14 results about "Holding time" patented technology

The present application relates to a kind of thin mechanical hard disk with aluminium round sheet, the aluminium round sheet thickness is 0.5~0.8mm, diameter is 95.0~98.2mm, surface flatness is less than 5 μm;The present application also relates to a kind of flatness control method of thin mechanical hard disk with aluminium round sheet, including the following steps: aluminium coiled material striping, stamping blanking, flattening and primary annealing treatment, rough grinding treatment, secondary annealing treatment, fine grinding treatment;Wherein aluminium round sheet is flattened and primary annealing treatment when pressure is 120‑200Kg, annealing heating rate is 80℃ / h~200℃ / h, cooling rate is 30℃ / h~70℃ / h after annealing ends, annealing holding temperature is 320°C~360°C, holding time is 2h~5h.The flatness value of aluminium round sheet of the present application is not higher than 5 μm, can guarantee the stable performance of mechanical hard disk, reduce the influence of mechanical hard disk disc in work, guarantee the stable flatness of aluminium round sheet, flatness has no rebound phenomenon, and the processing yield is high.

The invention relates to the technical field of low-pressure casting, and discloses a low-pressure casting method for feeding in a pressurization mode. The operation process of the method comprises the steps that after a molten metal mold is filled, a pressure control system is switched to a closed-loop mode based on real-time solidification feedback; the basic feeding pressure P1 of 0.02-0.04 MPa is applied, so that a closed shell layer is formed on the surface layer of the casting; within 3-8 seconds after the surface layer is solidified, linearly increasing the pressure from P1 to P2 which is 1.8-2.2 times of the pressure within 2-4 seconds; with P2 as a reference, sine fluctuation feeding is carried out for 10-20 seconds at the frequency of 0.5-2 Hz and the amplitude of 0.05 P2 to 0.15 P2; and finally, the pressure is relieved to atmospheric pressure in three to five stages, and the retention time between the stages is not less than 2 seconds. According to the method, precise feeding is achieved through multi-stage time sequence pressure regulation and control, and the solidification quality of the casting is improved.

Method for heating a component (1) in a continuous furnace (2), comprising a) Moving the component (1) from a furnace inlet (3) into a holding zone (5) of the continuous furnace (2), b) Stopping the component (1) in the stopping zone of the continuous furnace (2) for a stopping time, c) after the holding time, move the component (1) to a furnace outlet (7), wherein the component (1) passes through an oven zone (4) upstream of the stopping zone (5) in step a) and is subsequently moved through an opening (10) in an upstream boundary (8), wherein the opening (10) is reduced in size at least during part of the stopping time, and / or wherein the component (1) is moved through an opening (10) in a downstream boundary (9) in step c) and subsequently passes through an oven zone (6) downstream of the stopping zone (5), wherein the opening (10) is reduced in size at least during part of the stopping time according to step b).

The invention discloses a process method for regulating and controlling BTWJ-XN yield strength of carbon structural steel, which is characterized by comprising the following steps of: 1) hot rolling process: raising the coiling temperature from original 650 DEG C to 665 DEG C, and controlling the fluctuation range of the coiling temperature to be 664-712 DEG C; in the production process, it is ensured that the proportion of steel coils with the coiling temperature hit rate exceeding 97% is not lower than 68%, and the proportion of steel coils with the coiling temperature hit rate being 90%-96% is not lower than 18%, so that the stability of the coiling temperature is ensured; (2) a continuous annealing process: the temperature of a heating section and a soaking section is increased to 755 DEG C from original 740 DEG C, and the heat preservation time is controlled within 3-5 min; and then cooling to room temperature at a cooling speed of 2.2-2.5 DEG C / min. By cooperatively adjusting the hot rolling coiling temperature and the heating soaking temperature of the continuous annealing furnace area, the yield strength is precisely reduced, and it is guaranteed that other mechanical properties of the product stably reach the standard.

The application discloses an alloy material composition, and raw materials for preparing the alloy material composition at least include the following components in percentage by weight: C 0.3-0.6%; Si 0.25-0.55%; Mn 0.05-0.35%; Ni 7-8.5%; Co 2.5-4%; V 0.2-0.6%; P <0.06%; S <0.03%; Cr 2-3.5%; Mo 5-7%; and the balance of Fe and inevitable impurities. The application selects specific metal elements, controls the content, and further limits the temperature and holding time of heat treatment, so that different performances can be obtained, the product with good comprehensive performance can be obtained when the alloy layer or alloy product is prepared, the hardness and toughness are considered, the product has good wear resistance and stable heat conductivity, and the requirements of work such as an aluminum product die casting die can be met.

This application provides a method for finely controlling the high-strength and high-toughness martensite-bainite multiphase microstructure of high-carbon steel bearings, relating to the field of bearing manufacturing technology. The method includes: in response to a fine-control operation of the martensite multiphase microstructure of a target bearing, obtaining process parameters for austenite grain size and austenite carbon content; based on the austenitizing process parameters, calculating the austenitizing holding temperature and austenitizing holding time corresponding to the target bearing meeting preset process conditions; performing austenitizing process treatment on the target bearing according to the austenitizing holding temperature and austenitizing holding time; performing strength and toughness optimization treatment on the target bearing after austenitizing process treatment, and obtaining the martensite-bainite multiphase microstructure corresponding to the target bearing through strength and toughness optimization treatment. This application solves the problem that blindly increasing the isothermal quenching temperature in pursuit of a short incubation period and high nucleation rate easily leads to coarsening and merging of the lath microstructure, thus degrading performance.

The invention relates to a method for hardening a sheet or strip made of an aluminum alloy of the 6xxx row and to a sheet or strip produced using said method. In order to accelerate the hardening method, a multistage thermal treatment is proposed which includes a process of maintaining a second holding temperature (T2) ranging from 150 to 250° C. for a second holding time (h2) and a subsequent second accelerated cooling process, wherein the second holding process together with the subsequent second accelerated cooling process interrupts the first holding process multiple times, thereby dividing the first holding process into holding stages, in each case at a first holding temperature (TI) ranging from 60 to 140° C. and for a first holding time interval (hIa, hIb, hIc, hId, hIe) which lasts longer than the second holding time (h2).

A storage container is provided. The container may be insertable into a cold-storage dewar or other cold-storage container and may have multiple compartments. A payload item may be inserted into a tray and placed in one compartment for cold storage. Temperature buffering material may be inserted into one or more other compartment to provide for increased holding time at or near a desired temperature.

The invention relates to a method for determining the pre-rotation holding time of a wheel disc, belongs to the technical field of metal materials, and solves the problems of long test period and high cost caused by the fact that multiple rounds of tests and verification are needed to determine reasonable holding time in the process of releasing residual stress in the wheel disc through pre-rotation in the prior art. The method comprises the following steps: carrying out tensile load holding tests of different stress levels on a sample, and establishing a corresponding relationship between the load holding plastic strain in the tensile load holding stage and the tensile load holding stress sigma and the load holding time t: epsilon dc (t) = f (sigma, t); the equivalent stress sigma < eff > borne when the wheel disc is loaded to the maximum pre-rotating speed and the outer diameter plastic deformation Dac of the wheel disc in the speed increasing stage are subjected to analog calculation, and target plastic deformation Ddc for carrying out load holding on the wheel disc is determined; and determining the pre-rotation holding time of the wheel disc. The method for determining the pre-rotation load holding time of the wheel disc is simple and rapid, and plastic deformation generated by the wheel disc in the pre-rotation load holding stage can be accurately controlled.

The invention discloses an aluminum alloy plate high-temperature rolling rapid connection method, and belongs to the field of aluminum alloy diffusion connection. The invention aims to solve the problems of low production efficiency and low strength caused by high connection temperature, long heat preservation time, difficulty in breaking an oxide film and high equipment requirement during large-area connection in the existing aluminum alloy connection process. On the basis of a plate hot-rolling composite process, an interlayer foil is added between to-be-connected areas of an aluminum alloy plate, during rolling at the temperature lower than or close to the eutectic temperature of the interlayer material and aluminum, an interface original oxidation film is broken through plastic deformation, the temperature of a connecting interface is increased to reach the reaction temperature, and the interlayer material is rapidly diffused; and efficient metallurgical connection of the aluminum alloy plates is achieved. According to the method, interface vacuum protection can be achieved in the rolling connection process, the problem that materials are violently oxidized in the non-vacuum high-temperature environment is effectively avoided, meanwhile, the equipment requirement is low during large-area connection, and cost can be greatly reduced and efficiency can be greatly improved.

The invention relates to the technical field of ferrous metallurgy, and particularly discloses an HG6EC high-performance bar rolling method which comprises the following steps: S1, temperature control: the tapping and rolling temperature of a steel billet, the temperature control range of a preheating section, a heating section and a soaking section and the heating and heat preservation time; s2, rolling parameter optimization: controlling rolling hole pattern design, loop parameters and in-furnace time control; the size, the appearance, the weight and the allowable deviation of the steel meet the standard requirements, the included angle beta between the transverse ribs and the axis of the steel bar is controlled to be 45-70 degrees, and the directions of the transverse ribs on the two opposite faces of the steel bar are opposite; the angle alpha is not less than 45 degrees; s4, performance requirements including tensile strength, lower yield strength, ductility, impact performance and bending performance control; through reasonable alloy element ratio, heating schedule, heating speed and innovative rolling process, the ductility of the steel bar is ensured, and the steel bar has good plasticity, high-efficiency cost reduction and outstanding energy conservation and emission reduction.

The purpose of this invention is to provide a hot work tool steel with excellent high-temperature strength and toughness, comprising, by mass%, C: 0.20% to 0.60%, Si: 0.10% to 0.30%, Mn: 0.50% to 2.00%, Ni: 0.50% to 2.50%, Cr: 1.6% to 2.6%, Mo: 0.3% to 2.0%, V: 0.05% to 0.80%, and the balance being Fe and unavoidable impurities. This hot work tool steel is designed to achieve the following value A: A = ([T] + 273)(log 10 [t]+24) / 1000…(A) [where [T] represents the quenching temperature (°C), and [t] represents the quenching temperature holding time (h).] The calculated value A is the state of quenching and tempering in the hot work tool steel with a temperature between 27.4 and 29.3 μm before use. 2 The number of carbides with an equivalent circle diameter of 1 μm or more is less than 150.

Method for controlling the temperature of a shrink-fit chuck (10) for tools (16), in which heat energy is supplied to the shrink-fit chuck (10) by means of a heating device (32) with a predetermined time profile in such a way that a tool holding section (12) of the shrink-fit chuck (10) reaches a tool joining dimension after a warm-up opening time elapsed up to an opening time (TO) and remains open for a predetermined holding time (ZH), characterized in that the supply of heat energy is controlled or regulated such that the heat output (Q̇, WL) of the heating device (32) is lower than a maximum initial heat output (WLAM) at a time (T1; T1*;T1**), which is before the opening time (TO) of the shrink chuck (10), is reduced, and the total amount of energy (QV) supplied up to the opening time (TO) of the shrink chuck (10) is chosen to be large enough that the shrink chuck (10) still achieves the tool joining dimension under the influence of the heat energy absorbed and stored by the material of the shrink chuck (10).

The application provides a spiral type roll repair method of a roll of a skew rolling mill, which is used for repairing the used roll, achieving the purpose of roll reuse, reducing roll consumption, improving roll utilization rate and reducing production cost. The repair method comprises the following steps: 1) annealing the worn roll, so that the surface hardness of the roll is reduced to below HRC35; 2) re-machining the spiral hole type of the roll after annealing; 3) after the machining is completed, heat treatment is carried out again, so that the roll with the hardness of the spiral hole type greater than HRC60 and the hardness of the roll body greater than HRC56 is obtained; and 4) after isothermal quenching, low-temperature vacuum tempering at 160-180 DEG C is carried out, and the holding time is 3-6 hours.