CN-116703858-B - Method and system for calculating dilution rate of welded joint

Abstract

The disclosure belongs to the technical field of welding data processing, and provides a method and a system for calculating a dilution rate of a welding joint, wherein a metallographic photograph of the welding joint is obtained; copying the outline of the welding line and the fusion line of the welding line on the metallographic photograph, determining the size of a groove, drawing the original shape of the joint at the corresponding position of the macroscopic metallographic photograph, calculating the fused cross-sectional area of the base metal of the welding joint and the cross-sectional area of the welding line, and calculating the dilution rate of the welding joint. The method can realize direct measurement of the dilution rate, avoid a plurality of problems of indirect measurement, has good adaptability, is suitable for various groove types and various welding methods, and is beneficial to pushing the research and development of the welding process and the quality evaluation of the joint.

Inventors

• SUN XIAOHONG
• CUI YUNLONG
• WANG REN
• HE JIANYING
• ZHANG SHIXIN
• ZHANG RENHANG
• KAN XIAOYANG
• LI KE
• Jing Hanyang

Assignees

• 中车青岛四方机车车辆股份有限公司

Dates

Publication Date

20260512

Application Date

20230606

Claims (8)

1. 1. The method for calculating the dilution rate of the welding joint is characterized by comprising the following steps of: obtaining a metallographic photograph of a welded joint; copying the outline of a welding line and a welding line on the metallographic photo; determining the size of a groove, and drawing the original shape of the joint at the corresponding position of the macroscopic metallographic photograph; calculating the cross section area of the welded joint parent metal and the cross section area of the welding seam, and calculating the dilution rate of the welded joint; Determining the size of a groove, drawing the original shape of a joint at the corresponding position of a macroscopic metallographic photo, and dividing a welding line into a plurality of closed areas; And calculating the cross sectional area of each closed area according to a plurality of closed areas divided by the welding line, and further calculating the melted cross sectional area of the base metal of the welding joint and the cross sectional area of the welding line.
2. 2. A method of calculating the dilution ratio of a welded joint according to claim 1, characterized in that the metallographic image is imported into computer aided design software before copying the contours of the weld and its weld line on the metallographic image.
3. 3. The method for calculating the dilution ratio of the welded joint according to claim 2, wherein the magnification of a unit length is determined, the size of the macroscopic metallographic photograph is adjusted, and after the macroscopic metallographic photograph is adjusted to a set size, the outline of the weld and the weld line is copied.
4. 4. The method of claim 1, wherein the principle of dividing the closed areas is that no overlapping area exists between the areas, and the sum of the closed areas is the outline area of the whole joint shape; The region of the cross-sectional area into which the weld joint base material is melted is not referred to as a separate region.
5. 5. The method of claim 1, wherein if the joint is angularly deformed more than a set value, a deformation angle of the joint is measured, whereby the deformation angle rotates the original shape of the joint around the reference point in the deformation direction.
6. 6. A weld joint dilution ratio calculation system, comprising: The image receiving module is configured to acquire a metallographic photograph of the welding joint; a profiling module configured to copy contours of the weld and its weld lines on the metallographic photograph; the original shape drawing module is configured to determine the size of the groove and draw the original shape of the joint at the corresponding position of the macroscopic metallographic photograph; The calculation module is configured to calculate the cross-sectional area of the welding joint parent metal melting in and the cross-sectional area of the welding joint, and calculate the dilution rate of the welding joint; Determining the size of a groove, drawing the original shape of a joint at the corresponding position of a macroscopic metallographic photo, and dividing a welding line into a plurality of closed areas; And calculating the cross sectional area of each closed area according to a plurality of closed areas divided by the welding line, and further calculating the melted cross sectional area of the base metal of the welding joint and the cross sectional area of the welding line.
7. 7. A computer readable storage medium, characterized in that a plurality of instructions are stored, which instructions are adapted to be loaded by a processor of a terminal device and to perform the steps of the method of any of claims 1-5.
8. 8. A terminal device comprising a processor for implementing instructions and a computer-readable storage medium for storing instructions adapted to be loaded by the processor and to perform the steps of the method according to any one of claims 1-5.

Description

Method and system for calculating dilution rate of welded joint Technical Field The disclosure belongs to the technical field of welding data processing, and particularly relates to a method and a system for calculating a dilution rate of a welding joint. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. The dilution ratio refers to the percentage of the cross-sectional area of the weld joint to the cross-sectional area of the weld joint in which the base material is melted. As shown in FIG. 1, when the compositions of the material A and the material B on both sides of the weld are different, the dilution ratio induced by the base material A is D A＝FA/(FA+FB+F1, and the dilution ratio induced by the base material B is D B＝FB/(FA+FB+F1). When the components of the material A and the material B on the two sides of the welding line are the same, the dilution ratio caused by the base material is D= (F A+FB)/(FA+FB+F1). In all fusion welded joints, a certain amount of base metal is burned by a welding heat source and mixed with filler metal to form a weld. Since the composition of the filler metal is different from that of the base metal, the dilution ratio caused by the base metal directly determines the composition of the weld joint, and thus the structure and performance of the weld joint metal are affected. It can be seen that the dilution rate is an important concept in the technical field of welding, and is particularly critical to research directions such as dissimilar metal welding, surfacing welding, novel groove welding process test, new welding process research and development and the like. However, the current engineering technology lacks an effective method for directly measuring dilution ratio. To the inventors' knowledge, two methods are currently in common use to indirectly determine the dilution ratio of a welded joint. The first is an element calculation method, which calculates the dilution ratio by measuring the contents of several elements in the weld structure according to the difference between the contents of the base metal and the filler metal elements. The method has the following problems that firstly, the method has high requirements on equipment, the content of elements in micro areas of a welding seam is required to be measured by means of equipment such as a scanning electron microscope, secondly, the elements in each area of the welding seam are unevenly distributed, and a plurality of micro areas are required to be selected in the welding seam for measurement, so that the cost and the time are further increased, thirdly, the elements of a base metal and a filling metal are burnt to a certain extent in the welding process, the measuring precision of the method is obviously reduced due to the loss of the elements, and fourthly, the method needs to firstly corrode a sample to determine the welding seam area to carry out subsequent element measurement, and the corrosion process can interfere with the measurement of the elements to further influence the measuring precision of the method. It is for several reasons mentioned above that elemental measurements are not only less accurate (errors approaching 20%) but also more costly, and therefore this method has not been widely used. The second method is a model calculation method, the weld joint shape is simplified, different algorithms such as a genetic neural network, an Elman grid algorithm, a response surface method, statistical analysis and the like are adopted, a model for calculating the dilution rate through technological parameters such as welding current, welding speed and the like is established, and the dilution rate is calculated through a mathematical model. However, the model has a plurality of defects, such as no consideration of the effect of the filling metal, difficulty in directly establishing a relation with the dilution ratio, and the like, and the contrary conclusion is easy to be obtained by adopting the model to research the relation between the heat input and the dilution ratio. In addition, the model collects basic data through a simple build-up test, and is verified through the build-up test, and the build-up process is greatly different from the conventional welding process, so that the model is not suitable for most welding processes, is not suitable for common groove types, and is not regulated according to actual conditions such as misalignment, welding deformation and the like. Based on the above reasons, the model calculation method has poor adaptability and low calculation accuracy, so that the method is not widely applied. In summary, based on the above-mentioned two calculation methods, it is necessary to change the thought and develop a method for directly measuring the dilution ratio of the welded joint according to the definition of the dilution ratio. Disclosure of Invention In order to so