94 results about "Martensite transformation" patented technology

The invention relates to the technical field of floating type platform mooring systems, and discloses a self-adaptive mooring cable, a manufacturing method and a self-adaptive mooring method.The self-adaptive mooring cable sequentially comprises a center main bearing layer, a middle protection layer and an outer self-adaptive regulation and control layer from inside to outside. The central main supporting layer is composed of synthetic fiber cables with high tensile strength; the middle protective layer wraps the periphery of the main bearing layer, is formed by weaving fiber materials and is used for preventing external media from invading; the outer-layer self-adaptive regulation and control layer covers the periphery of the protective layer and is woven into a net-shaped structure by shape memory alloy wires; the shape memory alloy woven mesh is configured to be capable of dynamically adjusting the overall rigidity of the mooring cable through thermoelastic martensite phase transformation based on environment temperature changes, and creep deformation of the synthetic fiber cable is slowed down. Through the synergistic effect of the three-layer structure, the structural stability and performance consistency of the mooring cable in long-term use are guaranteed.

The invention belongs to the technical field of metal processing technologies, and particularly relates to a gradient heat treatment steel strengthening and toughening technology optimization method which comprises the steps that a cooling tank is arranged, a vertical channel is formed in the inner side face of the cooling tank and communicates with a liquid layer in the cooling tank and the outer portion of the cooling tank, and quenching liquid is added into the cooling tank till the vertical channel is submerged; a proper amount of quenching oil is added, so that the quenching liquid and the quenching oil are layered, and a lower liquid layer and an upper oil layer are formed respectively; gradient heating is conducted on a target area of the workpiece in a local heating mode, and austenitizing is achieved; after the workpiece is austenitized, subarea gradient cooling is conducted, the workpiece is put into a cooling tank, quenching oil wraps the workpiece through an oil layer and continues to penetrate into a liquid layer, the surface layer of the workpiece reaches the martensite transformation termination temperature, and austenite is transformed into a martensite structure; the influence of a steam film generated when quenching liquid is used for quenching on the machining stability and the machining quality of a workpiece can be reduced.

The invention belongs to the technical field of metal materials, and discloses precipitation-hardening stainless steel and a preparation method thereof. Through cooperative regulation and control of component design and process innovation, the traditional contradiction of'strength-plasticity inversion 'in additive manufacturing of the precipitation-hardened stainless steel is broken through, and the precipitation-hardened stainless steel with excellent strength and plasticity is prepared. On one hand, the N element is introduced into the precipitation-hardening stainless steel raw material powder, so that transformation from ferrite to austenite in the additive manufacturing process is promoted; on the other hand, in the additive manufacturing process, the substrate is subjected to in-situ heating to be close to the martensite phase transformation initial temperature, and transformation of austenite to martensite is restrained; and after printing is finished, global martensite phase transformation is triggered through natural cooling or air cooling, so that a total martensite structure with fine grains and high dislocation density is obtained. And finally, through aging treatment, precipitation of a nano Cu phase is induced, formation of austenite is reversed, and therefore the strength and plasticity of the precipitation-hardened stainless steel are improved at the same time.

This invention discloses a high-elongation aluminum alloy for lightweight automotive components and its preparation method, relating to the field of aluminum alloy material technology. It features a hierarchical porous structure with surface micron-sized closed pores and a core nano-sized through-pore. The Ti and Mn elements synergistically form an Al-Ti-Mn martensitic phase transformation core region with Al, and the Cr element precisely controls the martensitic phase transformation initiation temperature to room temperature, ensuring stable triggering of the austenite-to-martensitic phase transformation and energy absorption during room-temperature collisions. This invention achieves initial impact buffering and gradual collapse energy absorption through a hierarchical porous structure with surface micron-sized closed pores and a core nano-sized through-pore. This dual energy absorption mechanism significantly improves the material's strength-ductility product, far exceeding that of traditional aluminum alloys.

To provide an information processing method, etc., that can perform simulations that reflect variations in the martensitic transformation initiation temperature. [Solution] The information processing method involves a computer that repeatedly performs the following steps to calculate the state of the object at the end of cooling: acquiring information about the shape of the object to be analyzed, acquiring physical properties of each phase and temperature of the steel constituting the object to be analyzed, acquiring information about the initial state of the object to be analyzed after heating, acquiring the results of a coupled analysis of the thermal conductivity analysis and elastoplastic analysis of the object to be analyzed after a time width Δt has elapsed, calculating the bainite fraction of the object to be analyzed based on the coupled analysis results, calculating the austenite fraction of the object to be analyzed based on the bainite fraction, calculating the martensitic transformation start temperature of the object to be analyzed based on the austenite fraction, and calculating the martensite fraction of the object to be analyzed based on the martensitic transformation start temperature.

The present application belongs to the technical field of metal materials, and discloses a precipitation hardening stainless steel and a preparation method thereof. Through synergistic regulation of component design and process innovation, the present application breaks through the traditional contradiction of "strength-plasticity inversion" in additive manufacturing of precipitation hardening stainless steel, and prepares a precipitation hardening stainless steel with excellent strength and plasticity. On the one hand, by introducing N element in the raw material powder of the precipitation hardening stainless steel, the transformation of ferrite to austenite in the additive manufacturing process is promoted; on the other hand, the substrate is heated in situ to the vicinity of the martensite transformation starting temperature in the additive manufacturing process, and the transformation of austenite to martensite is inhibited; and after the printing is completed, global martensite transformation is triggered by natural cooling or air cooling, so that the full martensite structure with fine grains and high dislocation density is obtained. Finally, through aging treatment, the precipitation of nano Cu phase is induced, and the formation of austenite is reversed, so that the strength and plasticity of the precipitation hardening stainless steel are simultaneously improved.

The invention relates to the technical field of black metal heat treatment, and discloses a structure modification strengthening process of a carbon fiber induced high-damping nodular iron casting, which comprises the following steps: austenitizing and preserving heat of the nodular iron casting with pre-buried directionally distributed carbon fiber bundles in a controlled carbon potential environment, so that a matrix forms a carbon concentration gradient field; quenching to be close to a martensite transformation starting point; intermittent spray cooling is executed through a cooling control unit in a martensite phase transformation interval; according to the method, martensite laths are induced to radially and directionally grow at an interface by utilizing a pulsating heat flow field generated by utilizing the axial high heat conduction characteristic of the carbon fibers, and a radial grain boundary structure with the carbon fibers as the axis is constructed, so that interface internal friction is generated by utilizing the radial grain boundary structure when a casting bears an excitation load, and vibration energy is dissipated; and the nodular iron casting generates damping response on the premise of maintaining the hardness of a matrix, and stress concentration at a heterogeneous interface is eliminated.

The invention provides a gradient functional composite material, a preparation method and application of the gradient functional composite material to a die-casting die. The composite material sequentially comprises a bonding layer, a metastable-state high-entropy alloy relaxation layer, a component gradient transition area and a dynamic densification composite surface layer from a base body to the surface. Wherein the relaxation layer can generate reversible martensite phase transformation at the die-casting temperature so as to actively dissipate thermal stress; the composite surface layer contains a low-melting-point nanophase, and can flow at high temperature to realize self-repairing and dynamic lubrication of surface micro-damage. According to the composite material, gradient transition and metallurgical bonding between layers are achieved through continuous process modulation. The coating system provided by the invention has multiple synergistic protection mechanisms of active stress digestion, interface gradient relaxation and surface self-adaptive repair, and can remarkably improve the thermal fatigue resistance, melting loss resistance and demolding performance of the die-casting die, so that the service life of the die is greatly prolonged.

The invention belongs to the field of automobile steel, and particularly relates to low-yield-ratio 980MPa-grade cold-rolled martensitic steel for an automobile and a preparation method. The steel comprises the following chemical components in percentage by weight: 0.125%-0.145% of C, 0.10%-0.20% of Si, 1.45%-1.60% of Mn, less than or equal to 0.020% of P, less than or equal to 0.0050% of S, 0.020%-0.055% of Als, less than or equal to 0.0050% of N, 0.02%-0.03% of Nb and the balance of Fe and other inevitable impurities. According to the method, the technical advantage of high cooling speed of a water cooling process path is fully exerted, on the basis that martensite transformation of annealed austenite is guaranteed, part of ferrite structures are introduced through part of slow cooling treatment and the low water quenching starting temperature, the martensite steel production technical scheme with the low yield ratio performance is achieved, the production process is simplified, and the production cost is reduced. The production cost is reduced.

The application discloses a nano-structured bainite steel and a preparation method thereof, and belongs to the technical field of steel materials. The preparation method comprises the following steps: subjecting raw material steel to austenitizing treatment; cooling to a bainite transformation temperature, and performing first-stage isothermal treatment; cooling to 20-200 DEG C below a martensite transformation start temperature; heating to the bainite transformation temperature, and performing second-stage isothermal treatment; after the second-stage isothermal treatment, cooling to room temperature, and obtaining the nano-structured bainite steel. Martensite is introduced between the first-stage and second-stage isothermal treatment, the austenite block is divided, the transformation rate of the bainite in the second-stage isothermal treatment is accelerated, the heat treatment time is shortened, and the bainite structure is refined; the bainite structure formed in the early stage serves as a flexible phase, can stabilize a part of thin film-shaped austenite, absorbs phase change distortion caused by the martensite formed in the intermediate stage, and avoids the cracking phenomenon of high-carbon steel in ordinary quenching or quenching and partitioning.

The application discloses a high-pressure quick connector based on precipitation hardening stainless steel and a production process thereof, and belongs to the technical field of materials. In the production process, carbon-coated NbC-Cu functional carbide is added as an additive. The carbon-coated NbC-Cu functional carbide contains a nano copper phase. Through low-temperature solid solution and aging treatment, two kinds of precipitated phases can be generated. One is a B2-NiAl precipitated phase in high-coherent relation with the matrix, and the other is an FCC-Cu precipitated phase in incoherent relation with the matrix. The high-pressure quick connector can generate phase transformation induced plasticity caused by the martensite transformation of austenite in the deformation process, and the FCC-Cu precipitated phase can capture the hydrogen evolution as an effective hydrogen trap to reduce the diffusible hydrogen content in the matrix to the maximum extent, thereby reducing the hydrogen embrittlement sensitivity while ensuring the good mechanical properties of the high-pressure quick connector.

The invention relates to the technical field of steel production, and discloses a method for regulating and controlling residual stress of additive high-strength steel through cooperation of thermal cycle and martensite phase transformation, and the method comprises the following steps: S1, collecting process information; s2, establishing a digital twinborn model according to the process information and predicting a residual stress field; s3, cooperative control parameters are generated through a control algorithm; s4, the heat source output device is controlled to melt the raw materials to form a new layer of geometric structure; and S5, on the basis of the cooperative control parameters, residual stress generated by thermal shrinkage is compensated or counteracted through the volume expansion effect of martensite phase transformation. According to the method, the residual stress is predicted through the digital twinborn model, the control parameters are generated to control non-melting thermal cycle to trigger martensite phase transformation at a precise time-space point, thermal shrinkage stress is compensated through phase transformation volume expansion, and therefore the precision and predictability of stress regulation and control are improved.

The invention discloses a preparation method of a high-bearing wear-resistant antifriction integrated functional layer on the surface layer of a shaft gear part. The preparation method comprises the following stages of a vacuum variable pulse carbon-nitrogen composite strengthening process, cryogenic treatment, low-temperature tempering and magnetron sputtering coating. A carbon-nitrogen composite strengthening layer is formed on the surface of the shaft gear part through the vacuum variable pulse carbon-nitrogen composite strengthening process to serve as a bearing layer; martensite transformation is promoted through subzero treatment, and the surface hardness is improved; the performance of the carbon-nitrogen composite strengthened layer is stabilized through low-temperature tempering; a high-wear-resistant film is formed by magnetron sputtering coating, and the high-wear-resistant film and the bearing layer jointly form an integrated functional layer. The wear rate can be greatly reduced, the limitation of a single carburizing and coating technology is broken through, the development trend and service requirements of heavy-duty gears and high-performance bearings of large equipment are met, the process integration degree is high, and important engineering application value is achieved.

The invention discloses a short-process low-cost titanium alloy plate and a preparation method thereof, and relates to the field of titanium alloy material preparation and structure property control. With Ti-Al-Cr-Fe-Zr as a research object, the preparation method comprises the following steps: (1) proportioning, smelting and pouring according to alloy components; (2) the alloy ingot is subjected to isothermal three-way forging at 950-970 DEG C, the squatting deformation is 30-50%, the drawing deformation is 20-40%, and the alloy ingot is air-cooled to the room temperature after four-heating-number forming; and then hot rolling is conducted at the temperature of 775-790 DEG C, the total deformation is 75%, the single-pass deformation is 12.5%, remelting heat preservation is conducted for 10-15 min between passes, finally air cooling is conducted to the room temperature, and the short-process low-cost high-strength plastic titanium alloy plate which is uniform in structure, excellent in performance and capable of inducing martensite phase transformation under the stress effect is obtained.

The present application belongs to the field of on-line repair of steel rail, and particularly relates to a preparation of a super-high strength complex-phase steel repair layer and a method for regulating the structure and performance thereof. After 30CrMnSiA powder and elemental metal powder are weighed according to a proportion, the elemental metal powder is mixed, the elemental metal powder is Ni 0.50-0.80wt%, Mo 0.30-0.60wt%, and the balance is 30CrMnSiA powder; the 30CrMnSiA plate is used as a base material, and a thermodynamic calculation software is used to determine that the martensite transformation start temperature of the deposited metal powder is 272.1-348.5℃ and the bainite transformation temperature interval is 272.1-461.4℃; according to the calculation result of the above-mentioned metal solid phase transformation temperature interval, the base material is preheated to a specified temperature of 270-320℃; a non-contact infrared temperature detector is used to on-line monitor the surface temperature of the base material and the deposited metal, and when the surface of the base material reaches the set temperature, laser deposition is started. According to the service condition requirements of the material, the mechanical performance and hydrogen embrittlement resistance of the material can be regulated in a large range, and the repair layer has high strength and toughness and low hydrogen embrittlement sensitivity.

This application provides a high-entropy alloy-induced carbide precipitation-strengthened iron-based high-temperature wear-resistant coating and its preparation method, relating to the field of high-temperature wear-resistant coating technology. The method includes drying high-entropy alloy powder and iron-based alloy powder; mixing the dried powders; and then using laser cladding equipment to prepare the coating. The material used in this application achieves martensitic transformation strengthening and carbide synergistic strengthening by precisely controlling the precipitation of eutectic carborides during solidification using high-entropy alloys. During solidification, δ-Fe nucleates and grows first. As the liquid phase composition changes to near the eutectic point, Cr and Mo carborides (MC) begin to nucleate and grow. At this point, δ-Fe begins to transform into γ-Fe, which then undergoes a martensitic transformation. After cooling to approximately 700°C, the phase transformation nearly stops, and C only diffuses short-range to form M6(CB) type carborides, promoting the synergistic strengthening mechanism of the material and balancing strength and toughness.

The invention relates to the technical field of high-strength steel material welding, in particular to a stranded low-temperature phase change welding wire and a preparation and welding method thereof. A stranded structure formed by the center wire and the peripheral wires is adopted, the chemical component proportion of the whole welding wire is accurately controlled by changing the number, the diameter and the combination mode of the center wire and the peripheral wires, particularly, the chromium content is controlled to be 9%-12%, and the nickel content is controlled to be 8%-11%; the martensite phase transformation starting temperature of weld metal is accurately set in an ideal interval from 200 DEG C to room temperature, beneficial pressure stress is actively generated by utilizing martensite phase transformation of the weld metal in the specific temperature interval, inherent welding residual tensile stress is counteracted, and active and in-situ regulation and control of the welding residual stress are achieved; in addition, a magnetic field unit is applied in the martensite phase transformation process, and the regulation and control effect of the residual stress is further improved.

The invention discloses a method for optimizing the performance of 20CrMn-N duplex stainless steel based on a gradient cold rolling process, and relates to the technical field of steel alloy material strengthening preparation. Saving type duplex stainless steel is prepared through hot rolling and then subjected to solution treatment, then a four-roller cold rolling mill is adopted for cold rolling deformation, and the performance of the 20CrMn-N duplex stainless steel is optimized through gradient control over the cold rolling deformation amount. And the metastable austenite is subjected to controllable strain-induced martensite phase transformation, the volume fraction of martensite can be regulated and controlled, the 20CrMn-N-series LDSS steel plate containing a three-phase structure of ferrite, austenite and strain-induced martensite is obtained, accurate controllable strengthening of strength-plasticity is achieved through a simple and convenient process, the strengthening effect and performance customization flexibility are both considered, and the production cost is reduced. The three-phase structure evolution can be directionally regulated and controlled, and the strength and toughness and the surface quality are synergistically improved.

The invention discloses a FeMnSi series alloy with a remarkable room-temperature shape memory effect for 3D printing. The FeMnSi series alloy is prepared from the following elements in percentage by mass: 16% of Mn, 7.5%-8.2% of Cr, 3.5%-4.2% of Ni, 5.5%-5.7% of Si and the balance of Fe. The invention further discloses a preparation method of the FeMnSi series alloy. According to the FeMnSi alloy, the proportion with the characteristics of low Cr, low Ni and medium Si is designed, the martensite phase transformation point temperature is effectively increased, meanwhile, the internal stacking fault and dislocation defect density of the FeMnSi alloy is increased through 3D printing, phase transformation from an fcc phase to an hcp phase in the room-temperature deformation process and inverse phase transformation after heating are promoted, the remarkable shape memory effect and tensile strength are achieved at the room temperature, and the high-strength and high-toughness FeMnSi alloy is obtained. The method is suitable for preparing impact-resistant, load-bearing and functional devices which can be repeatedly used in a room-temperature environment.

The invention provides a high-temperature low-expansion alloy forge piece and a manufacturing method thereof. The high-temperature low-expansion alloy forge piece comprises, by mass, 31.0%-33.5% of Ni, 7.0%-9.0% of Co, smaller than or equal to 0.20% of Nb, smaller than or equal to 0.04% of C, smaller than or equal to 0.20% of Si, smaller than or equal to 0.25% of Mn, smaller than or equal to 0.02% of P, smaller than or equal to 0.02% of S, smaller than or equal to 0.20% of Cr, smaller than or equal to 0.20% of Mo, smaller than or equal to 0.1% of Al, smaller than or equal to 0.1% of Ti, smaller than or equal to 0.1% of Zr, smaller than or equal to 100 ppm of N, smaller than or equal to 50 ppm of O and the balance Fe and inevitable impurities. The alloy forge piece prepared through the method is large in section, the average linear expansion coefficient in the wide temperature range of 20-500 DEG C is low, the martensite phase transformation temperature is smaller than or equal to-60 DEG C, and the excellent high-temperature low-expansion performance is achieved.

The invention discloses a method for measuring the original austenite grain size of high alloy steel through an X-ray diffractometer method, and belongs to the technical field of metal material detection. According to the method provided by the invention, nondestructive testing is realized by establishing the quantitative relation model of the martensite phase change product and the original grain size, chemical erosion and mechanical damage of a traditional metallographic method to a sample are avoided, the method can be directly used for quality inspection of a finished product, and a new technical means is provided for whole-process quality control of a steel product; an optimized diffraction peak analysis algorithm is combined, so that the measurement precision is remarkably improved; the detection process is simple, convenient and efficient, the single detection time can be shortened to be within 30 minutes, the detection efficiency is greatly improved, and the method is particularly suitable for rapid detection requirements of batch samples.

This invention belongs to the field of metastable austenitic stainless steel preparation technology, and discloses a method for preparing metastable austenitic stainless steel with a controllable ultrafine / micron-grained bimodal heterostructure. The method includes: firstly, in M… s Point and M d Metastable austenitic stainless steel sheets are cold-rolled between points, with the deformation amount controlled at 10%-80%, to obtain rolled sheets with specific phase contents through deformation-induced martensitic phase transformation; subsequently, at a temperature higher than M... d The material is subjected to warm rolling deformation to 80% of the total deformation under conditions below the recrystallization temperature; finally, it is subjected to short-time annealing treatment at 700-750℃. This invention can achieve quantitative control of the ratio and size of micron and submicron crystals by adjusting the initial cold rolling deformation and subsequent annealing treatment, which solves the problems of high randomness in the preparation of heterogeneous structures and difficulty in preparing large sizes in the prior art. The resulting material has excellent strength and plasticity matching, and the process is efficient and easy to industrialize.

The invention provides a method for improving the hardness of a 0Cr12Mn5Ni4Mo3Al material, and belongs to the technical field of heat treatment.The method comprises the steps that 1, adjustment treatment is conducted on a 0Cr12Mn5Ni4Mo3Al part, so that carbide is separated out from austenite; 2, the adjusted part is subjected to cold treatment and then dried, and martensite transformation treatment is completed; and 3, aging treatment is conducted on the part subjected to cold treatment, so that the hardness of the part meets the requirement. 0Cr12Mn5Ni4Mo3Al belongs to precipitation hardening stainless steel, the supply state is a hard state or a semi-hard state, precipitation hardening is generated through heat treatment aging, and the strength, hardness and elasticity of the material are improved.

The application provides a cold and hot quenching oil. The quenching oil comprises the following components in percentage by mass: base oil 86-90%, rapid cooling agent 6-9.5%, antioxidant 2.5-3.5% and dispersant 1-2.5%; wherein the base oil is composed of 150N mineral oil and paraffin-based 10# white oil in a mass ratio of 1:(1.2-1.7). The quenching oil can not only improve the cooling rate in the high-temperature section, so that the supercooled austenite reaches the martensite transformation temperature zone at a large cooling rate, but also reduce the cooling rate in the low-temperature section, so that the thermal stress and thermal deformation are reduced, and the quenching and hardening capacity is good.

The invention belongs to the technical field of metal material heat treatment, and particularly relates to Cu-containing high-carbon bainite complex-phase steel based on isothermal quenching and a preparation technology. The invention relates to a high-temperature-resistant steel plate, which comprises the following chemical components in percentage by mass: 0.65 to 0.70 percent of C; 1.80% to 1.90% of Si; 1.00% to 1.10% of Cr; 1.05% to 1.10% of Ni; cu: 0.52 to 1.12%; 0.38% to 0.42% of Mo; wherein the balance is Fe and inevitable impurities with the total amount smaller than 0.05%. The microstructure of the Cu-containing high-carbon bainite complex-phase steel comprises a superfine bainite ferrite batten, retained austenite and a dispersed epsilon-Cu precipitated phase, and the width of the bainite ferrite batten is smaller than 200 nm. The material adopts high carbon and high silicon, and the complex-phase bainite steel is prepared by austenitizing a steel billet and then carrying out isothermal quenching heat treatment at the temperature above the martensite transformation starting temperature. The Cu-containing high-carbon bainite complex-phase steel has the advantages of high strength, high hardness, good plasticity and good toughness in the aspect of mechanical properties, the preparation process is simple, and industrial production is easy.

The invention relates to the technical field of metal heat treatment, and discloses an anti-hydrogen embrittlement carburizing heat treatment process for a high-strength self-tapping screw, which comprises the following steps: placing a workpiece in a carburizing furnace, heating to carburizing temperature, and executing multi-cycle pulse carburizing, including a strong carburizing stage and a diffusion stage; a sulfur-containing atmosphere is introduced in the workpiece heating and diffusion stage; after carburization is finished, the workpiece is subjected to high-pressure air cooling, the temperature of the workpiece is reduced to be higher than the martensite phase transformation point, then the workpiece is immediately immersed into an in-situ passivation quenching medium for liquid cooling, and a liquid-phase hydrogen barrier is established in the medium-temperature phase transformation window period; and the quenched workpiece is subjected to low-temperature tempering. According to the invention, through a double cooperation mechanism of high-temperature dynamic sulfur potential control and medium-temperature in-situ passivation quenching, the invasion of hydrogen is inhibited from the source in the whole process, so that the diffusible hydrogen content of the workpiece is extremely low. Therefore, according to the process, the hydrogen embrittlement risk is eliminated, the hydrogen removal baking procedure is not needed, meanwhile, quenching deformation is reduced through segmented controlled cooling, and the product size precision is guaranteed.

The invention relates to the technical field of heat treatment quenching media, in particular to quenching oil special for 05Cr15Ni5Cu4Nb precipitation hardening stainless steel and a preparation method and application of the quenching oil. The special quenching oil for the 05Cr15Ni5Cu4Nb precipitation hardening stainless steel is prepared from the following components in percentage by mass: 88 to 95 percent of base oil combination, 1.5 to 5.0 percent of quick cooling agent, 2.0 to 3.5 percent of antioxidant and 1.0 to 4.0 percent of dispersing agent, the base oil composition is a mixture composed of refined hydrogenated mineral oil 150N and refined hydrogenated mineral oil 500N; the quick cooling agent is polyisobutene; the antioxidant is a combination of phenyl-alpha-naphthylamine and dialkyl dithiophosphate carbamate, or a combination of phenyl-alpha-naphthylamine and dilauryl thiodipropionate, and the antioxidant is a combination of phenyl-alpha-naphthylamine and dilauryl thiodipropionate. Through base oil compounding and rapid cooling agent dosage optimization, the step quenching effect of high-temperature rapid cooling and low-temperature slow cooling is achieved, martensite transformation of a 05Cr15Ni5Cu4Nb precipitation hardening stainless steel workpiece is stably completed near the Ms point, and a uniform and fine lath martensite structure is provided for subsequent aging strengthening.

The invention belongs to the technical field of austenitic stainless steel materials, and particularly relates to an ultralow-temperature austenitic stainless steel material and a preparation method and application thereof. The austenitic stainless steel material comprises, by weight, 0.05%-0.07% of C, 1.0%-2.0% of Mn, 0%-0.6% of Si, smaller than or equal to 0.015% of S, smaller than or equal to 0.035% of P, 19.0%-19.5% of Cr, 9.0%-10.5% of Ni, N larger than or equal to 500 ppm and larger than or equal to 1000 ppm, and the balance iron and inevitable impurities. And the austenite content is greater than or equal to 98.5%. Chemical components and gas components of the material are strictly controlled, so that the martensite transformation temperature is reduced, the structure is kept in a stable austenite structure state, and the content of unstable austenite of the material is further reduced through subzero treatment in the heat treatment process; and a foundation is laid for the stability of the pump or other equipment used under the ultralow-temperature working condition.

The invention relates to the field of textile equipment, in particular to a groove pin and a quenching method thereof.The method comprises the following steps that (S.1) the groove pin is heated to the critical temperature or above, so that the groove pin is wholly or partially austenitized; (S.2) providing an asymmetric temperature field, wherein the asymmetric temperature field has a preset temperature difference; and (S.3) the heated groove pin is placed in the temperature field and makes contact with the temperature field, so that the two sides of the groove pin are rapidly cooled under the condition of different cooling rates, and martensite transformation and quenching are completed. Through active regulation and control of an asymmetric cooling field, thermal stress and structural stress in the quenching process are remarkably inhibited, the deformation amount of the groove pin is extremely controlled, the high-precision geometric dimension of the groove pin is effectively guaranteed, synchronous cooling and phase change of different parts of the groove pin are achieved on the basis of the temperature difference compensation principle in the City, and the service life of the groove pin is prolonged. And the uniformity of hardness distribution and the compactness of a microscopic structure are greatly improved, so that the wear resistance is enhanced, and the overall service life is prolonged.

The invention relates to the technical field of processing of modified iron-based alloy materials for precision molds, and discloses a preparation method of a modified iron-based alloy material for a precision mold with a low expansion characteristic, and the preparation method comprises the following steps: performing induction melting on a matrix, and introducing niobium and vanadium to construct a nucleation center; performing forging, spheroidizing annealing and austenitizing treatment on the blank; in the spraying cooling stage, the secondary change trend of the surface layer temperature along with the time change is monitored in real time so as to recognize the crystallization latent heat characteristic, then the spraying duration time is adjusted, and a martensite structure distributed discretely is induced and generated in the blank. And through dynamic balance adjustment of cold flow energy and latent heat release, a prestress field opposite to a thermal expansion vector is constructed, and the dimensional stability of the material under the high-hardness working condition is effectively improved.