10results about How to "Refined grain size" patented technology

This invention relates to a forging method for improving the grain size of austenitic stainless steel pipes with nozzles. The method involves taking an electroslag ingot with a diameter of Φ1000–1200 mm, holding it at 1180±10℃ for 9–12 hours, and then drawing it to form a billet. After returning the billet to the furnace, the temperature is raised to 1200±10℃ and held for 7–8 hours. The billet is then upset with a flat upsetting cap, drawn into a flat square shape, and marked to form a flat square billet. This flat square billet is held at 1180±10℃ for 3–4 hours, drawn to lengthen both ends, and staggered to form a billet with a staggered nozzle. This staggered nozzle billet is held at 1150–1180±10℃ for 3–4 hours and then drawn, completing the forging process in one firing. This four-firing forging method for pipes with nozzles achieves a grain size ≥4 in the forging body, significantly improving the overall grain size of the austenitic stainless steel pipe with nozzle.

The invention relates to a preparation method of high-purity and high-toughness hot work die steel, which comprises the following steps: S1, electric furnace smelting; s2, refining in a ladle refining furnace; s3, refining in a vacuum refining furnace; s4, performing die casting on an electrode blank; s5, annealing the electrode blank; 6, electroslag remelting is conducted, specifically, an electrode blank is adopted, surface polishing is conducted, a calcium fluoride, aluminum oxide, magnesium oxide and silicon dioxide quaternary slag system is adopted for smelting, the starting point melting speed value of the electroslag smelting steady-state stage is 7-10 kg / min, the end point melting speed value of the electroslag smelting steady-state stage is 5.0-8.0 kg / min, an electroslag ingot is obtained, and then power-off furnace cooling is conducted for 80-100 min; s7, forging is conducted; s8, pretreatment after forging; and S9, solid solution and spheroidizing final treatment. According to the invention, on the basis of common hot work die steel H13, the prepared product has excellent high hardness, high purity and high toughness through fine adjustment of chemical components and special smelting, forging and heat treatment processes. The anti-cracking performance of a mold made of the material is greatly improved, the service life of the mold is prolonged, and meanwhile the use cost of the mold is greatly reduced.

The present application relates to the technical field of highway-railway dual-purpose transport equipment, in particular to a highway-railway dual-purpose steel rail double-frequency electric normalizing train, which comprises a vehicle body, a tool container and a mobile steel rail pressure-keeping double-frequency electric normalizing device are carried on the vehicle body; the vehicle body comprises a truck chassis assembly, a load-bearing frame and a hydraulic pump station are connected to the truck chassis assembly, and a set of telescopic hydraulic leg mechanisms are arranged at the front and rear ends of the truck chassis assembly respectively, and a wheel-rail running lifting mechanism is connected to the load-bearing frame; the present device is suitable for post-welding pressure-keeping double-frequency electric normalizing heat treatment operation of steel rail joints in seamless lines and urban rail transit. Furthermore, the device and the tool box are integrated and installed on a highway-railway dual-purpose vehicle, so that the working efficiency is improved, the on-and-off track operation and construction requirements of the device are facilitated, and the hoisting and carrying cost of the device can be greatly saved.

The present application relates to the technical field of titanium-based cathode roller, in particular to a large-size titanium-based cathode roller and a processing technology thereof, comprising the following processes: step one, taking a blank to carry out high-temperature blooming upsetting, punching, hole expanding, mandrel drawing, and obtaining a ring blank; step two, taking the ring blank obtained in step one to perform dressing and marking inspection; step three, taking the ring blank obtained in step two to perform turning, and obtaining a ring piece; step four, taking the ring piece obtained in step three to perform post-processing, and obtaining a cathode roller. The present application uses a new technology of forging-rolling combination to successfully produce a whole seamless ring piece at one time, which can effectively meet the requirements of the cathode roller on the morphology and mechanical properties at the microstructure level, and eliminate the occurrence of periodic bright band during the production of copper foil by the customer.

The application relates to the field of steel cords, in particular to a high-strength steel cord which comprises, in percentage by mass, 0.80-0.96% of carbon, 0.25-0.45% of manganese, 0.05-0.12% of vanadium, 0.15-0.3% of silicon, 0.08-0.15% of molybdenum, 0.02-0.05% of niobium, 0-0.08% of copper, 0-0.005% of aluminum, 0.15-0.3% of chromium, 0-0.06% of nickel, and the rest is iron; molybdenum and niobium are added in the steel cord to reduce the brittleness of the steel cord, reduce the wire breakage rate in the preparation process of the steel cord, and the carbon and vanadium contents are further improved, so that the strength of the steel cord is further improved, the high strength of the steel cord is ensured, and the excessively high wire breakage rate in the preparation process of the steel cord is prevented.

The application discloses a titanium alloy special-shaped material production process for a mobile phone physical SIM card holder, and comprises the following steps: continuously hot-rolling titanium alloy wire rods to deform to corresponding sizes; performing acid pickling at least once before the last hot-rolling to remove the surface oxides of the wire rods; performing annealing treatment at least once after the last hot-rolling; performing cold-rolling and shape correction after the annealing to make the cross-sectional size of the product meet the final product size; performing annealing treatment at least once after the cold-rolling; performing acid pickling at least once after the cold-rolling and annealing treatment to remove the surface oxides of the wire rods; cutting after online straightening to form the final special-shaped material for the SIM card holder; and the multiple rolling and heat treatment mode solves the problem of difficult machining and forming of the titanium alloy, the shape of the wire rod is shaped through cold-rolling, the titanium alloy wire rod is shaped, and the mobile phone SIM card holder special-shaped material is formed through rolling.

The application discloses a heat treatment process of low-alloy steel castings, and the heat treatment process of the low-alloy steel castings controls the chemical element content of the low-alloy steel castings reasonably, so that the strength of the steel castings is higher; the heating temperature in the heat treatment process is appropriately increased, and the holding time is prolonged, so that the structure transformation of the steel is sufficient, and the mechanical performance and the impact toughness are effectively improved. The heat treatment process adopts a process flow of preheating + normalizing + tempering + quenching + annealing, and compared with a traditional heat treatment process, the heat treatment process has the advantages that the grains are further refined and uniform, the grain size is maximally increased, and good structure conditions are prepared for subsequent heat treatment.

This invention relates to a forging method for stepped gear shafts from continuously cast billets with diameters of φ600~φ785mm. The method involves loading the continuously cast billet into a heating furnace, holding it at 700~800℃, and then raising it to 1230℃±10℃. The billet is then upset with the tail end facing upwards using a concave upsetting plate, with an upsetting height-to-diameter ratio of 0.6~0.7. The billet is then drawn on an upper and lower flat plate, with a reduction of 13~18% per pass, and rotated 90° per pass. Finally, the billet is drawn on upper and lower flat anvils, with a reduction of 18~22%, and fed into the anvils at full capacity, ensuring at least one [unclear unit] per two anvils. With a 5% anvil loading, the anvil is rotated 90° per pass. A 3150-ton hydraulic press is used to upset the riser end with a concave upsetting plate, resulting in a height-to-diameter ratio of 0.6 to 0.8. The billet is drawn to be 20 to 30 mm larger than the maximum step diameter of the stepped gear shaft. After scoring, the billet is kept at a furnace temperature of 1030±10℃. The small steps at both ends are forged into finished products, and the large steps are forged into finished products within the range of 760℃ to 790℃. This improves the actual grain size and banded structure qualification rate of the stepped gear shaft, reduces the need for one normalizing step, and improves the low-magnification structure.

The present application relates to a kind of high-chromium high-nickel nitrogen-containing stainless steel forging billet quality control method, which can not only reduce forging heating fire times and save production cost, but also effectively improve the overall quality of the forging billet, suitable for the forging billet with outer diameter ≤350mm, first manufacturing intermediate billet with certain forging ratio + intermediate billet normalizing + air cooling + hydrogen annealing + forging billet surface temperature control + limited speed heating and step temperature holding + normalizing + temperature control cooling to promote microstructure transformation + high-temperature tempering and isothermal transformation composite process, which not only reduces forging heating fire times, saves production cost, but also effectively improves the overall quality of the forging billet.

The invention relates to the field of metal materials, in particular to a niobium-containing 304 austenitic stainless steel plate for nuclear power and a preparation method of the niobium-containing 304 austenitic stainless steel plate for nuclear power, and the niobium-containing 304 austenitic stainless steel plate comprises the following components in percentage by mass: 0.02%-0.06% of C, 1.00%-2.00% of Mn, 0.20%-0.75% of Si, 0-0.030% of P, 0-0.005% of S, 18.00%-19.50% of Cr, 8.00%-10.50% of Ni, 0.2%-0.8% of Nb, 0-0.10% of Cu, 0-0.10% of Co, 0-0.10% of N and the balance of Fe and other inevitable impurities. The 304 austenitic stainless steel is improved, and the niobium element is added, so that stable production of the 304 austenitic stainless steel plate for nuclear power can be ensured, the 304 austenitic stainless steel plate has excellent grain size, intergranular corrosion resistance and mechanical property, and the design requirements of steel for nuclear power are met.