All-position welding process stability evaluation method based on mechanical property of gas shielded welding wire

Abstract

The invention discloses an all-position welding process stability evaluation method based on the mechanical property of a gas shield welding wire. The method comprises the following steps that S1, the mechanical property of the welding wire is measured; s2, the elastic-plastic ratio rD and the strain strengthening factor sD of the welding wire are obtained; s3, constructing a wire feeding stability comprehensive factor SWF; and S4, a criterion of wire feeding stability and all-position welding process stability is established, and therefore all-position welding process stability evaluation is conducted on the to-be-evaluated welding wire. According to the method, the stability of the gas shield solid welding wire all-position welding process can be indirectly evaluated without actual arc-starting welding.

Description

Technical Field

[0001] This invention relates to the field of welding evaluation technology, and more specifically, to a method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire. Background Technology

[0002] Currently, solid wire gas metal arc welding (GMAW) is the most commonly used welding method in various industrial fields. It boasts advantages such as mature and stable technology, convenient operation, high efficiency, and low cost. By matching specific welding materials and welding process specifications, it can meet the structural integrity and safety requirements of various application scenarios, including conventional static mechanical properties, dynamic fatigue performance, corrosion resistance, and high-temperature resistance. However, the welding of many industrial structural components often involves complex spatial welding positions, such as all-position welding of pipelines, welding of energy medium storage tanks and spherical tanks in complex spatial positions, and vertical and overhead welding of important steel structures. In these non-flat and horizontal welding positions, the weld droplets undergo unstable transitions due to gravity, and the spreadability of the weld pool deteriorates due to gravity. The combination of these factors adversely affects the stability of the welding process, thus posing a significant challenge to welding quality. In this application scenario, the impact of wire feeding stability on welding process stability will be amplified. If the impact of the wire feeding stability can be effectively evaluated through the mechanical properties of the wire itself, the stability of the welding process in all positions of the relevant wire products can be indirectly evaluated. This will provide technical guidance and reference for wire selection and welding quality prediction in engineering projects without the need for actual arc initiation welding.

[0003] Currently, there are many publicly available technical documents concerning the evaluation of the welding suitability of gas-shielded solid welding wire, such as:

[0004] Chinese patent application CN200910091678.4 discloses a surface condition criterion for evaluating wire feeding performance. By extracting the ratio of the flat area to the total area of ​​the wire surface and the average width of the largest flat area on the wire surface, and applying quantitative constraints, a wire feeding stability criterion based on the surface condition of the wire is obtained. This criterion can be used to evaluate stainless steel and nickel-based alloy welding wires for welding methods such as TIG, MIG, and MAG. However, this evaluation method is based on alloy steel welding wires with lower strength and hardness and are prone to plastic deformation, and is not suitable for carbon steel and low-alloy steel welding wires.

[0005] Chinese patent application No. 201811465450.2 discloses a device and method for evaluating the welding process performance of gas-shielded welding (GSW) wire. This method uses a high-speed camera and a signal synchronous recorder to simultaneously acquire welding images, arc voltage, and welding current during the welding process of the GSW wire under test. Computer signal processing is then used to detect the standard deviation of arc voltage and welding current, droplet transfer mode, size, and frequency, and the form and number of weld spatter occurrences. Simultaneously, the wetting angle and symmetry of the weld cross-section after welding are measured to detect the arc stability, droplet transfer behavior, and weld pool fluidity of the GSW wire. Finally, the welding process performance of the GSW wire is evaluated based on these three indicators. However, this method is complex to operate, costly to implement, involves a wide variety of equipment, and data acquisition is difficult in all spatial positions.

[0006] Chinese patent application CN201510830554.9 discloses a device and method for evaluating the stability of solid welding wire feeding. By designing a dedicated device and process for welding torch support, clamping, target application, and target evaluation, it simulates the wire feeding and welding states during actual welding, thus solving the problem of indirect evaluation of the stability of solid welding wire feeding. However, this method only reflects the stability of the welding wire's spatial position after it exits the wire, and cannot reflect the stability of the feeding and exiting processes caused by the mechanical properties of the welding wire itself. Furthermore, it also suffers from problems of complex equipment and numerous procedures.

[0007] Chinese patent application CN202311430410.5 discloses a method for evaluating the stability of welding wire feeding. This method uses a specialized device to obtain the frictional resistance during wire feeding, the center-to-center distance on a specific plane of the welding wire extension, and the eccentricity angle between the specific plane of the welding wire extension and the center of the welding torch. A quantitative correlation is then established to measure the wire feeding stability during welding. However, this method also does not consider the stability of the feeding and exiting processes caused by the mechanical properties of the welding wire itself. The evaluation method involves complex equipment and processes, resulting in high implementation costs.

[0008] In summary, currently available technical documents do not address evaluation methods for wire feeding stability and welding process stability based on the mechanical properties of the gas-shielded solid welding wire itself, nor have they found any correlations between the mechanical properties of the welding wire itself and wire feeding stability and welding process stability. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire. Based on the mechanical properties of the gas-shielded solid welding wire itself, a comprehensive factor for wire feeding stability is fitted, and a criterion for wire feeding stability and all-position welding process stability is established accordingly. This method can indirectly evaluate the stability of all-position welding processes using gas-shielded solid welding wire without the need for actual arc initiation welding.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire includes the following steps:

[0012] S1, to determine the mechanical properties of the welding wire;

[0013] S2, Obtain the elastic-plastic ratio r of the welding wire D and strain strengthening factor s D ;

[0014] S3, Constructing the comprehensive factor S for wire feeding stability WF ;

[0015] S4. Establish criteria for wire feeding stability and all-position welding process stability, and evaluate the all-position welding process stability of the welding wire to be evaluated.

[0016] Preferably, in step S1, the mechanical properties of the welding wire include the elastic limit R. P0.01 Yield limit R P0.2 Ultimate fracture strength R m and Vickers hardness HV 0.3 .

[0017] Preferably, in step S2:

[0018] The formula for calculating the elastic-plastic ratio of the welding wire is r. D =R P0.01 / R P0.2 ;

[0019] The formula for calculating the strain hardening factor is s. D =(R m -R P0.2 ) / R P0.2 ;

[0020] Where, r D R is the elastic-plastic ratio of the welding wire. P0.01 R is the elastic limit of the welding wire. P0.2 s is the yield strength of the welding wire. D R is the strain strengthening factor. m This represents the breaking strength limit of the welding wire.

[0021] Preferably, in step S3, the formula for calculating the comprehensive factor of wire feeding stability is as follows:

[0022]

[0023] In the formula, S WF Comprehensive factor for wire feeding stability, r D s is the elastic-plastic ratio of the welding wire.D HV is the strain strengthening factor. 0.3 This refers to the Vickers hardness of the welding wire.

[0024] Preferably, in step S4, the criteria for judging the wire feeding stability and the stability of the all-position welding process are as follows:

[0025] When S WF If the value is in the range of 0.7 to 1.0, the welding wire is determined to have all-position welding stability; otherwise, the welding wire does not have all-position welding stability.

[0026] This invention provides a method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire, using a comprehensive wire feeding stability factor S. WF As a criterion, it can indirectly evaluate the stability of all-position welding process of gas-shielded solid welding wire without actual arc initiation welding, and can provide technical support for the evaluation of welding material suitability, selection of welding materials, and prediction of welding quality in engineering projects; it also has the following beneficial effects:

[0027] 1. This invention does not require actual arc initiation welding; it only requires measuring a limited number of welding wire mechanical property data and utilizing the wire feeding stability comprehensive factor S. WF The criterion can indirectly and quickly predict the stability of the welding process when welding wire products are welded in all positions and in complex spatial positions, and provide technical guidance for related industrial fields. It does not require complicated equipment and devices and has the advantages of simplicity, efficiency and low cost.

[0028] 2. This invention is based on the elastic limit R. P0.01 Yield limit R P0.2 Ultimate fracture strength R m Vickers hardness HV 0.3 And the highly correlated comprehensive factor S of wire feeding stability WF The correlation between the mechanical properties of welding wire and the stability of wire feeding and welding process was established. The correlation mechanism is clear, the reproducibility is good, and the evaluation results are accurate and reliable.

[0029] 3. This invention is an indirect evaluation method for the stability of welding wire products in all-position welding process. It has universal applicability in the industry. As long as gas shielded solid welding wire is used for semi-automatic or automatic welding, this invention can be used to evaluate the welding adaptability of welding wire, screen welding materials and predict welding quality when all-position welding and welding in complex spatial positions are involved.

[0030] 4. This invention is applicable to welding manufacturing applications where the stability of the welding process is highly required due to the influence of welding position and gravity, such as all-position welding of pipelines, welding of energy medium storage tanks and spherical tanks in complex spatial positions, and vertical and overhead welding of important steel structures. It can quickly and effectively evaluate the stability of the all-position welding process of gas-shielded solid welding wire without the need for actual arc initiation welding, and provides technical guidance and reference for welding wire selection and welding quality prediction. Detailed Implementation

[0031] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with embodiments.

[0032] The present invention provides a method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire. This method uses the elastic limit, yield limit, and ultimate tensile strength of the gas-shielded solid welding wire, along with its Vickers hardness, to fit and derive a comprehensive wire feeding stability factor S. WF Based on the mechanical properties of the welding wire itself and its deformation behavior during wire feeding, as well as its influence on wire feeding stability and welding process stability, a criterion for wire feeding stability and all-position welding process stability is established. Without the need for actual arc initiation welding, the stability of all-position welding process of gas-shielded solid welding wire can be indirectly evaluated, thus providing technical reference and guidance for the evaluation of welding material suitability, screening of welding materials, and prediction of welding quality in related industrial fields.

[0033] The main technical principle underlying this invention is as follows: During the manufacturing process of gas-shielded solid welding wire, when the welding wire is coiled and wound onto a wire spool or drum, it undergoes elastic deformation and localized plastic deformation based on its own mechanical properties. Accompanying this localized plastic deformation, the welding wire exhibits a certain degree of strain intensification, which influences subsequent deformation behavior. When the welding wire is released during welding, the initial deformation is also released, and new deformation occurs under the action of the wire feeding force. The elastic deformation, localized plastic deformation, and strain intensification of the welding wire directly affect its free deformation capability, wire feeding resistance, and wire exit stability within the wire feeding hose. This influence is reflected in the wire feeding stability and welding process stability. Particularly for all-position welding of pipelines and other complex spatial welding, wire feeding stability has a greater impact on the stability of the welding process and the final weld quality. Instantaneous disturbances during the welding process can cause fluctuations in weld quality. Therefore, based on the welding wire's own elastic limit, yield strength, ultimate tensile strength, and Vickers hardness, and considering their combined influence on wire deformation and stable wire feeding, a comprehensive wire feeding stability factor S can be fitted and derived. WF Furthermore, criteria for wire feeding stability and all-position welding process stability were established to indirectly evaluate the stability of welding wire products in all-position pipeline welding and other complex spatial welding processes.

[0034] This invention discloses a method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire. First, a certain number of welding wires are cut from a wire spool or tube in a specific packaging form, and their elastic limit R is measured. P0.01 Yield limit R P0.2 Ultimate fracture strength R m and Vickers hardness HV 0.3 To ensure the reliability and accuracy of the test values, the arithmetic mean of four test values ​​was taken for each welding wire's mechanical property parameter; then, the elastic-plastic ratio r, which reflects the welding wire's elastic deformation and elastic-plastic deformation capabilities, was calculated separately. D Strain hardening factor S, which reflects the strain hardening ability of welding wire. WF As a fundamental mechanical parameter for evaluating the stability of wire feeding and the welding process, the wire feeding stability comprehensive factor S is then constructed, taking into account the wire's elastic-plastic deformation capacity, strain hardening capacity, and initial hardness. WF and establish based on S WF The stability of wire feeding and the stability criteria of all-position welding process are determined; finally, the stability of the all-position welding process is evaluated on the actual welding wire samples to be evaluated based on the wire feeding stability and the stability criteria of all-position welding process. The present invention specifically includes the following steps:

[0035] S1, to determine the mechanical properties of the welding wire;

[0036] A certain number of welding wires are cut from a welding wire spool or tube in a specific packaging form, and the mechanical properties of the welding wires are determined using the uniaxial tensile method, that is, the elastic limit R of the welding wires is determined. P0.01 Yield limit R P0.2 and ultimate fracture strength R m The Vickers hardness (HV) was measured on the longitudinal section of the welding wire. 0.3 To ensure the reliability and accuracy of the test values, the arithmetic mean of four test values ​​can be taken for each welding wire's mechanical property parameter. Here, the elastic limit R... P0.01 This represents the strength value at which 0.01% plastic strain is produced during uniaxial tension; the yield strength R. P0.2 The ultimate tensile strength R represents the strength value at which 0.2% plastic strain is generated during uniaxial tension. m HV represents the strength value corresponding to the highest load before the welding wire breaks during uniaxial tensile testing. 0.3 This indicates the Vickers hardness value measured under a load of 0.3 kg.

[0037] S2, Obtain the elastic-plastic ratio r of the welding wire D and strain strengthening factor s D ;

[0038] Elastic limit R P0.01 It characterizes the elastic deformation capacity and the size of the fully elastic range of the welding wire, and the yield strength R.P0.2 This represents the strength value of the welding wire when it has fully entered the plastic deformation range; the ratio of the two is defined as the elastic-plastic ratio r. D That is, r D =R P0.01 / R P0.2 This directly reflects the welding wire's ability to undergo fully elastic deformation and elastic-plastic deformation before entering the fully plastic range. As the level of external load increases, the welding wire enters the fully plastic deformation range and undergoes strain hardening until it reaches its ultimate fracture strength R. m Fracture subsequently occurred. The strain hardening capacity of the welding wire under external load has a significant impact on the deformation behavior, wire feeding resistance, and wire exit stability during the release process of the coiled and wound welding wire, thus affecting the stability of the welding process. The strain hardening factor s is defined. D =(R m -R P0.2 ) / R P0.2 As an important mechanical parameter that directly reflects the wire feeding process of welding wire.

[0039] S3, Constructing the comprehensive factor S for wire feeding stability WF ;

[0040] Considering the correlation between mechanical parameters such as the elastic-plastic deformation capacity, strain hardening capacity, and initial hardness of the welding wire and the wire feeding stability and all-position welding process stability, based on the aforementioned obtained elastic-plastic ratio r of the welding wire... D Strain strengthening factor s D and Vickers hardness value HV 0.3 Construct a comprehensive factor S for wire feeding stability WF :

[0041]

[0042] Comprehensive factor S for wire feeding stability WF It can comprehensively reflect the influence of the welding wire's elastic-plastic deformation capacity, strain hardening capacity, and initial hardness on wire feeding stability and all-position welding process stability.

[0043] S4. Establish criteria for wire feeding stability and all-position welding process stability, and evaluate the all-position welding process stability of the welding wire to be evaluated.

[0044] For welding wires within a certain Vickers hardness range, if the elastic-plastic ratio r D An excessively high elastic-plastic deformation ratio (r) indicates that the fully elastic deformation range of the welding wire is too large or the elastic-plastic deformation range is too narrow, which will cause excessive wire feeding resistance and is detrimental to wire feeding stability. DIf the strain intensification factor S is too low, it indicates that the elastic-plastic deformation range of the welding wire is too wide. Even under relatively small external tensile forces, deformation easily occurs, leading to significant strain intensification during the coiling and winding process. This negatively impacts the free and uniform deformation of the welding wire during subsequent wire feeding and hinders the guarantee of wire straightness and accurate delivery to the welding area. WF If the strain intensification factor S is too large, it can also easily lead to premature strain intensification during the coiling and winding process, which is detrimental to the stability of subsequent wire feeding and welding processes; if the strain intensification factor S... WF If the value is too small, the welding wire's plastic deformation capacity will be poor. The significant elastic deformation release during wire feeding will drastically increase the feeding resistance and the friction between the welding wire and the guide tube, thereby reducing the stability of the wire feeding and welding processes. Therefore, it is necessary to increase the comprehensive wire feeding stability factor S. WF The value should be controlled between 0.7 and 1.0.

[0045] For a certain number of welding wire samples to be evaluated cut from a welding wire spool or tube in a specific packaging form, without actual arc initiation welding, the relevant mechanical property parameters are determined according to the aforementioned steps, and the comprehensive factor S of wire feeding stability is calculated. WF If S WF If the value can be controlled within the range of 0.7 to 1.0, the welding wire is considered to have all-position welding stability. Otherwise, the welding wire does not have all-position welding stability.

[0046] In summary, this invention, based on the series of mechanical properties of gas-shielded solid welding wire, applies the fitted comprehensive factor S for wire feeding stability. WF As a criterion, the stability of the all-position welding process of gas-shielded solid welding wire can be indirectly evaluated without actual arc initiation welding, thus providing technical reference and guidance for the evaluation of welding material suitability, screening of welding materials, and prediction of welding quality in related industrial fields.

[0047] Example

[0048] This embodiment focuses on eight different types of gas metal arc welding wires with a diameter of 1.0 mm, and conducts an all-position welding process stability evaluation based on the mechanical properties of the gas metal arc welding wires. As mentioned above, it mainly includes the following steps:

[0049] Step 1: Determination of mechanical properties of welding wire

[0050] A certain number of welding wires were cut from a 20kg standard welding wire spool with a diameter of 300mm, and their elastic limit R was determined using the uniaxial tensile method. P0.01 Yield limit R P0.2 and ultimate fracture strength R m The Vickers hardness (HV) was measured on the longitudinal section of the welding wire. 0.3To ensure the reliability and accuracy of the test values, the arithmetic mean of four test values ​​was used for each welding wire's mechanical property parameter. Here, the elastic limit R... P0.01 This represents the strength value at which 0.01% plastic strain is produced during uniaxial tension; the yield strength R. P0.2 The ultimate tensile strength R represents the strength value at which 0.2% plastic strain is generated during uniaxial tension. m HV represents the strength value corresponding to the highest load before the welding wire breaks during uniaxial tensile testing. 0.3 This indicates the Vickers hardness value measured under a load of 0.3 kg.

[0051] Step 2: Calculation of the elastic-plastic ratio and strain hardening factor of the welding wire

[0052] Based on the aforementioned measured mechanical property parameters of the welding wire, the elastic-plastic ratio r was calculated respectively. D and strain strengthening factor s D As an important mechanical parameter that directly reflects the wire feeding process of welding wire.

[0053] Step 3: Comprehensive Factor S for Wire Feeding Stability WF calculate

[0054] Considering the correlation between mechanical parameters such as the elastic-plastic deformation capacity, strain hardening capacity, and initial hardness of the welding wire and the stability of wire feeding and all-position welding process, a comprehensive wire feeding stability factor S is calculated based on the aforementioned measured and calculated mechanical parameters. WF calculate:

[0055]

[0056] Step 4: Stability evaluation of the all-position welding process of the actual welding wire sample to be evaluated.

[0057] Based on the comprehensive factor S of wire feeding stability WF Calculated values ​​are used to evaluate the stability of the actual welding wire sample during all-position welding. If S WF If the value can be controlled within the range of 0.7 to 1.0, the welding wire is considered to have all-position welding stability. Otherwise, the welding wire does not have all-position welding stability.

[0058] Based on the above steps, the evaluation results of wire feeding stability and all-position welding process stability for eight types of welding wires are shown in Table 1.

[0059] Table 1. Evaluation results of wire feeding stability and all-position welding process stability for eight types of welding wires.

[0060]

[0061]

[0062] As shown in Table 1, welding wires 2 through 5 and welding wire 7 all meet the criteria for wire feeding stability and all-position welding process stability, and all exhibit all-position welding stability; while the comprehensive factor S for wire feeding stability of welding wires 1, 6, and 8 is... WF Since they do not meet the criteria for wire feeding stability and all-position welding process stability, welding wires 1, 6, and 8 are deemed to lack all-position welding stability.

[0063] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire, characterized in that, Includes the following steps: S1, to determine the mechanical properties of the welding wire; S2, Obtain the elastic-plastic ratio r of the welding wire D and strain strengthening factor s D ; S3, Constructing the comprehensive factor S for wire feeding stability WF ; S4. Establish criteria for wire feeding stability and all-position welding process stability, and evaluate the all-position welding process stability of the welding wire to be evaluated.

2. The method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire according to claim 1, characterized in that, In step S1, the mechanical properties of the welding wire include the elastic limit R. P0.01 Yield limit R P0.2 Ultimate fracture strength R m and Vickers hardness HV 0.3 .

3. The method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire according to claim 1, characterized in that, In step S2: The formula for calculating the elastic-plastic ratio of the welding wire is r. D =R P0.01 / R P0.2 ; The formula for calculating the strain hardening factor is s. D =(R m -R P0.2 ) / R P0.2 ; Where, r D R is the elastic-plastic ratio of the welding wire. P0.01 R is the elastic limit of the welding wire. P0.2 s represents the yield strength of the welding wire. D R is the strain strengthening factor. m This represents the breaking strength limit of the welding wire.

4. The method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire according to claim 1, characterized in that, In step S3, the formula for calculating the comprehensive factor of wire feeding stability is as follows: In the formula, S WF Comprehensive factor for wire feeding stability, r D s is the elastic-plastic ratio of the welding wire. D HV is the strain strengthening factor. 0.3 This refers to the Vickers hardness of the welding wire.

5. The method for evaluating the stability of all-position welding processes based on the mechanical properties of gas-shielded welding wire according to claim 1, characterized in that, In step S4, the criteria for judging the stability of wire feeding and the stability of the all-position welding process are as follows: When S WF If the value is in the range of 0.7 to 1.0, the welding wire is determined to have all-position welding stability; otherwise, the welding wire does not have all-position welding stability.

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