CN-121972786-A - Electron beam welding method for in-situ regulating welding joint molten pool composition

CN121972786ACN 121972786 ACN121972786 ACN 121972786ACN-121972786-A

Abstract

The invention provides an electron beam welding method for in-situ regulating and controlling welding joint molten pool components, and belongs to the technical field of advanced manufacturing of high-performance materials. According to the invention, the molten pool is filled with metal wires in the process of electron beam welding, and an in-situ regulation and control process scheme of the molten pool element components of the electron beam welding joint is realized by optimizing the process parameters of the electron beam welding, so that the supercooling degree of the molten pool components in the process of electron beam welding is changed, the material basis for reducing the performance difference between the molten pool and the matrix structure of the welding joint is changed, and a quantitative mapping relation between the process parameters of electron beam welding and the equilibrium concentration of the molten pool element is established, so that technical support is provided for realizing the precise regulation and control of the molten pool components and the structure of the electron beam welding joint of the metal materials, such as other high-performance titanium alloys, nickel-based high-temperature alloys and the like, and the precise regulation and control of the molten pool components and the structure are realized in the manufacturing process of electron beam welding or additive materials of other metal materials.

Inventors

ZHAO TONG
WANG CHUANYUN
TANG BIN

Assignees

西北工业大学

Dates

Publication Date: 20260505
Application Date: 20260114

Claims (4)

1. An electron beam welding method for in-situ regulating welding joint molten pool composition is characterized by comprising the following steps: s1, sample preparation, namely cutting a plate sample by using a wire-cut electric discharge machining technology, and cleaning the surface to be welded of the cut sample to expose clean and tidy metal materials; S2, electron beam welding, namely fixing the metal plate prepared by the sample on a welding platform, and setting an electron beam welding process parameter regulation range to perform electron beam welding, wherein in the process of electron beam welding, metal wires are filled in a molten pool in situ, and a fixed angle is kept between the metal wires and the surface of the sample, so that real-time regulation and control of the components of the molten pool are realized; S3, remelting a welding pool, namely carrying out low-power remelting on the welding pool area under the condition of not filling metal wires, wherein parameters of the remelting of the welding pool are set on the basis of the regulating and controlling range of the parameters of the electron beam welding process in S2; S4, performing postweld inspection, namely performing defect inspection on a welded joint weld, preparing a joint metallographic specimen, and characterizing a melting zone, a heat affected zone and matrix components, a microstructure and nano indentation hardness of the joint metallographic specimen; S5, constructing a quantitative mapping relation between the element components of the molten pool of the electron beam welding joint and the electron beam welding process parameters, namely constructing a quantitative mapping association relation between the element components of the molten pool of the electron beam welding joint and the electron beam welding process parameters according to the element contents and the ablation degree of the low-melting-point elements in the molten pool of the matrix and the filled metal wire based on a post-welding inspection result, determining the welding process parameters for acquiring the element contents in the molten pool based on the quantitative mapping association relation, and finishing the welding of the electron beam.
2. The electron beam welding method of in-situ regulating weld pool composition of claim 1, wherein S2 comprises the steps of: Fixing the metal plate prepared by the sample on a welding platform, preheating the plate to 100 ℃ and removing water; vacuumizing the cabin to maintain the vacuum degree at the level of 5X 10 -3 Pa; Setting an electron beam welding process parameter regulation range, filling a metal wire in the electron beam welding process, feeding the metal wire into a molten pool at a selected speed through a wire feeding device, and keeping an angle of 30-60 degrees with the surface of a sample, wherein the molten pool is the junction of the electron beam and the surface of a welding plate.
3. The electron beam welding method of in-situ regulating weld pool composition of claim 2, wherein S3 comprises the steps of: And (3) under the condition of no metal filling wire, carrying out low-power remelting on the welding pool area, adjusting the electron beam current to 0.5-1.0 times of the regulating range of the electron beam welding process parameters, and adjusting the welding speed to 1-4 times of the regulating range of the electron beam welding process parameters, wherein the remelting times are 1-3 times.
4. The electron beam welding method for in-situ control of weld pool composition according to claim 1, wherein the quantitative mapping association is expressed as follows: ; ; ; ; ; Wherein, the Represents the equilibrium concentration of element i in the bath, And Respectively representing the mass of the welding parent metal melted in unit time and the mass of the added metal wire melted in unit time, And Respectively represents the mass percent of the element i in the welding parent metal and the mass percent of the element i in the added metal wire, And The ablation rate of the element i in the welding parent metal and the ablation rate of the element i in the additive wire material are respectively represented, And The average ablation rate of the welding parent metal and the average ablation rate of the added metal wire are respectively shown, The density of the welding base material is shown, Indicating the welding speed and the welding speed, The melting sectional area, U the electron beam accelerating voltage, I the electron beam current, Indicating the latent heat of fusion of the welding parent metal, Represents the specific heat capacity of the material, Indicating the temperature rise, the temperature rise is shown, Representing the coefficient of thermal efficiency of the device, Indicating the density of the added wire material, Indicating the diameter of the added wire material, Indicating the rate at which the wire is added, Represents the vapor pressure of element i at the welding temperature, Indicating the vacuum level of the electron beam welding chamber, Indicating the length of the bath of molten metal, The coefficient of evaporation kinetics is indicated, The burn-out rate of the low-melting element i is shown.

Description

Electron beam welding method for in-situ regulating welding joint molten pool composition Technical Field The invention belongs to the technical field of advanced manufacturing of high-performance materials, and particularly relates to an electron beam welding method for regulating and controlling welding pool components of a welding joint in situ. Background The key structural member in the aerospace and nuclear energy industry field is used in extreme environments such as high temperature, high pressure, strong corrosion, complex alternating load and the like for a long time, and almost harsh requirements on material performance are put forward. The novel intermetallic compound material represented by Ti2AlNb is an ideal material for manufacturing high-pressure compressor disks, turbine blades, thermal protection structures of aerospace craft and key parts of nuclear reactors of aeroengines by virtue of excellent high-temperature strength, good oxidation resistance and relatively low density. However, engineering applications of these high performance materials face a common challenge in that complex structural members are difficult to manufacture by integral forming, and welding processes become an indispensable means of connection, and the quality and reliability of welded joints often determine the service life and reliability of the entire structure. The Ti2AlNb alloy belongs to a Ti-Al-Nb ternary intermetallic compound, the microstructure of the Ti2AlNb alloy is composed of an ordered O phase, a B2 phase and an alpha 2 phase, and the complex multiphase structure endows the material with excellent comprehensive performance, but also brings great difficulty to a welding process. The operating temperature of an aeroengine can reach six hundred to eight hundred degrees celsius and is subject to high-speed rotational loads of tens of thousands of revolutions per minute, and any welding defect or performance weakness may cause catastrophic failure. The requirements of the aerospace field on the structural reliability are more severe, the aircraft undergoes severe temperature gradient change and pneumatic load impact in the process of lift-off and reentry, and the welded joint must maintain structural integrity under transient thermal shock and continuous high temperature environments. Nuclear power equipment is subject to neutron irradiation, high-temperature and high-pressure coolant corrosion, and service cycle tests for decades, and the long-term stability of a welded structure is directly related to nuclear safety. In these application contexts, achieving high reliability welding of high performance metallic materials has become a key technical bottleneck restricting the improvement of equipment performance. The welding process is essentially an unbalanced metallurgical process with locally rapid heating and cooling, a property which inevitably results in a significant difference in microstructure of the welded joint area from the substrate. When a welding heat source acts on intermetallic compounds such as Ti2AlNb and the like, a molten pool area is subjected to complete melting and rapid solidification, and as the cooling rate is far higher than the equilibrium solidification condition, the weld metal tends to form a coarse columnar crystal structure, and crystal grains preferentially grow along the direction of the maximum temperature gradient. Meanwhile, the melted region retains a high-temperature phase due to rapid solidification, and is greatly different from the constituent phase of the base material structure. For Ti2AlNb alloy, the phase composition under the unbalanced solidification condition of the melting zone and the equilibrium phase composition of the base metal have obvious deviation, so that the mechanical behaviors of the two are obviously different. In addition, although the heat affected zone close to the weld line is not melted, the heat affected zone is subjected to a high-temperature peak value close to the melting point, the original fine equiaxed crystal structure is obviously coarsened, the balance structure proportion is broken, and the precipitated phase may be dissolved or coarsened. The low temperature heat affected zone, which is slightly distant from the weld, may then form a partially transformed structure due to insufficient temperature to induce a complete transformation. This gradient distribution of the structure from the center of the weld to the substrate constitutes an essential feature of the welded joint. The structural differences between the molten zone of the welded joint and the substrate have a versatile adverse effect on its service performance. Compared with the matrix, the molten zone structure is composed of coarse columnar single-phase grains, and the strength and hardness are lower due to the lack of a strengthening mechanism. Meanwhile, coarse columnar grains have limited capability of resisting dislocation local concentration, so that plastic def