to the principle of increment, gradually refines steel ingot surface and heart grain structure, ensures that steel ingot internal organization is fully broken after recrystallization, then forged to target size after annealing, obtains invar alloy plate of thickness ≥50mm after air cooling;The application can prevent the grain coarsening of the heart of super-thick invar alloy plate with thickness greater than 50mm, and obtain super-thick invar alloy plate with grain size ≥4 levels and uniform organization.

This invention discloses a Fe-Ni-Co-Cr-V-Nb-C-N multi-component Invar alloy and its preparation method. The alloy exhibits stable low expansion characteristics under different heat treatment conditions. In atomic percentage, the alloy is composed of the following chemical components: Fe 53-57%, Ni 21-24%, Co 15-17%, Cr 4-6%, V 0.1-1.0%, Nb 0.05-0.3%, C 0.4-1.0%, and N 0.05-0.3%. This invention yields a series of Fe-Ni-Co-Cr-V-Nb-C-N Invar multi-component alloys with significantly improved strength, solving the problem of low strength in traditional Invar alloys and further expanding the application range of Invar alloys in load-bearing environments.

The invention relates to the technical field of batteries, in particular to a battery. The battery comprises a shell and an electrode assembly, wherein the shell comprises a first through hole and a second through hole; the battery further comprises a pole structure and a pressure relief device, the pressure relief device comprises a sealing piece, a first connecting piece and an acting piece, the sealing piece covers the first through hole, the acting piece is located on the side, away from the first through hole, of the sealing piece, the first connecting piece is connected with the sealing piece and the side wall of the shell, and the first connecting piece and the acting piece are arranged in a spaced mode in the first direction; the acting piece is made of at least one of a bimetallic strip, memory alloy and invar alloy; the battery comprises an electrolyte, the electrolyte comprises fluorocarboxylic ester, and the mass content of the fluorocarboxylic ester is 5-70% based on the mass of the electrolyte. The pressure relief device of the battery not only can play a role in sealing and waterproofing when the battery is normally used, but also can play a role in timely exhausting and pressure relief when the battery is in a high-temperature environment.

The present application relates to a kind of carbon fiber wing main force C type long beam manufacturing method, comprising: S1. the Invar alloy steel with small thermal expansion coefficient is selected, and forming mould is made by five-axis numerical control milling equipment;S2. carbon fiber woven fabric prepreg and carbon fiber unidirectional tape prepreg of medium temperature system are alternately laid and stacked on the forming mould of S1, and the wing long beam of entire C type structure is made;S3. the wing long beam of S2 laying and stacking is bagged, and is cured into shape in curing oven.Through the method, the problem of manufacturing difficulty of full composite wing main force C type long beam is solved, and by using carbon fiber woven fabric prepreg and carbon fiber unidirectional tape prepreg of medium temperature system, the face profile of curing and forming long beam and the deformation amount of effective control are guaranteed by using Invar alloy steel with little deformation with temperature variation, the quality of long beam is improved, and the energy consumption cost of the same temperature hot press tank process is reduced.

The application provides a heating method for improving the thermal plasticity of inconel alloy and application thereof, wherein the heating method comprises the following steps: a first heating stage: inconel alloy continuous casting billets are heated to the lower limit temperature of the corresponding Curie temperature range at a first heating rate; a second heating stage: the inconel alloy continuous casting billets treated in the first heating stage are heated to the upper limit temperature of the corresponding Curie temperature range at a second heating rate; the second heating rate is less than the first heating rate; a third heating stage: the inconel alloy continuous casting billets treated in the second heating stage are heated to the holding temperature of 1150-1300 DEG C at the first heating rate and are held. The application slows down the heating of the inconel alloy continuous casting billets by the relatively low second heating rate, slows down the volume expansion rate of the inconel alloy continuous casting billets, and further reduces the internal stress of the inconel alloy continuous casting billets and the possibility of micro-crack generation, so that the thermal plasticity of the inconel alloy continuous casting billets is improved.

A lightweight high-thermal-stability joint based on invar alloy comprises a support, a joint framework and a connecting frame, and the joint framework and the connecting frame are connected through the support and driven by a driving assembly to rotate around the axis of a space joint. According to the space axis joint configuration, two joints with the axes in the orthogonal direction can be simplified into one space axis joint, the target position and posture can be reached through one-time rotation, the number and the movement frequency of the joints are reduced, and optimization of joint composition is achieved; according to the method, a topological structure optimization technology is combined, a lightweight joint structure of an irregular geometric structure is provided, and on the premise that rigidity and strength are not changed, part of materials are removed, and joint weight reduction is achieved; the 3D printing technology based on variable skin thickness design is further adopted for manufacturing a support, a joint framework and a connecting frame, high-surface-quality, high-internal-quality and high-dimensional-precision special-shaped part forming is achieved, and the weight is further reduced; the invar alloy powder is used as a raw material, and high thermal stability is achieved.

The invention discloses a power blade invar alloy forming mold preparation method and a forming mold, the forming mold comprises a suction surface forming mold, and the suction surface forming mold preparation method comprises the steps that invar alloy is adopted to prepare a main body frame of the suction surface forming mold; invar alloy is adopted as a skin panel, and the skin panel is heated and then pressurized and shaped; the shaped skin panel is welded with the main body frame; and the welded blank body is subjected to heat treatment to eliminate internal stress generated in the welding process. An invar alloy metal plate is adopted for shaping, a molded surface and a back frame are welded and formed, the size of the invar alloy is kept stable in a high-temperature environment due to the low thermal expansion coefficient of invar alloy, and the manufacturing method is particularly suitable for manufacturing large power blades. After welding is completed, internal stress generated in the welding process is eliminated through heat treatment, the overall strength and stability of the die are enhanced, the service life is prolonged, the reliability is improved, the power blade bearing high loads is not prone to deformation during forming, and the product quality is improved.

The application discloses a forging method for improving plasticity of large-size Invar alloy ingot and an Invar alloy. The method comprises the following steps: smelting molten steel by using an electric furnace, and obtaining a large-size Invar alloy ingot with a weight of 15-25 t after casting; heating the cold Invar alloy ingot to 1000-1200 DEG C and keeping the temperature, and controlling the keeping time to be greater than or equal to 10 h; performing three times of upsetting and elongating on the heated Invar alloy ingot, and performing upsetting according to 15-50% of the total height of the Invar alloy ingot in each time, then elongating to the original height of the Invar alloy ingot after the upsetting, and returning to the heating furnace for heating and keeping after the upsetting and elongating in each time; the final upsetting temperature is greater than or equal to 750 DEG C; the Invar alloy ingot after the heating and keeping in the last time is forged to a specified size, and then slowly cooled to room temperature in air to obtain an Invar alloy forging blank. The application improves the hot plasticity of the large-size Invar alloy ingot, and solves the technical problems of easy cracking of the large-size Invar alloy ingot during forging.

The invention belongs to the field of metal materials, and mainly relates to an ultralow-expansion invar alloy for the low-temperature field and a preparation method of the ultralow-expansion invar alloy. The Fe-Ni-based invar alloy composition system is subjected to composition optimization, the Ni element content in the alloy is reduced, a proper amount of Co element is added, it is guaranteed that the Ms point temperature of the alloy is lower than the service temperature of 260 DEG C below zero, and it is guaranteed that martensite phase transformation does not occur to the alloy at the service temperature of 260 DEG C below zero. And meanwhile, the Nb alloy element is added into the alloy, so that the grain boundary binding force of the as-cast structure of the steel ingot is strengthened, and the hot working plasticity of the large-specification steel ingot is further improved. Wherein the Nb element content is required to meet 0.01 (wt%) + 0.1% < = Nb (wt%) < = 0.03 (wt%) + 0.1%, and meanwhile, the first fire forging starting temperature of the alloy is required to be lower than 1050 DEG C, so that secondary carbide NbC is separated out during steel ingot forging, and the grain boundary binding force of a steel ingot as-cast structure is further improved.

This application provides an electropolishing method for Invar alloy substrates, specifically tailored to the surface characteristics of Invar alloy substrates thinned by ferric chloride reduction. The method involves using the Invar alloy substrate to be treated as the anode and a pure lead plate as the cathode, simultaneously immersing both the anode and cathode in an electrolytic tank containing an electrolyte for electropolishing. The electrolyte comprises phosphoric acid, sulfuric acid, malic acid, ethylene glycol, sodium dodecylbenzenesulfonate, and deionized water in a volume ratio of 6:1:1:1:0.5:0.5. Electropolishing the Invar alloy substrate thinned by ferric chloride using the above electrolyte composition and ratio yields an Invar alloy substrate with excellent surface quality. After polishing, the surface gloss of the Invar alloy substrate is increased to ≥92 GU, exhibiting a uniform and bright mirror-like effect.

The invention provides an invar alloy with an ultralow expansion coefficient and a precision machining method thereof.The invar alloy is composed of 35.9%-36.3% of Ni, 0.08%-0.12% of Ti, 0.02%-0.04% of Al, 0.003%-0.008% of B and the balance Fe, double VIP + VAR ultra-high-purity smelting, large-deformation multi-directional forging + solid solution structure refining, unique low-temperature stepped aging stabilization, liquid nitrogen ultra-precision cutting and low-heat input laser welding are combined, and the ultra-low expansion coefficient invar alloy is obtained. The invar alloy with ultralow expansion coefficient and high purity is prepared, and the problems of coarse grains and abrupt performance change of a welding area are effectively solved.

This application relates to the field of diamond tool manufacturing technology, and discloses a heat-fatigue-resistant ceramic tile diamond saw blade and its preparation process. The heat-fatigue-resistant ceramic tile diamond saw blade includes a base steel disc and a diamond cutting head welded to its outer edge. The cutting head is made of a mixture comprising: a base matrix powder consisting of 40-50 parts of pre-alloyed copper-nickel alloy powder, 25-35 parts of elemental iron powder, 8-12 parts of elemental cobalt powder, and 13-17 parts of elemental tin powder; 5-10% Invar alloy powder, 1-3% elemental molybdenum powder, and 0.5-1.0% titanium hydride powder added according to the total weight of the base powder; and uncoated single-crystal diamond particles accounting for 15-25% of the total volume of the sintered cutting head. This invention uses a technical solution of pre-alloyed copper-nickel alloy powder combined with Invar alloy powder to adjust the matrix expansion rate, achieving the technical effect of reducing the alternating stress at the interface between diamond and metal binder.