16 results about "Weld microstructure" patented technology

The invention belongs to the technical field of microstructure simulation in the solidification process, and particularly relates to a nickel-based superalloy laser welding solidification structure evolution law prediction method and system.The method comprises the steps that simulation parameters are determined, a macroscopic temperature field is simulated to obtain molten pool temperature field data, a cellular automaton model is constructed, and grids are divided; initializing state variables such as component concentration and solid-phase fraction; coupling temperature field data, solving an optimized solute diffusion and redistribution equation to obtain a concentration field, updating a solid phase fraction according to local supercooling drive, and marking grain growth; counting a solid-phase fraction, and updating a solid-phase position; and judging whether the temperature of the cladding layer is lower than the solidus temperature and the solid fraction reaches a complete solidification threshold value or not, and if yes, outputting weld microstructure and target element concentration data. According to the method, the evolution law of the welding macroscopic temperature field and the structure and solute concentration field can be effectively predicted, experiments are replaced with numerical simulation, the cost is reduced, the technical blank is filled up, and reliable support is provided for precise regulation and control of the nickel-based high-temperature alloy laser welding process.

This invention belongs to the field of metallic materials, specifically relating to a welded steel plate with an aluminum-silicon coating and its preparation method. Based on a chromium-nickel-manganese ternary alloying approach, this invention eliminates the need for pre-welding coating removal or reducing the total amount of aluminum-silicon coating entering the weld seam through beveling. High-performance aluminum-silicon coated hot-formed steel welded joints can be obtained using conventional laser filler wire welding. Currently available welding wires are mainly composed of austenitic stabilizing elements, while this invention innovatively designs the welding wire composition system. The welding wire is designed using a composite of non-austenitic stabilizing elements chromium, nickel, and manganese in a specific ratio, and the chromium-nickel equivalent ratio of the welding wire is controlled to achieve full martensiticization of the weld microstructure. The purpose of this invention is to obtain welded joints reaching the level of the base material in a low-cost and high-efficiency manner, which is of great significance to the development of laser welding technology for aluminum-silicon coated steel.

The invention discloses a method for improving corrosion resistance of an austenitic stainless steel weld joint. A base material is 304L austenitic stainless steel; laser welding conditions; the welding seam is cleaned; 3-6 times of single cycle treatment is carried out; performing cold deformation; bright annealing; cooling is performed; circulating according to the step 4) until a set single cycle number is reached; and performing vacuum dehydrogenation heat treatment. Through the combined effect of cold deformation and heat treatment, the austenitic stainless steel welding seam structure performance is improved, stress and crystal defect distribution of a welding seam area are changed, the welding seam structure is subjected to static recrystallization, original thick columnar crystals are converted into fine isometric crystals, and therefore the corrosion resistance of the welding seam area is remarkably improved; and in addition, the process is simple, and implementation can be effectively combined with an existing welding production line.

This invention discloses a post-weld heat treatment process to improve the strength and toughness of welded joints made of 1600MPa grade ultra-high strength steel. The core technology utilizes a composite heat treatment of "precision quenching + low-temperature tempering" to solve the problem of strength-toughness mismatch caused by elemental segregation and uneven microstructure in the welded joint. The process involves oil quenching at 840-850℃ for 5.4-5.8 hours, followed by oil cooling at 200-220℃ for 7.4-7.8 hours. This effectively reduces the segregation of Cr, Mo, W, and Si elements, transforming the weld microstructure from martensite to tempered martensite and precipitating uniform carbides. After treatment with this invention, the tensile strength of both the base metal and the weld joint is ≥1740MPa, the impact energy of the weld joint is increased to over 34J, the impact energy of the base metal reaches over 69J, and the uniformity of hardness distribution is improved by 40%. This process is suitable for welded components made of 1600MPa grade ultra-high strength steel in the automotive, aerospace, and other fields, significantly improving service safety and lifespan.

This invention belongs to the field of welding materials and high-temperature resistant structural material preparation technology, specifically relating to a flux-cored wire and its preparation method that can suppress the agglomeration of nano-dispersed phases in ODS steel welds. The method involves composite Fe-9Cr alloy matrix powder with nano-SiO2, Al, and Ti reinforcing phases, constructing a uniformly dispersed multiphase composite flux-cored system through high-energy ball milling, and then encapsulating it with H08A steel strip to form a stable flux-cored structure. By precisely controlling the ball milling process parameters, flux filling rate, and the metallurgical behavior of the outer sheath material, the flux filling powder can rapidly precipitate in the weld after melting in the arc zone and maintain a nano-level dispersed state, thereby effectively avoiding the oxide particle coarsening and agglomeration phenomena commonly seen in traditional ODS steel welding. This invention provides a new approach for the development of ODS steel welding materials, solves the problem of maintaining the stability of weld microstructure in high-temperature structural materials, and has significant application value in fields such as nuclear energy, aerospace, and advanced energy equipment.

This invention discloses an Al-Cu welding wire, its preparation method, and its application, belonging to the field of laser welding technology. The welding wire is prepared by weighing various components, including aluminum, aluminum-copper master alloy, aluminum-titanium master alloy, aluminum-magnesium master alloy, aluminum-silicon master alloy, aluminum-manganese master alloy, aluminum-scandium master alloy, and aluminum-zirconium master alloy, according to a designed welding wire composition ratio. These components are then melted and cast to obtain an ingot. The ingot undergoes multi-stage homogenization treatment, followed by hot rolling and wire cutting. This invention improves the proportion of isometric regions in the weld microstructure by introducing trace amounts of Sc, Si, Ti, and Zr into a low-cost, high-Cu content weld pool system, refining the weld microstructure and enhancing mechanical properties compatible with Al-Cu-Li alloys. Furthermore, by reducing the content of the hard and brittle W phase through appropriate processes, the invention effectively ensures the machinability of the welding wire and the weld performance.

This invention discloses a welding wire and welding method for reducing the breakage rate of normalized welds in high-silicon non-oriented silicon steel. The welding wire comprises the following chemical composition by mass percentage: C: 0.15%–0.20%, Si: ≤0.35%, Mn: 2.0–2.5%, Ni: 2.0–2.5%, Cr: 0.8–1.0%, with the remainder being Fe. The welding method includes laser welding of non-oriented silicon steel using the above welding wire as filler material. This invention, through optimization of the welding wire composition and welding process, controls the weld microstructure, forming a bainitic structure, enhancing ductility and toughness, achieving a 100% cupping test pass rate, and a normalized weld breakage rate ≤0.05%.

The invention provides a method for improving the flattening performance of a medium-small-caliber high-carbon-equivalent thick-wall HFW (High Frequency Welding) pipe blank, which is characterized in that a low-carbon microalloy rolled plate is prepared into the medium-small-caliber high-carbon-equivalent thick-wall HFW pipe blank by adopting the processes of FFX (Fin Fin X) forming, HFW welding, hot tension reducing, graded cooling and the like. By means of the method, the welding extrusion amount can be remarkably increased, welding seam inclusion and bad structures are reduced, the pipe blank welding seam structure performance is similar to or consistent with the base metal structure performance, and the forming and welding seam quality problems caused by small pipe diameter, wall thickness increasing and carbon equivalent increasing of the pipe blank are prevented.

This invention discloses an automated welding method for optimizing the weld microstructure of a nickel-based alloy composite plate. The nickel-based alloy composite plate includes a substrate layer and a nickel-based alloy composite layer, with a transition layer at the interface between the substrate layer and the nickel-based alloy composite layer. The automated welding method includes the following steps: machining a trapezoidal bevel on the welding cross-section of the nickel-based alloy composite plate corresponding to the position of the substrate layer; machining a U-shaped bevel on the welding cross-section of the nickel-based alloy composite plate corresponding to the position of the transition layer; not machining a bevel on the welding cross-section of the nickel-based alloy composite plate corresponding to the position of the nickel-based alloy composite layer; performing self-fusion welding of the nickel-based alloy composite layer using laser welding; using a carbon steel welding wire matched to the substrate layer, performing filler wire welding of the transition layer using laser welding; and welding the substrate layer using hot-wire oscillating tungsten inert gas welding.

The application discloses an industrial welding quality evaluation system based on visual detection and relates to the technical field of industrial welding quality detection.The system comprises a multi-field coupling micro-excitation unit, a resonance visual signal acquisition unit, a resonance feature extraction unit, an excitation evolution mapping calibration unit, a reversibility evaluation unit, an evolution trend prediction unit and a mass production full inspection adaptation unit.In the application, the multi-field coupling micro-excitation is used to trigger the resonance of the weld microstructure and capture non-stationary resonance visual signals.Combined with the closed-loop design of the three-dimensional mapping calibration library and the resonance peak shift rate-failure cycle model, the problems that the prior art cannot establish the correlation between macro and micro defects, cannot distinguish the reversibility of defects, cannot predict the evolution trend of irreversible defects and has poor mass production full inspection adaptability are solved, the quantitative evaluation of weld micro defects, the accurate determination of reversibility and the prediction of failure trend are realized, the anti-interference capability and mass production full inspection efficiency are taken into account, and the detection and repair are coordinated.

A welding method for heterogeneous multi-wire in-situ metallurgy of submerged arc welding (SAW) pipes in hydrogen transportation pipelines is disclosed. This invention aims to address the hydrogen-induced failure problems caused by traditional SAW methods, such as coarse weld microstructure, secondary phase particle aggregation, and reduced low-temperature impact toughness. The welding method includes: 1. Grinding and cleaning the surface of the hydrogen transportation pipeline to be welded; 2. Welding the cleaned hydrogen transportation pipeline using three-wire SAW. The first welding wire is H08MnMoTiB, the second is BH60GX-III, and the third is H08Mn2NiA. The composition of the three welding wires is optimized, and the wire feed speed, current, and voltage are adjusted accordingly. This invention integrates the concept of in-situ metallurgy with SAW, changing the wire feed speed of different welding wires to achieve a certain alloy composition ratio in the weld pool transition metal. Combined with different welding process parameters, this allows for quantitative adjustment of the weld cladding metallurgical properties, thereby improving resistance to hydrogen corrosion.

This invention discloses a welding method for optimizing the weld microstructure of a nickel-based alloy composite plate. The nickel-based alloy composite plate includes a base material layer and a nickel-based alloy composite layer, with a transition layer at the interface between the base material layer and the nickel-based alloy composite layer. The welding method includes the following steps: machining a trapezoidal bevel on the welding section of the nickel-based alloy composite plate corresponding to the position of the base material layer; machining a U-shaped bevel on the welding section of the nickel-based alloy composite plate corresponding to the position of the transition layer; not machining a bevel on the welding section of the nickel-based alloy composite plate corresponding to the position of the nickel-based alloy composite layer, retaining a blunt edge; welding the nickel-based alloy composite layer using single tungsten inert gas (TIG) welding; welding the transition layer using single TIG welding; and welding the base material layer using single TIG welding.

The embodiment of the invention relates to the technical field of welding, in particular to a method suitable for detecting a single crystal welding seam, and the method comprises the following steps: determining a to-be-detected sample; cutting the to-be-detected sample according to a predetermined requirement, and determining an observation surface of the to-be-detected sample; the observation surface is treated, and the weld structure morphology on the observation surface is obtained; according to the weld structure morphology, a fusion line and a corresponding metallographic image in the fusion line are determined; according to the metallographic image, determining a first area of a target welding seam structure area and a second area of all independent crystal grains in a fusion line; and according to the first area and the second area, the single crystal degree of the single crystal welding seam is determined. According to the method provided by the embodiment of the invention, the detection result of the single crystal welding seam is not directly determined by simply depending on a metallographic image, but the single crystal degree of the single crystal welding seam can be accurately determined according to the determined first area and the second area, so that the error in the process of determining the detection result is favorably reduced, and the reliability of the detection result is improved.

This invention belongs to the field of laser arc welding technology, and particularly relates to a laser-arc double-sided composite multi-layer welding method for thick plate T-joints. The steps are as follows: workpiece preparation, including surface treatment of the workpiece; workpiece fixing, including beveling the bottom end of the stiffener plate in the workpiece, fixing the stiffener plate and base plate, and leaving a gap between the stiffener plate and base plate; pre-welding preparation, including installing welding torches and lasers on both sides of the stiffener plate and fixing them with auxiliary devices, connecting the welding torch power supply to the workpiece and welding torch, and connecting the laser power supply to the laser; welding operation, starting the laser and welding torch to begin welding, first performing the root pass welding, and after the root pass welding is completed, performing multi-layer filler welding. Utilizing these structures, the efficiency of root pass welding and multi-layer welding of thick plate T-joints is improved, the stability of the laser and arc welding process is enhanced, welding defects such as incomplete penetration / fusion and porosity are avoided, and the weld microstructure and mechanical properties are improved.

This invention discloses an electromagnetic coupling treatment device and process for annular welds. The device includes an inner electromagnetic coil, an inner annular thin copper strip electrode, an outer annular thin copper strip electrode, and an outer electromagnetic coil arranged coaxially from the inside out. The inner annular thin copper strip electrode has at least two circumferentially distributed outwardly convex protrusions on its sidewall along the generatrix direction, and the outer annular thin copper strip electrode has at least two circumferentially distributed inwardly concave protrusions on its sidewall along the generatrix direction. The surfaces of the outwardly and inwardly convex protrusions are in contact with the surface of the annular weld. This invention designs inner and outer annular thin copper strip electrodes with surface protrusion structures, and uses the magnetic pulses generated by the inner and outer electromagnetic coils to make them adhere to the annular weld. By applying pulsed current to the annular thin copper strip electrodes and coordinating with the magnetic fields loaded by the inner and outer electromagnetic coils, time-division loading of the electro-magnetic coupling energy field of the annular weld is achieved, thereby improving the weld microstructure and stress state more efficiently and stably.

The application belongs to the technical field of welding manufacturing, and discloses a "light-filament-powder" coaxial variable-frequency adjustable microstructure programming laser welding method and device. The device mainly comprises a laser welding system, a "light-filament-powder" coaxial feeding mechanism, a molten pool real-time temperature monitoring device and a self-adaptive variable-frequency regulator. The method realizes stable and synchronous feeding of filament and powder welding materials by using the "light-filament-powder" coaxial feeding mechanism, and based on a laser vision sensing device, the temperature distribution characteristics of the molten pool and the solidified weld are monitored in real time, the microstructure morphology is deduced, and the variable-frequency sub-control is adjusted to feed the filament, the powder and the laser energy waveform, so that the weld microstructure customization programming control welding is finally realized. The "light-filament-powder" coaxial variable-frequency adjustable microstructure programming laser welding method has high filling efficiency, strong adjustment ability and controllable weld microstructure, and solves the problems of frequent defects, uneven microstructure and performance in the welding process of complex structures.