36 results about "Hardenability" patented technology

This invention provides a 590MPa grade solid welding wire, a laser-arc hybrid welding process, and a welded joint. The composition system of this invention is precisely adapted to the rapid heating and cooling thermal cycle characteristics and the burn-off law of key alloying elements in laser-arc hybrid welding of 590MPa grade marine engineering steel. By strictly controlling the content of highly hardenable elements such as C, Mn, Ni, and Mo, the formation of hardened structures in the weld metal is avoided. A certain amount of Ti element is added to provide nucleation points within the grains, directionally inducing the formation of a highly oriented and complex acicular ferrite matrix structure, thereby simultaneously improving strength and toughness through grain refinement. At the same time, an appropriate amount of V element is added to further improve the strength margin of the weld metal through microalloying. This welding wire has excellent welding processability and crack resistance, and can achieve room temperature welding without preheating or post-heating, providing material support for the high-quality and high-efficiency construction of marine engineering equipment.

This invention discloses a process for improving the hardenability of wind turbine main shafts during heat treatment, comprising the following steps: heating 42CrMo4 steel ingots to 1180~1220℃ for forging, with a forging ratio ≥4; air-cooling the forgings to 650~700℃ for the first time before loading them into a furnace, holding them at 300~350℃, then raising them to 640~660℃ for a second holding, with the holding time determined by the effective thickness × 1.5min / mm, followed by cooling to room temperature; vertically loading the forgings into tooling and heating them to 8... The surface is held at 40~860℃ for 1.2~1.5 min / mm (effective thickness × 1.2~1.5 min / mm) until the surface temperature drops to 780~800℃. Then, it is quenched in PAG solution within 3 minutes of quenching. After quenching, it is transferred to a tempering furnace and heated to 300℃ at a rate of ≤80℃ / h, held, and then heated to 540~580℃ at a rate of ≤100℃ / h, held for 2.0~2.5 min / mm (effective thickness × 2.0~2.5 min / mm). After tempering, it is cooled at a rate of ≤50℃ / h. This invention refines grains and carbides through forging and upsetting processes, controls pearlite cluster size through normalizing, and improves cooling uniformity through a density-layered dual-medium system during quenching. This method is suitable for improving the hardenability of large cross-sections in high-power wind turbine main shafts.

The application discloses a process for improving corner crack of 16MnCr5 steel hot-rolled blank, which comprises the steps of slow cooling before heating, heating, blooming rolling and slow cooling after rolling; the slow cooling before heating step: the blank is first slowly cooled for more than or equal to 72 hours; the heating step: the segmented heating control is adopted, the heating temperature of the first heating section is 850-950 DEG C, the heating temperature of the second heating section is 1110-1150 DEG C, the temperature of the soaking section is 1100-1180 DEG C, and the total heating time is controlled to be 4-5 hours; the blooming rolling step: nine passes of rolling are adopted, the reduction of the first four passes is 50-60 mm, the reduction of the middle four passes is 20-30 mm, and the reduction of the last pass is 10-20 mm; the hot-rolled blank is obtained; and the slow cooling after rolling step: the hot-rolled blank is slowly cooled for more than or equal to 72 hours. The application reduces or eliminates the generation of surface cracks of the wire rod, guarantees good hardenability of the product, and effectively improves the product quality.

The application relates to PG2 steel forged large-length-ratio thick-wall pipe material capable of bearing high temperature, high strength and high-low temperature impact and a heat treatment process. The material is PG2 steel, and the chemical components include the following according to mass percentage: C: 0.28-0.33%; Si: 0.15-0.35%; Mn: 0.75-0.95%; Cr: 1.80-2.10%; Ni: 3.00-3.50%; Mo: 1.20-1.40%; V: 0.20-0.35%; W: 0.20-0.50%; P: <=0.010%; S: <=0.005%; Cu: <=0.10%; Al: <=0.030%, and the balance is iron. Through sectional heating grain refinement and structure regulation technology, and in combination with the use of an inner hole cooling special tool installed at the bottom of a water tank, the PG2 steel forged large-length-ratio thick-wall pipe is uniformly and rapidly cooled, so that the mechanical properties and grain size of the PG2 steel forged large-length-ratio thick-wall pipe meet the design target, the material has high hardenability, the steel has normal temperature and 700 DEG C strength and low temperature impact toughness after quenching and tempering, and the requirements of high strength and high toughness are met.

This invention belongs to the field of metallurgical technology and relates to a production method for 22CrMoNbH heavy-duty niobium-containing gear steel. The method comprises three parts: chemical composition design, smelting production, and rolling production. The smelting process employs a four-stage process of "converter smelting – LF refining – RH vacuum degassing + continuous casting," precisely controlling impurity content and alloy uniformity. The rolling process utilizes "temperature-controlled rolling – slow cooling," optimizing microstructure and properties through dual electromagnetic stirring, temperature-controlled rolling, and slow cooling treatment. This invention, through niobium microalloying and synergistic process innovation, achieves a gear steel grain size ≥8 and a hardenability bandwidth ≤3HRC, significantly improving comprehensive mechanical properties and fatigue resistance. It can directly replace imported high-end heavy-duty gear steel, offering good production economics and is suitable for heavy-duty gear manufacturing in the automotive, heavy machinery, and other fields.

The application discloses a kind of low alloy high hardenability ultra-high strength steel and its preparation method, with mass percent, its chemical composition is C:0.29~0.33%, Mn:1.30~1.60%, Si:1.30~1.60%, Cr:1.10~1.40%, Ni:0.40~0.50%, Mo:0.30~0.50%, V:0.08~0.15%, Cu:≤0.20%, Ti:0.02~0.06%, B:0.001~0.005%, Al:0.01~0.06%, S:≤0.0060%, P:≤0.013%, the balance is Fe.The application is based on 30CrMnSiA, by trace addition alloying element Ni, Mo, V, Ti, B, Al, and cooperate production process to obtain the high-strength steel of strength 1600MPa grade;Strength is also obtained excellent hardenability while promoting, not only can be used as civil structural material, also can be applied to military industry.

This invention discloses a high-strength cold-rolled steel with excellent baking performance, which contains Fe and unavoidable impurities, and also contains the following chemical elements in the following mass percentages: C: 0.06-0.10%, 0 < Si ≤ 0.05%, Mn: 0.40-0.7%, Al: 0.03-0.05%; the microstructure of the high-strength cold-rolled steel has recrystallized equiaxed ferrite with a volume fraction of more than 95%, and slender ferrite extending along the rolling direction with a volume fraction of 3-5%. This invention also discloses a method for manufacturing high-strength cold-rolled steel, comprising the following steps: smelting and continuous casting; hot rolling: the furnace exit temperature is 1150-1250℃, the hot rolling final rolling temperature is 830-890℃, the coiling temperature is 520-650℃, laminar flow cooling is adopted after rolling, and the rapid cooling rate of the laminar flow front section is 80-120℃ / s; pickling and cold rolling; continuous annealing: controlling the annealing homogenization temperature to be 680-750℃; leveling.

This invention relates to the field of heat treatment methods and discloses a quenching and tempering heat treatment process for 42CrMo1 steel based on end-quenching value control. The process includes steps 1: pre-quenching and tempering preparation (related end-quenching value preset), 2: quenching treatment (core end-quenching value control step), 3: tempering treatment (stress relief and microstructure stabilization), 4: post-quenching and tempering quality verification (related end-quenching value feedback), and 5: finished product identification and archiving. This process achieves a balance between hardenability and quenching cracking risk, reducing the scrap rate through "precise control of Ti element + synergistic optimization of main alloy composition." It avoids excessive hardenability caused by excessive main alloy composition and refines grains and improves hardenability through Ti element, reducing the quenching cracking rate from 16.8% to below 3%. Out of 925 steering knuckles, only 30 were scrapped due to quenching cracking (cracking rate 3.25%). Furthermore, by reducing the stirring frequency (from 20Hz to 18Hz), the cracking rate in subsequent batches was further reduced to around 1%, completely solving the problem of "hardenability versus cracking." The core contradiction.

This invention relates to the field of iron and steel metallurgy, particularly to a steel for track links in engineering machinery and its manufacturing process. The steel contains C, Si, Mn, Ca, Cr, Al, Ti, Nb, B, Mo, and N. The production process includes electric furnace smelting, LF ladle refining, RH vacuum treatment, continuous casting, heating, rolling, and cooling. Based on 15B36Cr steel, this invention increases the Cr content to 1.00%–1.20% to improve its wear resistance and increase the hardenability of the core of large-size track links. It also incorporates 0.020%–0.035% Nb to form a “B-Nb-Ti-Al” synergistic microalloying system. Simultaneously, it optimizes inclusion control by controlling Ca and sulfur content to ensure a calcium-sulfur ratio ≥1.5, thereby enhancing the steel's corrosion resistance and avoiding or reducing the risk of fracture.

The purpose of an aspect of the present invention is to provide: a cold-rolled steel sheet and a plated steel sheet for vehicles, each simultaneously having excellent low-temperature bake hardenability and good aging resistance, and excellent workability; and methods for manufacturing same.

Disclosed is a martensitic stainless steel with excellent hardenability through the control of a component system. The martensitic stainless steel with excellent hardenability comprises, in percent by weight (wt %), 0.01 to 0.1% of C, 0.05 to 0.1% of Si, 0.05 to 1.0 of Mn, 11.0 to 14.0% of Cr, 0.05 to 1.0% of Ni, 0.05 to 2.0% of Cu, 0.04 to 0.08% of N, and the balance of Fe and inevitable impurities, and satisfies Formula (1).wherein Mn, Ni, and Cu denote contents (wt %) of elements, respectively.

The application discloses a kind of high tough high hardenability hot die steel and preparation method thereof, belong to alloy steel field, a kind of high tough high hardenability hot die steel and preparation method thereof, component ratio includes following mass percentage elements: C:0.40-0.50%;Si:0.20-0.40%;Mn:1.20-1.60%;Cr:1.50-1.80%;Ni:1.65-1.85%;Mo:0.35-0.50%;V:0.15-0.25%, S≤0.005%, P≤0.015%, N≤120ppm, O≤80ppm, H≤1.5ppm;The balance is iron and unavoidable impurities.The application can be not greatly increased under the premise of cost, provide a kind of high tough high hardenability hot die steel and preparation method thereof, its formula and process scientific and reasonable, after alloying smelting is passed through forging and heat treatment, the die steel prepared has relatively high strength and impact toughness, simultaneously has higher hardenability.

The present application relates to the field of metal material forging and heat treatment process, disclose a kind of based on tug 90kN level high-performance bitt's forging method, including preparation by industrial deionized water, film-forming main agent A, film-forming auxiliary agent B, sodium molybdate dihydrate, polyethylene glycol 400 and triethanolamine are quenched medium and heated constant temperature;After alloy structural steel blank is heated to heat, multiple-pass forging is carried out to obtain forgings;The forgings are pre-cooled to the first temperature, immersed in the quenching medium for first stage cooling, and the flow rate is controlled to maintain the first circulation flow rate;When the surface temperature of the forgings decreases to the second temperature, switch and maintain the second circulation flow rate for second stage cooling;When the core temperature of the forgings decreases to the water temperature, the forgings are lifted out and naturally cooled in still air, and the residual sensible heat is used to complete the self-tempering of the residual heat.The present application balances the cooling rate, avoids surface microcracks and improves the core hardenability.

The application belongs to the technical field of metal materials, and provides a 550MPa-grade low-temperature steel with low brittle transition temperature and a manufacturing method.The chemical composition system of low carbon and low manganese is adopted in the component design, the segregation tendency of continuous casting billet in the thickness direction is reduced, Nb, V-N, Ti and other micro-alloy elements are added to refine the grain, Ni, Cr, Mo and other alloy elements are added to improve the hardenability of the steel, the uniformity of the performance in the thickness direction is improved, the purity of the molten steel and the quality of the continuous casting billet are improved through La, Ca, Mg, Zr and other elements, and the performance uniformity in the thickness direction of the steel plate is further improved.The structure of the steel plate is polygonal ferrite + tempered sorbite, the yield strength of the low-temperature steel is 600-650MPa, the tensile strength is 700-750MPa, the elongation after fracture is greater than or equal to 23.5%, and the impact energy at-85℃ is greater than or equal to 175J;the brittle transition temperature T kb of the full thickness is less than or equal to-65℃.The steel plate has excellent mechanical properties and low brittle transition temperature.

An aspect of the present invention is to provide a cold-rolled steel sheet and a manufacturing method thereof. A preferred aspect of the present invention is to provide a cold-rolled steel sheet having excellent low-temperature bake hardenability and room-temperature aging resistance and a manufacturing method thereof.

This invention discloses a high-life, low-cost, large-size round steel bar for hydraulic breaker chisels and its manufacturing method. The chemical composition of the round steel bar, by mass percentage, is: C: 0.32~0.42%, Si: 0.5~1.4%, Mn: 0.80~1.50%, P: ≤0.025%, S: ≤0.015%, Cr: 1.00~1.40%, Cu: ≤0.25%, Mo: 0.05~0.10%, Nb: 0.02~0.04%, Al: 0.015~0.035%, H: ≤0.0002%, with the balance being Fe and unavoidable impurities. The diameter of the round steel bar ranges from 150 to 250 mm. The manufacturing method includes converter / electric furnace smelting, LF refining, RH / VD degassing, continuous casting, billet surface treatment, round steel rolling, and cooling processes, each with precise process parameter control. The round steel prepared by this invention has good hardenability and excellent strength-toughness matching. The service life of the drill rod made from it is 2-3 times longer than that of 42CrMo, and the amount of Mo added is significantly reduced, effectively controlling production costs. At the same time, it improves the atmospheric corrosion resistance of the drill rod, making it suitable for large-scale hydraulic breakers in mining, building demolition and other fields.

The application discloses a production method of high-strength and high-toughness gear steel without normalizing treatment. The gear steel adopts a Cr-Mn based hardenability system and is micro-alloyed by V, Nb and Al. The production process comprises smelting, continuous casting, controlled rolling and controlled cooling, and a key heat treatment process of directly slow cooling to quenching temperature after high-temperature carburizing. The V, Nb and Al carbonitrides pin the grain boundaries at high temperature, and inhibit the growth of austenite grains during the carburizing process. The application enables the gear steel to be directly quenched without normalizing treatment after high-temperature carburizing, and fine crystal structure and high comprehensive performance are obtained, so that the production process is greatly simplified, and the cost and energy consumption are reduced.

The application discloses a high-wear-resistance heavy-load transmission screw rod heat treatment and machining integrated method and relates to the technical field of screw rod machining, and specifically comprises the following steps: rough thread turning pretreatment is carried out on a high-strength alloy structural steel screw rod blank after quenching and tempering treatment, surface oxide layers and oxide skins are removed, and a finishing allowance is reserved; a tooth root plasma synchronous micro-boron infiltration activation process is carried out on a thread tooth root area, so that a boron content gradient is formed on the tooth root surface; the screw rod blank after the micro-boron infiltration activation treatment is transferred to an induction quenching station on line, and integral synchronous induction quenching heat treatment is carried out; and finally, thread tooth forming grinding machining is carried out on line; through the synergistic effect of the tooth root plasma synchronous micro-boron infiltration activation process and the integral synchronous induction quenching, a uniform boron content gradient and a phosphorus content gradient are formed on the thread tooth root, the hardness of the tooth root is ensured to be higher than that of the tooth tip, the hardenability of the tooth root is significantly improved, and the service life of the screw rod is prolonged.

The application relates to the technical field of welding materials, in particular to a continuous oil pipe butt welding gas protection solid core welding wire and a welding method; the chemical components of the solid core welding wire include the following: C: 0.08%-0.14%, Si: 0.2%-0.3%, Mn: 0.7%-1.0%, Ni: 0.15%-0.25%, Cu: 0.25%-0.35%, Cr: 0.5%-0.7%, Mo: 0.10%-0.15%, Nb: 0.02%-0.03%, Ti: 0.01%-0.02%, and the rest is Fe and inevitable impurities; by adopting low-carbon components, the fatigue performance of a weld is reduced, then the Mn, Ni, Mo, Cr and Cu systems are adopted, and i and Nb trace elements are added at the same time, so that the solid solution strengthening, fine-grain strengthening and precipitation strengthening methods can be comprehensively utilized to improve the strength of the weld, the hardenability of the weld metal is improved, the generation of bainite is promoted, the toughness and strength of the metal weld are improved, and therefore the fatigue resistance of a pipe-pipe butt welding joint is comprehensively improved.

This invention provides a steel sheet with excellent hardenability and excellent cold workability. The steel sheet disclosed herein has the following composition by mass %: C: 0.50~0.90%, Si: 0.01~0.50%, Mn: 0.20~1.30%, P: less than 0.100%, S: less than 0.100%, Al: less than 0.100%, Cr: 0.01~1.20%, N: less than 0.0150%, and the balance being Fe and impurities. The total surface area of ​​ferrite and cementite particles is 95% or more, the average grain size of ferrite is 5.0~20.0 μm, and the Cr concentration in the cementite particles is [Cr]. θ Less than 2.00%, Mo concentration [Mo] θ The content is below 1.00%, the average particle size of cementite particles is below 1.50 μm, and the spheroidization rate of cementite particles is above 85%.

This disclosure provides a steel sheet with excellent hardenability and excellent cold workability. The steel sheet disclosed herein has the following composition by mass %: C: 0.15~0.50%, Si: 0.01~0.50%, Mn: 0.20~1.30%, P: less than 0.100%, S: less than 0.100%, Al: less than 0.100%, Cr: 0.01~1.20%, N: less than 0.0150%, and the balance being Fe and impurities. The total surface area of ​​ferrite and cementite particles is 95% or more, the average grain size of ferrite is 5.0~20.0 μm, and the Cr concentration in the cementite particles is [Cr]. θ and Mo concentration [Mo] θ To satisfy equation (1), the average particle size of the cementite particles is less than 1.50 μm, the spheroidization rate of the cementite particles is greater than 70% and less than 85%, and the dispersion DI of the number of cementite particles in a small square partition with a side length of 10 μm, as defined by equation (2), is less than 45%. 2[Cr] θ +3[Mo] θ ≤3 / √C (1) DI=σ θ / N θ ×100 (2)

This invention belongs to the field of casting technology and mainly relates to a production method for thick-walled cast steel parts, including the following steps: design of the chemical composition of the cast steel parts; design of the heat treatment process: the cast steel parts are treated with a heat treatment method of high-temperature annealing + quenching + high-temperature tempering in sequence. By adjusting the content of a wide range of constituent elements required by the customer, and adding trace elements Nb and B strengthening elements when designing and optimizing the internal control composition, the hardenability of the cast steel material is significantly improved; and combined with the heat treatment process of high-temperature annealing + quenching + high-temperature tempering, the relevant parameter ranges and steps of each heat treatment process are designed reasonably to ensure that the entire cross-section of the cast steel part obtains a uniform tempered sorbite structure, and that the strength, plasticity, and average Akv of the surface, half radius, and core of the cast steel part all meet the standard requirements; the performance compliance rate of the finally obtained cast steel parts is 100%.

This invention relates to the field of metallurgical technology and discloses a high wear-resistant and fatigue-resistant generator spindle and its preparation method. The chemical composition of the spindle includes C, Si, Mn, Cr, Ni, Mo, Ce, Nb, B, etc., with Ti strictly limited to ≤0.003%, and no aluminum deoxidizer is added throughout the process. The preparation method includes: electric arc furnace carbon pre-deoxidation; LF refining to produce high-basicity slag; VD vacuum refining for vacuum carbon deoxidation, and sequential feeding of cerium-iron cored wire, niobium-iron, and boron-iron using a specific timing sequence. This invention uses the generation of spherical rare earth oxide sulfides as a core to induce the precipitation of niobium carbonitrides to form a core-shell structure to fix nitrogen and protect boron in a solid solution state. This technical solution eliminates large-size TiN and Al2O3 inclusions, effectively solves the problem of boron failure in titanium-free steel, and endows the spindle forging with excellent deep hardenability, extremely high fatigue strength ratio, and good transverse impact toughness.

This disclosure provides a steel sheet with excellent hardenability and excellent cold workability. The steel sheet disclosed herein has the following composition by mass %: C: 0.15~0.50%, Si: 0.01~0.50%, Mn: 0.20~1.30%, P: less than 0.100%, S: less than 0.100%, Al: less than 0.100%, Cr: 0.01~1.20%, N: less than 0.0150%, and the balance being Fe and impurities. The total surface area of ​​ferrite and cementite particles is 95% or more, the average grain size of ferrite is 5.0~20.0 μm, and the Cr concentration in the cementite particles is [Cr]. θ and Mo concentration [Mo] θ To satisfy equation (1), the average particle size of the cementite particles is less than 1.50 μm, the sphericity of the cementite particles is greater than 85%, and the dispersion DI of the number of cementite particles in a small square partition with a side length of 10 μm, as defined by equation (2), is less than 45%. 2[Cr] θ +3[Mo] θ ≤3 / √C (1) DI=σ θ / N θ ×100 (2)

This invention belongs to the field of special steel materials technology, and relates to a high-strength, high-hardenability 20CrMnTiH gear steel and its preparation method. The composition (%) is: C: 0.19–0.22, Si: 0.18–0.25, Mn: 1.05–1.15, Cr: 1.10–1.20, Ti: 0.045–0.055, V: 0.08–0.12, Al: 0.020–0.035, P≤0.010, S≤0.005, TO≤8ppm, N≤45ppm, H≤1ppm; the balance is Fe and unavoidable impurities. This invention solves the technical bottlenecks of insufficient hardenability, low strength, and large performance fluctuations in traditional 20CrMnTiH gear steel through composition design, composite microalloying control, full-process purity control, and integrated innovation of heat treatment processes. It provides a gear steel that can be industrially produced and has excellent comprehensive performance.

This invention provides a steel sheet with excellent hardenability and excellent cold workability. The steel sheet disclosed herein has the following composition by mass %: C: 0.50~0.90%, Si: 0.01~0.50%, Mn: 0.20~1.30%, P: less than 0.100%, S: less than 0.100%, Al: less than 0.100%, Cr: 0.01~1.20%, N: less than 0.0150%, and the balance being Fe and impurities. The total surface area of ​​ferrite and cementite particles is 95% or more, the average grain size of ferrite is 5.0~20.0 μm, and the Cr concentration in the cementite particles is [Cr]. θ Less than 2.00%, Mo concentration [Mo] θ The content is less than 1.00%, the average particle size of cementite particles is less than 1.50 μm, and the spheroidization rate of cementite particles is more than 75% and less than 85%.

This invention discloses a method and apparatus for predicting and analyzing the hardenability of steel based on a regression system, relating to the field of materials heat treatment technology. The method includes: preparing test samples of different steel grades and conducting hardness measurement experiments on the samples; constructing datasets for each steel grade based on experimental data; constructing regression relationships between the chemical composition and end-quench curve characteristic parameters of different steel grades based on the datasets; fitting and reconstructing the experimental data for different steel grades to build parameterized hardenability prediction models suitable for different steel grades. This invention systematically designs the processing, regression modeling, and parameter calling processes of end-quench experimental data, which reduces the reliance on repeatable physical end-quench tests while ensuring prediction accuracy, providing rapid and repeatable data support for steel grade design and process optimization.

This invention relates to the field of alloy technology, specifically to a high-strength nickel-chromium-silicon reinforced copper alloy and its preparation method. The alloy uses copper as a matrix, with added nickel, silicon, and chromium. By optimizing the two-form, two-time addition method of chromium (adding chromium flakes first, followed by copper foil-coated chromium powder), combined with heat treatment processes such as short-time pre-aging, deep cryogenic shock, low-temperature micro-deformation, and two-stage final aging, the microstructure uniformity of thick-section products is significantly improved. The resulting alloy possesses high tensile strength, high hardness, and good electrical conductivity, making it suitable for high-end applications such as injection molds, effectively solving the problems of insufficient hardenability and large performance fluctuations in traditional alloys.