52results about How to "Improve coagulation tissue" patented technology

The present invention provides a continuous casting method capable of increasing non-oriented silicon steel medium-thickness continuous cast slab equiaxial crystal rate. It is characterized by that it adopts a medium-thickness slab continuous casting machine, in the continuous casting second cooling zone it adopts a roller electromagnetic stirring equipment. The casting billet size of continuous casting machine is 100-150mmX850-1550mm, pouring speed is 1.5-3.5m/min, the cooling pattern: the narrow edge of crystallizer is 14-25m3/h, the wide edge of crystallizer is 250-290m3/h and second cooling intensity is 1.3-1.8L/kg. The described electromagnetic stirring equipment includes 2-4 pairs of introroller built-in traveling wave magnetic field type electromagnetic stirring devices which are assembled into two groups and mounted.

The invention relates to hot-working die steel and an efficient preparation method thereof. The hot-working die steel comprises, by weight, 0.34%-0.45% of C, 1.00%-1.40% of Si, 0.50%-0.60% of Mn, lessthan or equal to 0.015% of P, less than or equal to 0.015% of S, 5.00%-6.00% of Cr, 1.00%-1.20% of Mo, 0.08%-0.12% of Nb, 1.00%-1.30% of Ni, and the balance Fe and inevitable impurities. The preparation method has the advantages that the alloy components are optimized, and mechanical diffusion and thermal diffusion are adopted to jointly act, so that the components of the hot-working die steel are homogenized, the time required for homogenization of the alloy elements is shortened, the production efficiency is improved, the production cost is reduced, the produced hot-working die has the Rockwell hardness of 55-57 HRC, the isotropic performance is good, and the thermal stability is good.

The invention discloses a continuous casting production control method for a super-large section heavy rail steel, and particularly relates to the continuous casting production control method in the field of ferrous metallurgy for the super-large section heavy rail steel. According to the continuous casting production control method for the large-section heavy rail steel, a parabolic taper curve type tubular mold is adopted, a cooling water pipeline is provided with two cooling water inlets and two cooling water outlets, a super-large section heavy rail steel mold adopts an immersion type water port, a double-side hole mode is adopted in the immersion type water port, the intensity of stirring currents ranges from 300-400A, the current frequency is 2.4Hz, the specific water flow of secondary cooling water is matched with the pulling rate at mold subsequent solidification section, and the solidification tail end is pressed down. According to the method, molten steel flow fields and solidification cooling of the mold are effectively controlled, a secondary cooling system is reasonably controlled on the basis, a force field is externally applied to a casting blank, the casting blank solidification structure is optimized, the segregation of solute elements is improved, and the compactness of the center of the casting blank is improved.

A process for preparing the Al-base composition under strong magnetic field includes such steps as heating Al to 850 deg.C, holding the temp for 30 min, adding reinforcing Al2O3 particles (or short fibres), stirring, pouring in mould, solidifying for 20 min strong magnetic field system and cooling in air. Its equipment is composed of metallic ladle, heating system, thermoelectric couple, reinforcing material delivering pipe, stirring coil, casting mould, supporter, slide sprue, vacuum chamber or protecting gas chamber, and the strong magnetic field control system consisting of strong magnetic field genrator, cooling water pipe, alarm and temp control unit and insulating layer.

The invention relates to a method for direct interfering casting blank quality, belonging to field of continuous cast steel production technology. The method employs feeding apparatus to insert metallic band into mould liquid steel, and said band can vibrate according to applicable frequency and amplitude. The method interferes internal coagulation and crystallization directly by controlling band inserting mode and speed, the degree of superheat of crystallizer liquid steel is reduced, depth of liquid core is shortened, columnar crystal is decreased, equiax crystal proportion is increased, coagulation tissue of cast blank is improved, central aliquation is released, zigzag plasticity, dynamic ductility of steel products are improved, and fault localization percent of pass is increased. Furthermore, the pulling rate and production rate can be increased on condition of guaranteeing cast blank quality. The invention is characterized by low investment, reduced energy consumption, low operation cost, convenient device maintenance, and eligibility for various cast blank production.

The invention discloses a method of manufacturing a clad layer on the basis of a vibration-assistant ultrahigh-speed laser cladding technology. The method specifically comprises the steps that a workpiece is fixed to a workbench, the surface of the workpiece is cleaned, ultrahigh-speed laser cladding powder is preheated, screened and then fed into a powder feeder, a laser spot and a powder focusing spot are adjusted to be located on the same straight line, coaxial powder feeding is adopted, powder feeding is adjusted, and then an ultrasonic high-frequency impact head is adjusted to make contact with the workpiece; and an ultrasonic high-frequency impact facility is started, an ultrahigh-speed laser cladding facility is started to conduct cladding operation on the workpiece, the impact headcan conduct violent reciprocating vibration through the high frequency of the ultrasonic high-frequency impact facility, and the purpose that the impact is immediately conducted on a coating which isjust subjected to the cladding operation can be achieved. The vibration is applied to the clad layer in the ultrahigh-speed laser cladding process, and therefore the effects that the residual stressof the clad layer is reduced, the crystal grain is refined, and the organization is uniform can be achieved, the crack sensitivity of the clad layer can be reduced, the metal solidification structurecan be improved, and the mechanical property can be improved.

The invention discloses an electroslag remelting method for Hastelloy, wherein an adopted consumable electrode is subjected to high-temperature diffusion annealing at 1100-1150 DEG C, after which theelectroslag remelting is performed under the protection of argon; and the smelting rate during the electroslag remelting is 3 kg/min-3.5 kg/min. According to the electroslag remelting method, the adopted consumable electrode is subjected to high-temperature diffusion annealing firstly, the electroslag remelting is performed after homogenization is finished, low smelting speed control is adopted, and thus a uniform solidification structure of a cast ingot can be effectively guaranteed, and a Hastelloy steel ingot with uniform and excellent component structure is obtained. According to the electroslag remelting method, the matching of an electroslag slag system is guaranteed, the liquidus temperature of Hastelloy is relatively low, a shallow and flat molten pool can be obtained by adopting higher voltage and lower current in the smelting period, and therefore good surface quality can be guaranteed at a low smelting speed; and by properly increasing the filling ratio, the electroslag process is improved, the direct current component of the crystallizer in the electroslag process is increased, the lower slag temperature and the smaller molten pool volume are kept, the width of a two-phase region is reduced, the local solidification time is shortened, and a better solidification structure is obtained.

Provided is a method for improving internal quality of casting blank by composite intervention. The method comprises following steps: 1), machining pure iron or steel with the approximate content of steel grades to be an easily-melted cold bodies moving with molten steel and then drying; 2), baking feeding guide pipes which are made by refractory material and immersing them into a crystallizer below the molten steel surface; aligning feeding guide pipe openings to the center of steel streams as for round and square billets; utilizing two guide pipes for plate blank and distributing them on two sides of a wide surface of the crystallizer; 3), continuously injecting the dried cold bodies into a high-temperature region of a molten pool of the crystallizer, adding the cold bodies in the amount of 0.8-1.3% of casting blank; adopting the crystallizer to electromagnetically stir during the continuous casting process. The method for improving internal quality of casting blank by composite intervention has following beneficial effects: cold bodies are fed into the crystallizer such that superheat and temperature gradient of molten steel during mass production of continuous casting; the solidification structure of casting blank is improved; quality flaws of the internal quality of the casting blank is reduced; the temperature field of the crystallizer is improved; and therefore the purposes of increasing equiaxial crystal ratio and improving internal quality of the casting blank are fulfilled.

The invention provides an austenitic stainless steel containing a rare-earth element, which comprises the chemical components in weight percent: not greater than 0.06 percent of carbon (C), 17.0-19.0 percent of chromium (Cr), 0.5-0.7 percent of manganese (Mn), 8.5-10.5 percent of nickel (Ni), 0.04-0.06 percent of rare-earth element, not greater than 1 percent of silicon (Si), not greater than 0.02 percent of phosphorus (P), not greater than 0.02 percent of sulfur (S) and the balance of ferrum (Fe). The austenitic stainless steel containing the rare-earth element has fewer elements, simple components and the conventional performance of common austenitic stainless steel. Moreover, columnar crystals and equiaxed crystals can be obviously refined by the addition of mischmetal, and the sheet moldability of the austenitic stainless steel is improved. Moreover, the impact performance of the austenitic stainless steel is also greatly improved, and the high-temperature oxidation resistance is also improved to a certain extent.

The invention relates to high-Cr-content cast heading machine cutter steel. The cutter steel comprises the chemical components of, by weight, 0.30%-0.55% of C, 8.0%-12.0% of Cr, 1.2%-3.0% of Mo, 0.5%-1.8% of Ni, 0.6%-1.0% of V, 0.1%-0.4% of Mn, 0.6%-0.8% of Si, 0.04%-0.30% of N, no more than 0.005% of S, no more than 0.03% of P and the balance Fe. The cutter steel manufacturing technique comprisesthe following steps that a near-net shape blank of a cutter is obtained through precise casting, then heat treatment is conducted, and a finished product is obtained directly after fine machining. Yield strength and tensile strength are improved while the hardness, impact toughness and elongation of the cutter steel all can reach the level of domestic forged heading machine cutter steel; the oxidation corrosion resistant capability, thermal fatigue resistant performance and abrasive grain abrasion resistance are improved; and the production period is shortened, and the production cost is reduced.

The invention discloses a preparation method of ultra-pure G102Cr18Mo stainless bearing steel, and belongs to the technical field of metal smelting. According to the method, firstly, base metal needed for preparing the ultra-pure G102Cr18Mo stainless bearing steel is obtained through intermediate frequency furnace smelting, LF furnace refining, sedation treatment and die casting, the oxygen content ranges from 20 ppm to 30 ppm, and conditions are created for ultra-pure stainless steel bearing steel smelting; then, the base metal is subjected to forging and scaling treatment and then is put into a vacuum induction furnace to be melted and refined, and no alloy element is added in the vacuum induction treatment process; a consumable electrode subjected to vacuum induction melting is subjected to vacuum consumable remelting twice, and the G102Cr18Mo stainless bearing steel with extremely high purity can be obtained.