208 results about "Electro-slag remelting" patented technology

The invention discloses a pickling-free cold heading Kovar alloy wire production process which comprises the following steps: S1, raw material preparation: preparing the following raw materials in percentage by mass: 41.5% of Ni, 0.5% of Co, less than or equal to 0.03% of C, less than or equal to 0.05% of Mn, less than or equal to 0.05% of Si, less than or equal to 0.02% of P, less than or equal to 0.02% of S and the balance of Fe; mixing the materials, and carrying out vacuum induction melting and electroslag remelting to prepare an alloy ingot; the alloy cast ingot is subjected to hot rolling treatment to form a hot-rolled wire rod with the diameter being 12.0-16.0 mm; s2, peeling treatment is conducted, specifically, surface layer defects of the hot-rolled wire rod in the step S1 are removed through a peeling machine; s3, dry-type drawing treatment is conducted, specifically, the hot-rolled wire rod treated in the step S2 is subjected to dry-type drawing through a dry-type drawing die to form an alloy wire; s4, intermediate annealing treatment is conducted, specifically, the alloy wire in the step S3 is placed in an annealing furnace, sufficient hydrogen is input into the annealing furnace, intermediate annealing is conducted under the hydrogen protection atmosphere, the annealing temperature is 950-1100 DEG C, and the annealing walking speed is 3-5 m / min; the surface quality and the size consistency of the wire can be improved, meanwhile, the defects of environmental pollution, hydrogen embrittlement and the like are reduced, and the use requirements of high-end precise cold heading parts are met.

The invention discloses a meta-model decision-making-based intelligent prediction method for inclusion quality in an electroslag remelting process. The method comprises the following steps of: constructing a sample data set containing process and component characteristics and target variables; obtaining a first-layer basic model based on an SHAP value cumulative contribution rate screening method; a heterogeneous learner is adopted to construct a first layer structure of the stacked integrated learning model, and Bayesian is adopted to carry out adjustment and optimization; adopting logistic regression as a meta-learner to construct a second-layer structure of the stacked integrated learning model; training by adopting a five-fold cross validation strategy, and predicting the performance by using a multi-index quantitative model; and deploying the D-type inclusion prediction model in the electroslag remelting process to an actual process, collecting process parameters as input data in real time by using a multi-sensor group, performing D-type inclusion risk prediction of a corresponding heat, and outputting an inclusion risk prediction result. According to the method, the accuracy and reliability of D-type inclusion prediction can be remarkably improved.

The application discloses a device for reducing fluorine-containing gas pollutant emission in electroslag remelting and a use method, which comprises a flue gas recovery cover (1), a flue gas discharge pipeline (7) and a purification tank (10). The flue gas recovery cover (1) is respectively provided with a remelted slag discharging hole (2), a self-consuming mother electrode (6) passing hole and a flue gas discharge pipeline (7) mounting hole. The flue gas discharge pipeline (7) is arranged through the flue gas discharge pipeline (7) mounting hole, one end of the flue gas discharge pipeline (7) is located in a closed space formed by the flue gas recovery cover (1) and a crystallizer (5), and the other end is inserted into the purification tank (10). A fan (8) is arranged on the flue gas discharge pipeline (7). Through the device, the fluorine-containing flue gas is recovered, and the fluorine-containing flue gas is converted into calcium fluoride by using an alkali solution. The device can realize the cyclic and repeated use of part of the calcium fluoride, greatly reduces the concentration of fluorine-containing harmful gas in the air environment of an electroslag remelting operation site, and makes the concentration of the fluorine-containing harmful gas reduce from the original 5.6 mg / m 3 to 0.02 mg / m 3 .

The invention discloses a method for reducing impurity element sulfur in cast high-temperature alloy return scraps, and belongs to the technical field of metal material smelting. The method comprises the following steps: carrying out vacuum induction melting on pretreated cast high-temperature alloy return scraps of the same mark to obtain a return scrap alloy induction ingot; surface oxide skin of the obtained return scrap alloy induction ingot is removed, a primary shrinkage cavity in the upper end is cut off, then the return scrap alloy induction ingot and an auxiliary electrode are coaxially welded, and a consumable electrode is obtained; and after the consumable electrode is baked, electroslag remelting is conducted under the protective atmosphere, and an electroslag ingot is obtained. On the basis of vacuum induction melting, the protective atmosphere electroslag remelting technology is further adopted for conducting deep purification melting treatment on the return scrap alloy ingot, the content of the impurity element S in the return scrap alloy ingot can be reduced to 0.5 ppm or below, and the content of the impurity element S in the return scrap alloy ingot reaches the level lower than the content of the element S in a new material; and the high-temperature oxidation resistance and corrosion resistance of the alloy can be obviously improved, and the fatigue, durability and other mechanical properties of the alloy are improved.

A preparation method for high-nitrogen austenitic stainless steel. The high-nitrogen austenitic stainless steel comprises the following chemical components in percentages by weight: carbon: ≤0.02%; silicon: 0.4-0.8%; manganese: 10.2-12.5%; chromium: 24.5-26.5%; nickel: 13.5-16.5%; molybdenum: 3.2-4.8%; nitrogen: 0.75-0.95%; phosphorus: ≤0.03%; sulfur: ≤0.0025%; vanadium: 0.016-0.022%; niobium: 0.026-0.034%; copper: 0.2-0.35%; aluminum: 0.01-0.02%; cerium: 0.015-0.025%; and the balance of iron and inevitable impurities. The preparation method comprises the steps of raw material charging, vacuum melting, refining, nitrogen-added alloying, deoxidation and desulfurization, casting, electroslag remelting, and secondary casting. The preparation is implemented by using the processes of smelting in a pressurized induction furnace and electroslag remelting under a protective atmosphere; and nitrogen is added by using a method in which a nitrogen alloy and pressurized nitrogen permeation are combined.

The application provides a heat treatment method of a Ni30 high-temperature alloy, and comprises the following steps: S1: producing an electrode bar: according to the chemical composition of the Ni30 alloy, metal raw materials are loaded into a non-vacuum induction furnace, current heating is carried out to melt at 1500-1600 DEG C, then pouring is carried out in an ingot mold, mold cooling is carried out, then demolding is carried out, and then air cooling is continuously carried out to room temperature, so that a solid solution electrode bar is obtained; S2: high-temperature solid solution: the solid solution electrode bar obtained in the step S1 is loaded into a heating furnace, heating is carried out to 1050-1150 DEG C, and then holding is carried out for 4-8 hours, then the furnace is discharged, and water cooling is carried out to room temperature, so that a solid solution electrode bar is obtained; S3: electroslag remelting smelting: the solid solution electrode bar obtained in the step S2 is subjected to electroslag remelting smelting, so that an electroslag ingot is obtained, and preparation is completed. Through the application, the problem that the Ni30 high-temperature alloy electrode bar prepared by the conventional heat treatment method has large stress, the process parameters are unstable in the electroslag remelting process, the quality of the electroslag ingot is unstable, and the material yield of forging is low is solved.

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

The invention discloses modified high-carbon alloy steel and a preparation method and application thereof, and belongs to the technical field of high-carbon alloy steel for aluminum alloy forming dies. The preparation method disclosed by the invention comprises the following steps: carrying out electroslag remelting on a high-carbon alloy steel rod to obtain a casting blank; carrying out thermoplastic deformation on the casting blank to obtain a blank; the blank is annealed, so that carbides in the blank are eliminated or become fine particles, spherical graphite can be separated out, and the modified high-carbon alloy steel is obtained; the particle size of the fine particles is smaller than 10 microns. According to the method, coarse and large carbides which are difficult to eliminate in the high-carbon aluminum alloy forming die steel containing strong carbide forming elements such as Cr, Mo and V or medium-strong carbide forming elements are subjected to rapid and basic graphitization through a thermoplastic deformation and high-temperature graphitization combined process; the technical problem that carbide decomposition and graphite precipitation control are difficult to realize in the existing method is solved.

A method for preparing a sealing ring material for ultra-supercritical steam turbines belongs to the field of metallic materials. A master alloy is prepared by vacuum induction melting, followed by gas-supported electroslag remelting to obtain an electroslag ingot. The composition of the electroslag ingot is (3.5–4 wt%) Fe, (7.5–8 wt%) Mn, (1.8–2.0 wt%) Nb, (1.5–1.8 wt%) Si, (1.9–2.1 wt%) Ti, (17–18 wt%) B, with the remainder being Co. The electroslag ingot is then processed into a sealing ring blank of the required size using conventional hot deformation technology, held at 250–280°C for 60–90 minutes, and then precision-machined to obtain the finished sealing ring. The material of this invention exhibits excellent wear resistance, corrosion resistance, and high-temperature resistance. Two highly hard submicron-scale dispersed reinforcing phases are formed in the Co matrix. These two reinforcing phases possess high hardness and high strength, and are small in size, ensuring excellent high-temperature resistance of the sealing ring. At application temperatures above 400°C, some Co... 54 B 40 Fe6 can dissolve into the matrix, causing the amorphous matrix lattice to expand, which is beneficial to improving the sealing performance of the sealing ring.

The invention discloses an electroslag smelting method of low-Si low-Al B-containing heat-resistant stainless steel. According to the electroslag smelting method, the qualification rate of head and tail components of a steel ingot of an electric furnace casting rod after electroslag remelting reaches 100% through a quaternary slag system, and the sum of a fine system and a coarse system of non-metallic inclusions meets the requirement of not higher than grade 3; the thermal stress and phase change stress cracking of the steel ingot is prevented through stress relief annealing of the steel ingot, the tensile stress generated due to thermal expansion and cold contraction in the cooling process of the steel ingot and the phase change stress generated due to structural transformation are eliminated through the low-temperature annealing process, the steel ingot is prevented from cracking during long-time storage or saw cutting, many defects in the prior art are overcome, and the quality of the steel ingot is improved. The method has a remarkable industrial application prospect.

This invention provides a high-strength, high-toughness martensitic precipitation hardening stainless steel fastener and its preparation method, belonging to the field of metallurgical technology. The fastener is made of X5CrNiCuMo15-06 steel, and its chemical composition, by mass percentage, includes: C: ≤0.05%, Cr: 14-16%, Ni: 6.0-7.0%, Cu: 1.25-1.75%, Mo: 0.5-1.0%, Mn: ≤1.0%, Si: ≤1.0%, P: ≤0.008%, S: ≤0.005%, V: ≥8%C, with the balance being Fe and unavoidable impurities. This invention utilizes an ultra-low C+V microalloying composition design, a dual high-purity smelting process of vacuum induction and protective atmosphere electroslag remelting, combined with an integrated heat treatment system of solution treatment, deep cryogenic treatment, and aging treatment. This allows the material to maintain high strength while achieving excellent room temperature and ultra-low temperature toughness. The fasteners prepared can meet the high load-bearing and long-term service requirements of high-end equipment.

The invention discloses a slag charge for rare earth steel electroslag remelting and a preparation method, the slag charge comprises the following components in percentage by mass: 40%-60% of CaF2, 20%-35% of Al2O3, 5%-10% of CaO, 10%-15% of a rare earth mixture and 3%-5% of Na2O, the rare earth mixture is a mixture of Ce2O3 and La2O3, and the mass ratio of Ce2O3 to La2O3 is 2: (0.5-1.5); the preparation method comprises the following steps: selecting and pretreating raw materials, proportioning and pelletizing, and packaging slag balls for later use; the rare earth oxide is added into the slag charge, so that oxidation of rare earth in the electroslag remelting process can be inhibited, the yield of the rare earth is increased, the yield of the rare earth in steel is increased to 80%-90% and is increased by 20%-30% compared with that of traditional slag charge, and therefore the content of the rare earth in the steel can be more accurately controlled, and the stability and consistency of the performance of the rare earth steel are guaranteed.

The application relates to the technical field of alloy steel, in particular to a rare earth-containing high-strength corrosion-resistant cutter alloy steel and a preparation method thereof. Fe is used as a matrix, and the alloy steel contains C, Si, Mn, Cr, Mo, V, Nb, N, composite rare earth and TiB2, the contents of P and S are controlled in an extremely low range; the composite rare earth is a mixture of La and Ce, the content and form of inevitable impurities are strictly controlled, there is no coarse Al2O3 inclusion, and the non-metallic inclusions are spherical or spheroidal and small in size; the preparation method comprises raw material pretreatment, electric arc furnace smelting, AOD refining, electroslag remelting, homogenization annealing and hot forging, hot rolling, cold rolling and cryogenic treatment, tempering and post-treatment. The alloy component and the preparation process are optimized, the organization is refined, the inclusion form is improved, the matrix density and dislocation density are improved, the mechanical properties, corrosion resistance and wear resistance of the alloy are far superior to those of the prior art, and the balance between strength, toughness and corrosion resistance is achieved.

The invention relates to the field of forging processes, in particular to a forging method for integrally forming an austenitic stainless steel integral cylinder forge piece. The method comprises the steps that a forging material is obtained, and the procedures of electric arc furnace smelting, external refining and electroslag remelting are sequentially adopted; electroslag remelting is used as a key process, chemical components of a steel ingot are controlled, and values are controlled in the optimized chemical components; designing and manufacturing a mold; forging the forging material on a 5000-ton press machine; carrying out solid solution heat treatment according to technical requirements, and cooling in a water cooling manner; sampling the product, and carrying out performance detection on the sample; special regulations are formulated, and nondestructive testing is conducted on the forge piece; the forge piece is precisely machined through special machining equipment, and it is ensured that the product size meets the drawing requirement; the forging allowance can be reduced, the forging precision is improved, the machining amount of forgings is reduced, the research and development period is shortened, the production efficiency is improved, and the production cost of enterprises is greatly reduced.

The invention belongs to the technical field of alloy heat treatment, and particularly relates to a cobalt-based high-temperature alloy pipe, a preparation method and a high-temperature component. The invention discloses a preparation method of a cobalt-based high-temperature alloy pipe. The cobalt-based high-temperature alloy pipe comprises the following components in percentage by weight: 0.05%-0.15% of C, 0.2%-0.5% of Si, less than or equal to 1.50% of Mn, less than or equal to 0.020% of P, less than or equal to 0.010% of S, 20.0%-24.0% of Cr, 20.0%-24.0% of Ni, 13.0%-16.0% of W, less than or equal to 3.0% of Fe, 0.02%-0.12% of La and the balance of Co and inevitable impurities. And then ingot casting, electroslag remelting, forging cogging, hot extrusion cogging, intermediate pipe cold machining, intermediate pipe solid solution heat treatment, finished product cold machining, finished product solid solution heat treatment and finishing are conducted, and finally the cobalt-based high-temperature alloy pipe is obtained.

The application relates to a forming method of high-strength and high-toughness duplex stainless steel seamless pipes, and steps of the method comprise the following: (1) blank preparation: arc furnace+AOD furnace refining+LF furnace refining+electroslag remelting smelting out of a cylindrical electroslag ingot; (2) electroslag ingot rough machining; (3) electroslag ingot heat treatment; (4) electroslag ingot finish machining; (5) hot expanding, expanding with a 2500-ton vertical expander; (6) hot extrusion: extruding the steel pipe with a 6300-ton horizontal extruder; (7) steel pipe heat treatment: heating to 1070 DEG C to 1120 DEG C, and water cooling to below 40 DEG C; (8) straightening and cutting; (9) pickling; (10) steel pipe grinding; (11) cold working: total reducing amount of the steel pipe is 15mm to 30mm; (12) finishing treatment: oil removal-inspection-spray mark-bundling. The duplex stainless steel seamless pipe is produced by combining the optimized composition, the electroslag ingot, the hot expanding, the hot extrusion and the cold working, the purity of the steel, the metal yield and the production efficiency are improved, and the product has high strength, high toughness and good corrosion resistance.

This invention discloses a method for reducing the arsenic and tin content in nickel-based alloy materials. Specifically, in the electroslag remelting process during the preparation of nickel-based alloy materials, a pre-melted slag with the following composition is used: CaF2: 38%–45%, CaO: 20%–25%, Al2O3: 20%–30%, ZrO2: 3%–5%, BaF2: 3%–5%, MgO: 1%–3%, SiO2: 1%–3%, with the remainder being unavoidable impurities; the CaO / Al2O3 ratio in the pre-melted slag is 0.8–1; the pre-melted slag also contains 1–1.5% calcium carbide powder in total slag. Using this method, the arsenic and tin removal rate in nickel-based alloy materials can reach over 46%, effectively solving the problem of difficult arsenic and tin removal in nickel-based alloys. This avoids the impact of As and Sn accumulation on product quality during recycling, creating conditions for the reuse of nickel-based alloy recycled materials.

The invention discloses an electroslag crystallizer sealing structure and a sealing method, and belongs to the technical field of electroslag remelting. Aiming at the problems of secondary oxidation of molten steel, content fluctuation of easily-burnt elements and reduction of purity caused by poor sealing of the bottom of the existing electroslag crystallizer and a dummy ingot plate, an annular groove is formed in the bottom of the electroslag crystallizer and filled with a high-temperature-resistant high-temperature rubber sealing ring with a circular section, so that the annular groove and the dummy ingot plate are extruded to form a sealing structure. The sealing method comprises the stages of preparation, installation, electroslag remelting and disassembly, and the sealing ring can be repeatedly used. According to the structure, the air tightness is remarkably improved, the oxygen content of the tail of the electroslag ingot is reduced, oxide inclusion is reduced, burning loss of elements such as Al and Ti prone to burning loss is reduced, the one-time inspection qualification rate of the elements such as Al and Ti prone to burning loss at the tail of the electroslag ingot is increased, and a low-cost solution is provided for high-quality production of the electroslag ingot.

The application relates to the technical field of metal smelting, in particular to a method for controlling the uniformity of manganese elements in Mn18Cr18N steel and Mn18Cr18N steel with uniformly distributed manganese elements, the method comprises the following steps: adopting an electroslag remelting method to electroslag remelt an electrode rod to obtain an electroslag ingot, and preparing the Mn18Cr18N steel; the electrode rod contains the following elements in percentage by mass: C: 0.05% to 0.1%, Mn: 18.0% to 18.5%, Si: 0.3% to 0.5%, P: less than or equal to 0.03%, S: less than or equal to 0.02%, Cr: 18.0% to 20.0%, N: more than or equal to 0.6%, and the rest is Fe; a cored wire containing metallic manganese is uniformly distributed on the electrode rod, the mass of the metallic manganese is 90 g / m to 200 g / m, one end of the cored wire is flush with one end of the electrode rod, and the other end is 100 mm to 200 mm lower than the other end of the electrode rod.

The application discloses a high-nitrogen plastic mold steel, which comprises the following components: C with a mass percentage of 0.28-0.33%, Si with a mass percentage of 0.25-0.38%, Mn with a mass percentage of 0.4-0.8%, Cr with a mass percentage of 14.5-15.5%, Mo with a mass percentage of 0.9-1%, N with a mass percentage of 0.095-0.115%, P with a mass percentage of less than or equal to 0.02%, S with a mass percentage of less than or equal to 0.003%, and O with a mass percentage of less than or equal to 0.0025%. The method for protecting atmosphere electroslag remelting the high-nitrogen plastic mold steel can ensure the nitrogen content of the plastic mold steel and improve the comprehensive characteristics of the plastic mold steel, for example, the setting parameters of the slag system and the filling ratio can ensure that the crystallized steel ingot is dense, the material is uniform, and non-metallic inclusions can be removed well; the N charging flow rate in the remelting process can keep the balance between the furnace atmosphere and the N content in the molten steel, and can ensure that the N content deviation of the whole steel ingot is small and consistent with the parent material before remelting.

The present application relates to the technical field of corrosion-resistant rack steel plate, in particular to a high-performance corrosion-resistant rack steel plate and a manufacturing method thereof. The high-performance corrosion-resistant rack steel plate is composed of the following chemical components by weight percentage: C: 0.1%~0.15%, Si: 0.22%~0.45%, Mn: 1.1%~1.7%, P≤0.02%, S≤0.01%, Als: 0.03%~0.06%, Ni: 3.8%~5.5%, Cr: 0.7%~1.2%, Mo: 0.5%~0.9%, Cu: 0.25%~0.55%, Sn: 0.05%~0.15%, V: 0.05%~0.09%, Ti: 0.008%~0.02%, N: 0.004%~0.011%, and the rest is Fe and inevitable impurities. The high-performance corrosion-resistant rack steel plate with large thickness is produced by combining high cleanliness and special alloy smelting + casting machine light pressing down + electroslag remelting + forging breakdown + high-efficiency rolling + twice quenching + tempering process. The maximum thickness of the steel plate finished product is 210mm, the yield strength is greater than or equal to 690MPa, the tensile strength is 800~940MPa, the elongation is greater than or equal to 18%, the Charpy impact energy of the core of the steel plate at-40℃ is greater than or equal to 150J, and the corrosion resistance in the marine environment is excellent.

This invention belongs to the field of high-temperature alloy smelting technology and relates to a method for preparing large-size GH4169 alloy electroslag remelting ingots. The method includes the following steps: first, raw materials corresponding to Ni, Fe, Nb, Cr, Mo, and C are mixed to obtain a first mixture; then, raw materials corresponding to Al, Ti, B, and P are mixed to obtain a second mixture; the first mixture is subjected to a first melting and refining process, followed by cooling and the addition of the second mixture for a second melting and refining process, and then cast to obtain an electroslag electrode. The surface of each electroslag electrode is polished, and then electroslag remelting is performed under a protective atmosphere using a five-element slag system. After cooling, a large-size GH4169 alloy electroslag remelting ingot is obtained. This invention effectively improves the compositional uniformity of large-size GH4169 alloy electroslag remelting ingots and increases the ingot yield by optimizing the slag system component ratio and matching the corresponding electroslag remelting process parameters.

The invention relates to the technical field of nuts, and provides a preparation process of a high-strength locknut, which comprises the following steps: taking raw materials, smelting alloy steel by adopting a vacuum induction melting and electroslag remelting process, carrying out solution treatment on the obtained bar, then carrying out hot continuous rolling, controlling the finish rolling temperature at 900 + / -50 DEG C, and rapidly water-cooling to room temperature; carrying out spheroidizing annealing and cold heading forming processing on the wire rod to obtain a nut semi-finished product; the nut semi-finished product is subjected to subcritical quenching treatment; preheating the nut semi-finished product, tempering at low temperature, and preserving heat for 2-3 hours; and the nut is subjected to oil removal, acid pickling activation and hot galvanizing, and finally, the nut is cured for 20-30 min at the temperature of 180-200 DEG C, and then the nut is obtained. According to the high-strength locknut provided by the invention, the balance of high strength, good toughness and wear resistance of the nut is realized.

The invention belongs to the technical field of metallurgy, and discloses an electroslag remelting slag system and an electroslag remelting method for Cr13 type corrosion-resistant die steel, the electroslag remelting slag system comprises the following chemical components: 4-6% of BaO, 4-5% of Ce2O3, 2-2.5% of La2O3, 2-2.5% of Y2O3, 20-25% of Al2O3, more than or equal to 0.7 and less than or equal to 1 of CaO, 2-3% of MgO and the balance of CaF2; the electroslag remelting method comprises the following steps: baking the electroslag remelting slag system, charging, supplying power to carry out arc striking and slag melting, melting after the slag is cleared, carrying out argon protection in the whole smelting process, adding Si-Ca powder as a deoxidizing agent in the electroslag remelting process, feeding by adopting a three-stage feeding process, and carrying out mold cooling and demolding on an electroslag remelting steel ingot prepared by smelting. The Cr13 type corrosion-resistant die steel prepared through the method is high in internal purity, and shrinkage cavities are shallow and flat.

The invention provides application of homogenization heat treatment in reducing or preventing generation of fine cracks and / or cracking in the rolling process of B-containing stainless steel. The temperature of the homogenization heat treatment is 1180 to 1200 DEG C; and the mass content of B in the B-containing stainless steel is 0.010%-0.040%. The invention provides the corresponding preparation method of the B-containing stainless steel, aiming at heat-resistant steel in which more BN inclusions are formed in the electroslag remelting process, through homogenization heat treatment before rolling, a BN precipitated phase is molten back, so that the BN content in a steel billet is reduced, the risk that the steel generates fine cracks or cracks in the subsequent rolling process is prevented, and the quality of the steel is improved. Therefore, the flaw detection qualification rate of the steel billet and the comprehensive mechanical property of the steel billet subjected to quenching and tempering heat treatment are improved.

The application relates to a low-resistivity expansion alloy material and a preparation method thereof, and belongs to the technical field of expansion alloy materials. The low-resistivity expansion alloy material comprises the following chemical components in percentage by weight: Ni: 51-51.5%, C<=0.005%, S<=0.005%, P<=0.005%, Si<=0.005%, Cu<=0.005%, Mo<=0.03%, Al<=0.005%, Cr<=0.05%, Mn<=0.1%, Ti<=0.005%, and the balance of Fe and inevitable impurities. In the application, the refining is carried out through a triple method: electric furnace smelting, electroslag remelting and vacuum consumable smelting, impurities are removed step by step, purity is gradually increased, and through subsequent heat treatment processes, the organization is refined and defects are controlled, the influence of alloy elements and impurities on the resistivity is reduced, and thus the performance requirements are met.

The invention relates to the technical field of ultrahigh-strength steel materials, and particularly discloses a preparation method of an ultrahigh-strength SF1900 steel vacuum consumable steel ingot. The preparation method of the ultrahigh-strength SF1900 steel vacuum consumable steel ingot comprises the steps of vacuum induction melting, protective atmosphere electroslag remelting and vacuum consumable remelting. According to the production method, the vacuum induction furnace, protective atmosphere electroslag and vacuum consumable electrode furnace triple smelting technology is adopted for production, comprehensive optimization of purity, inclusion control, component uniformity and solidification structures is achieved, and the consistency of the solidification structures, macrosegregation and chemical component uniformity of the steel ingots is improved.

The invention discloses a preparation method of an ultra-fine grain nickel-based alloy and a product of the ultra-fine grain nickel-based alloy. The method comprises the following steps: step 1, preparing a required electroslag ingot by adopting a vacuum induction and electroslag remelting smelting method; 2, the electroslag ingot obtained in the step 1 is subjected to high-temperature homogenization diffusion annealing; 3, a high-speed forging machine is adopted, and the homogenized electroslag ingot is forged into an intermediate billet with the required specification at the temperature of 1100 DEG C through multiple heating numbers; 4, intermediate heat treatment is conducted on the intermediate blank in the step 3; and 5, the intermediate billet subjected to intermediate heat treatment in the step 4 is subjected to low-temperature multi-heating-number forging.

The invention discloses large ingot type cold work die steel and a preparation process thereof. The die steel comprises the following components in percentage by weight: 0.69%-0.75% of C, less than or equal to 0.50% of Mn, 0.70%-0.90% of Si, less than or equal to 0.01% of S, less than or equal to 0.030% of P, 6.90%-7.10% of Cr, 1.90%-2.00% of Mo, 1.80%-2.00% of V, less than or equal to 0.02% of Al and the balance of iron. The preparation process comprises the steps of non-vacuum induction furnace smelting, LF furnace refining, VD furnace vacuum treatment, electrode bar pouring, electroslag remelting, multi-stage heating forging and annealing. The smelting and forging processes are optimized. The method has the advantages that the problems of serious carbide segregation and low internal crack flaw detection percent of pass of the large ingot type high-carbon die steel are effectively solved, and finally a large module of 4.5 t grade or above, which is uniform in structure, high in obdurability and excellent in wear resistance, is obtained.

The invention discloses a wear-resistant steel-based mold material for plastic magnetic injection molding and a preparation method of the wear-resistant steel-based mold material, and relates to the technical field of mold steel materials. When the steel-based mold material is prepared, metal chromium, titanium powder, ferromolybdenum, graphite, ferroboron, lanthanum iron and electrolytic iron are weighed according to a specific proportion, and a cast ingot is obtained through vacuum induction melting and argon protection pouring; a calcium fluoride-aluminum oxide-calcium oxide mixed slag system serves as a remelting medium, electroslag remelting, homogenization treatment and oil quenching are conducted on the cast ingot, and a steel ingot is obtained; the steel ingot is subjected to multidirectional forging and temperature-controlled cooling, and forged die steel is obtained; and finally, the forging die steel is subjected to gas nitriding subzero treatment and multi-stage tempering, gradient titanium nitride and chromium nitride metal ceramic layers are induced to be formed on the surface, and the wear-resistant steel-based die material for plastic magnetic injection molding is prepared. The prepared steel-based mold material has high hardness, high wear resistance and corrosion resistance.