7 results about "Weld microstructure" patented technology

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.

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.

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.

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.