13results about "Heat treatment baths" patented technology

In order to subject a metal member to cooling under isothermal heat treatment, a salt-bath heat treatment apparatus 10 comprises: a salt bath tank 1 which accommodates a nitrate salt bath including a molten nitrate salt; a water addition device 2 to add water to the nitrate salt bath in the salt bath tank 1; a humidity detection device 5 comprising a humidity sensor 53a to output a signal corresponding to humidity caused by water vapor generated from the nitrate salt bath with water added by the water addition device 2; and a control device 100 configured to control the water addition device 2 to adjust an addition amount of water to the nitrate salt bath, based on the signal output from the humidity sensor 53a of the humidity detection device 5.

The invention discloses a high-toughness corrosion-resistant pearlite steel wire with an adjustable honeycomb structure characteristic as well as a preparation method and application of the high-toughness corrosion-resistant pearlite steel wire, and belongs to the technical field of pearlite steel wire processing. The surface of the steel wire is provided with an aluminum alloy coating which is metallurgically bonded with a base body and has the thickness of 8-10 microns; the steel wire is subjected to ultrasonic treatment to generate a structure with a honeycomb characteristic, and the obtained cementite lamella serves as a hard phase to form a regular'honeycomb wall ', so that a core supporting effect is achieved; the ferrite serving as a plastic phase is coordinated and deformed under the action of external force by forming a honeycomb unit with uniform size, so that more energy is absorbed and crack propagation is hindered; and an Al2O3 protective film is instantaneously formed on the surface of the aluminum alloy coating, so that the aluminum alloy coating has excellent corrosion resistance and better mechanical properties. The Vickers hardness of the aluminum alloy reaches up to 830-850 HV < 0.1 >, the tensile strength of the aluminum alloy reaches 3100-3200 MPa, and the ductility of the aluminum alloy reaches 16-20%.

This invention provides a high-strength steel with a low yield strength ratio of 1100MPa and its production method. The steel plate has the following chemical composition by mass percentage: C 0.15~0.17%, Si 0.58~0.6%, Mn 2.53~2.6%, Cr 0.53~0.8%, Ni 1.44~1.6%, Mo 0.2~0.6%, Nb 0.052~0.08%, V 0.02~0.08%, Ti 0.019~0.03%, Al 0.01~0.05%, Cu 0.83~1.5%, with the balance being Fe and unavoidable impurities. The steel plate has a yield strength ≥1100MPa, a yield strength ratio ≤0.88, an elongation ≥14%, and an impact energy ≥30J at -40℃. The finished steel plate has a thickness of 15mm and a microstructure of tempered lath martensite. The high-strength steel plate of this invention, with a yield strength ≥1100MPa, yield strength ratio ≤0.88, elongation ≥14%, and impact energy ≥30J at -40℃, exhibits a low yield-to-tensile ratio. The advantage of this invention lies in the fact that the salt bath Q&P heat treatment process achieves a good balance between high strength and a low yield-to-tensile ratio.

The present application relates to the technical field of metal material heat treatment, in particular to a kind of multiphase Dievar hot working die steel and its heat treatment method, the method includes the following steps: S1 to be handled Dievar steel is austenitized;S2 after austenitizing Dievar steel is with first isothermal temperature T1 is salt bath isothermal quenching, and keeps t1 time, T1 lower than the martensite transition start temperature of Dievar steel M s Point;S3 with second heating rate fast heating to second isothermal temperature T2, and keeps t2 time, T2 higher than the M s Point;S4 after processing Dievar steel is cooled to room temperature, and multiphase Dievar hot working die steel is obtained.The present application obtains the multiphase structure of martensite+ bainite+ residual austenite by multiphase heat treatment technology, hardness is kept at higher level while impact toughness is significantly improved.Multiphase structure processing technology expands the application range of Dievar steel, and can be applied to more complex die.

This invention provides a high-strength Q&P steel with a low yield strength ratio of 960MPa and its production method. Its chemical composition, by mass percentage, is: C 0.15–0.17%, Si 0.4–0.6%, Mn 1.4–2.6%, Cr 0.4–0.8%, Ni 0.7–1.6%, Mo 0.2–0.6%, Nb 0.02–0.08%, V 0.02–0.08%, Ti 0.01–0.03%, Al 0.01–0.05%, Cu 0.8–1.6%, with the balance being Fe and unavoidable impurities. The production process, based on the above composition, employs controlled rolling and cooling combined with offline salt bath Q&P heat treatment to prepare a 15mm thick high-strength steel with a low yield strength ratio of 960MPa. The controlled rolling and cooling process employs a two-stage rolling process, and the heat treatment uses a two-step salt bath Q&P process. The complete austenitizing temperature is 900–920℃, the salt bath quenching temperature is 200–300℃, the salt bath partitioning temperature is 350–450℃, and finally, it is water-cooled to room temperature. The low yield strength ratio 960MPa grade high-strength steel plate of this invention has a yield strength ≥960MPa, a yield strength ratio ≤0.81, an elongation ≥15%, and an impact energy ≥35J at -40℃. The advantage of this invention lies in achieving a good performance match between high strength and a low yield strength ratio through the salt bath Q&P heat treatment process.

This invention discloses a test apparatus and method for isothermal heat treatment of wire rods. The test apparatus includes a loading rack, a heating furnace, a salt bath, and a robotic arm. The loading rack is used to place the wire rods to be heat treated; the heating furnace is used to heat the wire rods; the salt bath includes an upper salt tank and a first lower salt tank and a second lower salt tank located below the upper salt tank. A first heater in the first lower salt tank is used to heat the molten salt inside to a second set temperature, and a second heater in the second lower salt tank is used to heat the molten salt inside to a third set temperature. The second and third set temperatures are different. The first lower salt tank and the upper salt tank are circulatedly connected through a first conveying component, and the second lower salt tank and the upper salt tank are circulatedly connected through a second conveying component. A bracket is provided in the upper salt tank. The robotic arm is used to transfer the wire rods between the heating furnace, the bracket, and the loading rack. This invention can simulate the isothermal heat treatment process of salt bath under different molten salt flow fields and can also carry out graded isothermal heat treatment tests.

The application discloses an iron-based amorphous alloy strip with large tensile plasticity and work hardening capacity and a preparation method thereof. T g ~0.9 T g The yield ratio of the obtained iron-based amorphous alloy strip is 0.6-0.9 in the temperature range of 0.65 T g ~0.9 T g The yield ratio of the obtained iron-based amorphous alloy strip is 0.6-0.9 in the temperature range of 0.65 T g ~0.9 T g The yield ratio of the obtained iron-based amorphous alloy strip is 0.6-0.9 in the temperature range of 0.65 The application significantly improves the tensile plasticity of the iron-based amorphous alloy strip through cold-heat cycle treatment, and the work hardening capacity of the obtained iron-based amorphous alloy strip is obviously improved, the yield ratio of the iron-based amorphous alloy strip is 0.6-0.9 in the temperature range of 0.65

A carburized steel according to the present invention comprises, by wt%, 0.01 to 0.30% of C, 1.00% or less (excluding 0) of Si, 1.50% or less (excluding 0) of Mn, 2.00% or less (excluding 0) of Cr, 0.030% or less of P, 0.0500% or less of S, 0.3% or less of Ni, 0.30% or less of Mo, 0.30% or less of Cu, 0.500-0.01% of sol. Al, 0.100% or less of Nb, 0.30% or less of V, 0.050% or less of Ti, 0.0050% or less of B, 0.0200% or less of N, and the balance of Fe and inevitable impurities, and satisfies the following equations (1) and (2). Equation (1): [Al] / [C] ≥ 2.0 Equation (2): 0.4 ≤ [C]+(0.054×[Si])+(0.042×[Mn])+(0.015×[Cr])+(0.432×[Al]) ≤ 0.8 (wherein [Al], [C], [Si], [Mn], and [Cr] each represent the content (%) of the corresponding element).

The application relates to the technical field of heat treatment, in particular to a heat treatment system for high-strength tensile steel wire rope production, which comprises a pretreatment unit, an austenitizing heating unit, a quenching unit and a surface treatment unit. The pretreatment unit is used for straightening and cleaning treatment of the steel wire rope. The austenitizing heating unit is used for heating the steel wire rope to completely change into austenite organization. The heated steel wire rope is quenched by the quenching unit to complete the transformation from austenite to sorbite. The heat treatment system is used for heat treatment of the steel wire rope to improve the strength and tensile force of the steel wire rope. The austenitizing heating unit directly passes through a ceramic atmosphere plate to heat the steel wire rope in the rope cavity by using the electromagnetic induction heating principle, so that the temperature of the waste gas of the protective gas is lower when the waste gas is discharged.

The application provides a small-size high-strength spring steel and a production method and application thereof, the chemical components of the spring steel include C 0.64-0.69%, Si 1.38-1.58%, Mn 0.42-0.54%, Cr 0.52-0.67%, V 0.12-0.18% and satisfy the strength-plasticity index SE of 3.0-3.7%; the production method sequentially includes bloom continuous casting, high-speed wire controlled rolling, Stelmor wire controlled cooling and salt bath heat treatment; the wire rod prepared by the method is used to prepare automobile tail door spring steel wires, the tensile strength of the automobile tail door spring steel wires reaches 2275-2325 MPa, and the reduction of area is greater than or equal to 50%. The wire rod organization and performance of the spring steel are homogenized and regulated through the high-speed wire controlled cooling combined with the salt bath heat treatment and other processes, and the spring steel can be used to prepare high-strength automobile tail door springs.

This invention relates to the field of post-processing in metal additive manufacturing, and discloses a multi-stage synergistic heat treatment method for controlling residual stress in additive components. Addressing the problems of grain coarsening and impaired heat transfer in complex internal cavities caused by integral annealing, the additive component is immersed in a liquid metal medium at a temperature below the critical temperature for grain coarsening, achieving conformal heat transfer and homogenization of the substrate thermal field. Subsequently, a high-frequency alternating magnetic field and a constant DC bias magnetic field are orthogonally applied to the component. The high resistivity of the high-stress region is used to excite targeted Joule thermal increments, and ultrasonic elastic waves are in-situ excited based on dynamic Lorentz force to trigger acousto-plastic effects, achieving localized targeted stress release. During the cooling stage, a traveling wave magnetic field is applied to induce magnetohydrodynamic driving force, forcing the liquid metal to form forced convection circulation inside and outside the component, achieving uniform gradient synchronous cooling. Finally, the component is removed and the residual medium is removed. This invention releases residual stress while preserving fine-grain characteristics and avoids the generation of secondary thermal stress.

This invention provides a high-strength Q&P steel with a low yield strength ratio of 890MPa and its production method. The chemical composition of the thick plate, by mass percentage, is: C≤0.1%, Si 0.4~0.6%, Mn 1.4~1.8%, Cr 0.4~0.8%, Ni 0.6~1.0%, Mo 0.2~0.6%, Nb 0.02~0.08%, V 0.02~0.08%, Ti 0.01~0.03%, Al 0.01~0.05%, Cu 0.8~1.5%, with the balance being Fe and unavoidable impurities. The production process, based on the above composition, employs controlled rolling and cooling combined with offline salt bath Q&P heat treatment to prepare a 15mm thick high-strength steel with a low yield strength ratio of 890MPa. The controlled rolling and cooling process uses a two-stage rolling process: water cooling to 400~420℃ after rolling, followed by air cooling to room temperature. The high-strength steel plate of this invention, with a yield strength ≥ 890 MPa, a yield strength ratio ≤ 0.87, an elongation ≥ 15%, and an impact energy ≥ 100 J at -40℃, exhibits a good overall performance balance. The advantage of this invention lies in the use of a salt bath Q&P heat treatment process, which achieves a good combination of high strength, high and low temperature toughness, and a low yield strength ratio.