A method for establishing a high-strength austenitic stainless steel welding process characteristic curve

Abstract

The present application relates to the technical field of automatic welding, in particular to a high-strength austenitic stainless steel welding process characteristic curve making method, comprising the following specific steps: S1: selecting a welding process characteristic curve according to the parameters of corresponding ordinary stainless steel welding parts; S2: recalibrating the peak energy; S3: redeveloping the pulse waveform; S4: calculating the base current and pulse frequency based on the arc length prediction formula of the pulse parameters and the wire feeding speed. The present application adjusts and optimizes the pulse welding waveform, modifies the single pulse energy distribution of the welding process, forms a special pulse waveform for high-strength austenitic welding wire, and invents a special welding process characteristic curve customized for high-strength austenitic stainless steel welding materials, thereby optimizing the welding process and molten pool spreading property of high-strength austenitic stainless steel.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of automatic welding, in particular to a high-strength austenitic stainless steel welding process characteristic curve establishing method. BACKGROUND

[0002] Compared with the conventional GMAW, the P-GMAW has a periodic change in welding current: during the pulse peak, the peak current briefly exceeds the critical current of the spray transfer, so that the welding wire is rapidly melted to form a droplet transfer trend, and before the next droplet is formed, the current is reduced, the arc is connected by using the lower base current, and the welding wire is continuously heated. By periodically adjusting the current, the P-GMAW can realize self-controlled droplet transfer under the condition that the average welding current is lower than the critical current of the spray transfer, and the energy input of the welding process can be accurately and effectively controlled by adjusting and matching multiple pulse parameters.

[0003] However, in order to realize more accurate control of the heat input and the droplet transfer process of the welding process, the P-GMAW introduces a large number of pulse parameters, which are complex and coupled with each other. On the one hand, the flexibility of current adjustment is enhanced, but on the other hand, the learning cost of the P-GMAW is greatly increased. It is an effective way to realize the wide application of the P-GMAW to construct a special and unified welding process characteristic curve for the same type of welding wire.

[0004] The high-strength austenitic stainless steel has high strength, excellent corrosion resistance and low magnetic characteristics, and has wide application prospects in the fields of ships, nuclear power and chemical industry. Compared with ordinary 316L stainless steel, the new high-strength austenitic stainless steel has higher alloy element content and greater welding difficulty, which is mainly manifested in the problems of large welding spatter, poor molten pool spreading and difficult droplet transfer, thereby restricting its popularization and application.

[0005] The reason is that, compared with ordinary austenitic stainless steel, the new high-strength austenitic stainless steel and the matching welding material have higher alloy content, and the physical and chemical properties of the welding wire are greatly different, which is not matched with the existing welding process characteristic curve built in the welding power source. The existing welding process adjustment method can only modify the welding average current and the welding voltage on the basis of the existing welding process characteristic curve, and does not touch the essence of the pulse welding waveform, so that the pulse energy cannot be controlled, and there are problems such as large welding spatter, poor molten pool spreading and difficult side fusion, which greatly hinder the popularization and application of the high-strength austenitic stainless steel.

[0006] The welding process of super duplex stainless steel and super austenitic stainless steel disclosed in patent number CN110369837A adopts a combined welding method of TIG backing welding and GMAW-P filling and cap welding, and the process parameters such as current, voltage, welding speed and heat input in each welding procedure are optimized, so that the weld metal requirements can be ensured. However, the adjustment method of the process has a large parameter range, it is difficult to realize accurate control, and problems such as too large or too small heat-affected zone, molten pool spatter and porosity defects are prone to occur.

[0007] Therefore, it is urgent to propose a new high-strength austenitic stainless steel welding process characteristic curve development method to solve the above problems. SUMMARY

[0008] Therefore, the present application aims to provide a high-strength austenitic stainless steel welding process characteristic curve development method to solve the problems of large welding spatter, poor molten pool spreading and difficult side fusion in the existing high-strength austenitic stainless steel welding.

[0009] For P-GMAW, the energy input mainly comes from the peak stage. If you want to achieve stable one-bead-one-drop transition during the welding process, you need to match the amount of molten metal formed by each pulse, its gravity, electromagnetic necking force and surface tension. The molten metal grows stably into a spherical droplet with a diameter of 1.2 times that of the welding wire, and quickly separates from the end of the welding wire under the action of electromagnetic force and transitions downward. There is no excess molten metal trailing behind the droplet.

[0010] High-strength austenitic stainless steel wire has a higher Cr, Ni and Mn content, and its heat of fusion and molten metal viscosity are higher than those of conventional welding wire. In addition, the high Mn content also leads to a higher surface tension of the molten metal. All of these are the reasons why high-strength austenitic stainless steel wire droplet transfer is difficult.

[0011] To improve the process performance and welding efficiency of high-strength austenitic stainless steel welding materials, for high-strength austenitic stainless steel wire, starting from its physical and chemical properties, the pulse waveform parameters are optimized, the arc pressure and droplet momentum of the welding process are adjusted, and a special pulse welding current waveform is formed. Further extended to become a special welding process characteristic curve, thereby optimizing the welding process performance of high-strength austenitic stainless steel wire.

[0012] The conventional high-strength austenitic stainless steel welding process characteristic curve setting method is mostly achieved by adjusting welding current, voltage, wire feeding speed, welding speed and other parameters to realize high-strength austenitic stainless steel welding. This method can directly observe the change of welding effect by adjusting the basic welding parameters, and is simple and intuitive to operate, but the adjustment range of the basic parameters is large, it is difficult to realize accurate control, it is difficult to accurately control the heat input, it may cause the heat affected zone to be too large or too small, affect the mechanical properties of the weld, it is difficult to accurately control the stability of the molten pool, and may cause defects such as spatter and porosity.

[0013] In order to solve the above problems, the patent creatively adjusts and optimizes the pulse welding waveform, modifies the single pulse energy distribution of the welding process, forms a special pulse waveform for high-strength austenitic welding wire, and invents a special welding process characteristic curve customized for high-strength austenitic stainless steel welding material, thereby optimizing the welding process and molten pool spreading of high-strength austenitic stainless steel.

[0014] The technical scheme of the present application is implemented as follows:

[0015] The present application discloses a high-strength austenitic stainless steel welding process characteristic curve setting method, comprising the following specific steps:

[0016] S1: selecting an initial welding process characteristic curve; selecting a welding process characteristic curve according to the parameters of the corresponding ordinary stainless steel welding piece as the initial reference;

[0017] S2: recalibrating the peak energy; recalibrating the peak energy according to the characteristics of high-strength austenitic stainless steel to ensure reasonable distribution of energy in the welding process;

[0018] S3: redeveloping the pulse waveform; redeveloping the pulse waveform according to the material properties and welding requirements of high-strength austenitic stainless steel to optimize the heat input and molten pool stability in the welding process;

[0019] S4: calculating the base current and pulse frequency based on the arc length prediction formula of the pulse parameters and wire feeding speed.

[0020] Further, in step S1, the parameters of the welding piece include thickness, geometric shape, joint type, weld position and wire diameter.

[0021] Further, in step S2, calibrating the peak energy includes determining the optimal peak current and peak time, selecting a series of peak currents and peak times within the welding current range based on the selected wire feeding speed and high-strength austenitic welding wire, and testing by orthogonal test method to determine the optimal peak current and peak time.

[0022] Further, the peak current test range is 300A-500A, the adjusting step is 20A, the peak time range is 1.2ms-2.7ms, the step is 0.1ms, the peak current is 320-360A, and the peak time is 2.2-2.4ms in the stable transition range, which is the optimal pulse parameter range.

[0023] Further, in step S2, the judgment standard of the optimal peak current and peak time is that the droplet is separated from the pulse and the droplet is crisp.

[0024] Further, in step S3, the pulse waveform is selected as a rectangular wave, and the peak time is the peak time in step S2.

[0025] Further, in step S4, the arc length prediction formula based on the pulse parameters and the wire feeding speed is

[0026] R 2 =0.9857

[0027] L=-12.22596+0.01552*I B +0.0354*I P +5.21194*t p -0.02577*f -0.97645*V

[0028] wherein: L is the arc length;

[0029] I B is the base current, unit: A;

[0030] I P is the peak current, unit: A;

[0031] t p is the peak time, unit: ms;

[0032] f is the pulse frequency, unit: Hz;

[0033] V is the wire feeding speed, unit: m / min.

[0034] Further, in step S4, the calculation steps of the base current and the pulse frequency are:

[0035] S41: determine the wire diameter and the wire feeding speed range;

[0036] S42: uniformly select multiple feature points in the wire feeding speed range;

[0037] S43: set the welding arc length, peak current and peak time of each feature point;

[0038] S44: The base value current and pulse frequency of each feature point are matched by means of the P-GMAW arc length prediction formula, and the overall welding process feature curve is obtained.

[0039] Further, when a 1.0 mm diameter solid core welding wire is selected, the wire feeding speed working range is 5-15 m / min, six feature points are uniformly selected in the range, the welding arc length of each feature point is set to 7 mm, the peak current is fixed to 340 A, the peak time is 2.3 ms, the base value current and pulse frequency of each feature point are matched by means of the P-GMAW arc length prediction formula, and the overall welding process feature curve is obtained.

[0040] Further, it further comprises the step S5 of verifying and optimizing the welding process feature curve, the applicability of the feature curve and the welding quality are verified through actual welding test, and the welding parameters are further optimized according to the test result.

[0041] Compared with the prior art, the high-strength austenitic stainless steel welding process feature curve preparation method has the following advantages:

[0042] The present application solves the problem that the adjustment range of basic parameters is large and accurate control is difficult to realize in the conventional preparation method by adjusting and optimizing the pulse welding waveform, modifying the single pulse energy distribution of the welding process, forming a special pulse waveform for high-strength austenitic welding wire, and avoiding the problems of large welding spatter, poor molten pool spreading, and difficult side fusion in the welding process of high-strength austenitic stainless steel.

[0043] The present application invents a special welding process feature curve for high-strength austenitic stainless steel welding material through creative experiment, and further optimizes the welding process and molten pool spreading of high-strength austenitic stainless steel, reduces the learning cost of welding operators, and is helpful for the popularization and application of high-strength austenitic stainless steel. DETAILED DESCRIPTION

[0044] The accompanying drawings, which form a part of the present application, are used to provide a further understanding of the present application, and the illustrative embodiments thereof and their descriptions serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0045] Figure 1 It is the peak energy calibration record of the present application;

[0046] Figure 2 It is the original pulse waveform comparison chart of the present application;

[0047] Figure 3 It is the molten drop transition state chart of the rectangular waveform of the present application;

[0048] Figure 4 It is the molten drop transition state chart of the exponential waveform of the present application;

[0049] Figure 5 Typical pulse waveform diagram before optimization of the present application;

[0050] Figure 6 Droplet transfer process diagram after optimization of the present application;

[0051] Figure 7 Weld bead cross section comparison diagram before and after adjustment of the present application, (a) is using original pulse waveform (b) is using optimized waveform;

[0052] Figure 8 Arc length predicted value and measured value comparison diagram of the present application;

[0053] Figure 9 Droplet transfer state diagram of each feature point of the present application;

[0054] Figure 10 Welding spatter collection method diagram of the present application;

[0055] Figure 11 Welding spatter comparison diagram of the present application;

[0056] Figure 12 Spatter weight comparison diagram of the present application;

[0057] Figure 13 Original feature curve welding process electrical signal recording diagram of the present application;

[0058] Figure 14 Optimized feature curve welding process electrical signal recording diagram of the present application;

[0059] Figure 15 U-I phase diagram comparison of the present application, (a) is using G3Si1 feature curve, (b) is using optimized process feature curve diagram;

[0060] Figure 16 Butt joint test plate welding appearance comparison of the present application (a) (c) is using G3Si1 feature curve butt joint bead appearance, (b) (d) is using optimized feature curve butt joint bead appearance diagram;

[0061] Figure 17 Corner joint bead appearance comparison of the present application (a) is using G3Si1 feature curve corner joint bead appearance, (b) is using optimized feature curve corner joint bead appearance diagram;

[0062] Figure 18 Corner joint bead appearance comparison of the present application (a) is using G3Si1 feature curve corner joint bead appearance, (b) is using optimized feature curve corner joint bead appearance diagram. DETAILED DESCRIPTION

[0063] In order to make the technical means and purposes of the present application easy to understand, the embodiments of the present application are described in detail below in combination with specific drawings.

[0064] It should be noted that all the terms indicating direction and position in the present application, such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inner", "outer", "top", "low", "transverse", "longitudinal", "center", etc., are only used to explain the relative position relationship, connection condition, etc. between components in a certain specific state, and are only for the convenience of describing the present application, and thus cannot be understood as a limitation on the present application. In addition, the description of "first", "second", etc. in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features.

[0065] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected, can be mechanical connection, can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0066] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The welding process characteristic curve is a chart drawn by experimental data, which shows the relationship between various parameters in the welding process and the welding result.

[0068] In pulse welding, the welding current is obtained by calculation.

[0069] The application discloses a method for formulating a welding process characteristic curve of high-strength austenitic stainless steel.

[0070] S1: selecting an initial welding process characteristic curve; selecting a welding process characteristic curve according to the parameters of a corresponding ordinary stainless steel welded part as an initial reference;

[0071] S2: Re-calibrate the peak energy; according to the characteristics of high-strength austenitic stainless steel, re-calibrate the peak energy to ensure reasonable distribution of energy during welding;

[0072] S3: Re-form the pulse waveform; according to the material characteristics of high-strength austenitic stainless steel and welding requirements, re-form the pulse waveform to optimize heat input and molten pool stability during welding;

[0073] S4: Calculate the base current and pulse frequency based on the arc length prediction formula of pulse parameters and wire feed speed.

[0074] According to the parameter selection of the corresponding ordinary stainless steel welding piece, the welding process characteristic curve is selected as an initial welding process characteristic curve as a starting point, providing a reference for subsequent optimization and adjustment; through re-calibration of peak energy and formulation of pulse waveform, better weld formation can be achieved, reducing the unevenness and undercutting of the weld, ensuring full penetration of the weld, reducing incomplete penetration and slag inclusion and other welding defects, better molten pool control and weld formation, reducing spatter and porosity and other welding defects; using the arc length prediction formula, according to the pulse parameters and wire feed speed, the appropriate base current and pulse frequency are calculated to ensure the stability of the arc and the controllability of the welding process.

[0075] This setting realizes the optimization of welding parameters by re-calibrating the peak energy, formulating the pulse waveform and calculating the base current and pulse frequency, which can improve the welding quality, production efficiency and reduce welding defects, has strong pertinence, systematicness and scientificity, and solves the problems of difficult droplet transfer of high-strength austenitic stainless steel welding wire, uncontrollable pulse energy, large welding spatter, poor molten pool spreadability, and difficult side fusion during pulse gas tungsten arc welding of high-strength austenitic stainless steel.

[0076] Specifically, in step S1, the parameters of the welding piece include thickness, geometry, joint type, weld position and wire diameter.

[0077] By comprehensively considering the thickness, geometry, joint type, weld position and wire diameter of the welding piece, the welding parameters of the same structure ordinary stainless steel welding piece can be selected, ensuring that the selection of welding parameters is more reasonable, guaranteeing the welding quality, production efficiency and reducing welding defects, providing a basic welding parameter setting for subsequent tests, facilitating the optimization and adjustment.

[0078] This setting can effectively reduce the number of subsequent tests, which helps to reduce the test cost.

[0079] Specifically, in step S2, calibrating the peak energy includes determining the optimal peak current and peak time, and selecting a series of peak currents and peak times in the welding current range based on the selected wire feeding speed and high-strength austenitic stainless steel wire diameter, and testing the optimal peak current and peak time by using the orthogonal test method.

[0080] The peak current and peak time are determined by various test combinations, which can better control the shape and fluidity of the molten pool, realize the smooth forming of the weld, reduce the unevenness, undercut phenomenon, incomplete penetration, cracks and slag inclusion and other welding defects of the weld, ensure the uniformity and aesthetics of the weld, and solve the problem of difficult droplet transfer of high-strength austenitic stainless steel welding wire.

[0081] The setting ensures that the selected peak current and peak time have scientific basis through welding tests and data recording, improves the rationality and accuracy of the welding parameters, guarantees the welding quality of high-strength austenitic stainless steel, and improves the welding efficiency.

[0082] Specifically, taking 11 m / min as the reference wire feeding speed, the peak current test range is 300 A-500 A, the adjustment step is 20 A, the peak time is tested from low to high, and the step is 0.1 ms. The optimal transition and upper and lower boundaries are selected comprehensively in the stable transition range, the peak current is 320-360 A, and the peak time is 2.2-2.4 ms, which is the optimal pulse parameter range.

[0083] The setting determines the optimal peak current and peak time of high-strength austenitic stainless steel at the reference wire feeding speed of 11 m / min, reduces the labor intensity of recalibrating the peak energy of high-strength austenitic stainless steel at this wire feeding speed, and is helpful for subsequent formation of the welding process characteristic curve.

[0084] Specifically, in step S2, the judgment standard of the optimal peak current and peak time is that the droplet is one pulse and one drop, and the separation is crisp.

[0085] The droplet is one pulse and one drop, and the separation is crisp, which can ensure the stable transfer of the droplet, reduce the generation of spatter and pores, make the weld uniform, and reduce the unevenness, undercut phenomenon and cracks of the weld.

[0086] The setting can effectively improve the forming quality of the weld, reduce welding defects, ensure the mechanical properties of the weld, shorten the welding time, and improve the production efficiency.

[0087] Specifically, in step S3, the pulse waveform is selected as a rectangular wave, and the peak time is the peak time in step S2.

[0088] The steep rising and falling edges of the rectangular wave can achieve fast droplet transfer, reduce the time of molten droplets in the air, thereby reducing spatter, the high peak current of the rectangular wave can provide sufficient energy to ensure sufficient penetration of the weld, reduce welding defects such as incomplete penetration and slag inclusion, and the short peak time of the rectangular wave can effectively control the welding heat input, reduce welding deformation and hardness of the heat affected zone.

[0089] The setting can ensure the stability of the arc and the controllability of the welding process, reduce fluctuations in the welding process, reduce welding defects, shorten the welding time, improve the welding speed and quality, and improve the production efficiency.

[0090] Specifically, in step S3, for a typical wire feeding speed of 11 m / min, the peak time is increased to 2.3 ms and the peak current is adjusted to 350 A based on the original rectangular waveform, and the average value of the fusion width is increased from 8.15 mm to 8.92 mm.

[0091] For a typical wire feeding speed of 11 m / min, the droplet transfer process of the rectangular pulse waveform and the exponential pulse waveform is compared, and because the liquid metal viscosity of the high-strength austenitic welding wire is large, the rectangular wave can better promote the droplet detachment;

[0092] Therefore, based on the original rectangular waveform, the peak time is increased to 2.3 ms and the peak current is adjusted to 350 A, and the droplet transfer state is greatly improved, and the waveform and transition state are shown in FIG. 5 and FIG. 6. At the same time, the extension of the pulse time increases the action time of the arc on the molten pool, promotes the spreading of the molten pool, and the average value of the fusion width is increased from 8.15 mm to 8.92 mm.

[0093] In step S3, for a typical wire feeding speed of 11 m / min, the peak time is increased to 2.3 ms and the peak current is adjusted to 350 A based on the original rectangular waveform, and the average value of the fusion width is increased from 8.15 mm to 8.92 mm, which can optimize the droplet transfer, improve the penetration quality, improve the weld formation, reduce the welding defects and improve the welding stability, and can ensure that the selection of welding parameters is more reasonable, improve the welding quality and production efficiency.

[0094] Specifically, in step S4, the arc length prediction formula based on the pulse parameters and the wire feeding speed is

[0095] R 2 =0.9857

[0096] L=-12.22596+0.01552*I B +0.0354*I P +5.21194*t p -0.02577*f -0.97645*V

[0097] wherein: L is the arc length;

[0098] I B is the base current, unit: A;

[0099] I P is the peak current, unit: A;

[0100] t p is the peak time, unit: ms;

[0101] f is the pulse frequency, unit: Hz;

[0102] V is the wire feed speed, unit: m / min.

[0103] R 2 = 0.9857 represents the determination coefficient, which measures the fitting degree of the model, that is, the proportion of the variation explained by the model in the total variation, R 2 the value of which ranges from 0 to 1, the closer the value to 1, the better the fitting degree of the model. R 2 = 0.9857 indicates that the model can explain about 98.57% of the data variation, which is a very high value, indicating that the model is very well fitted to the data.

[0104] The setting can accurately control the base current and pulse frequency through the arc length prediction formula, ensure the stability of the arc and the controllability of the welding process, reduce the fluctuations in the welding process, ensure the consistency and repeatability of the welding process, and improve the welding quality and production efficiency.

[0105] Specifically, in step S4, the calculation steps of the base current and the pulse frequency are:

[0106] S41: determine the wire diameter and the wire feed speed range;

[0107] S42: uniformly select multiple feature points in the wire feed speed range;

[0108] S43: set the welding arc length, peak current, and peak time of each feature point;

[0109] S44: match the base current and the pulse frequency of each feature point by means of the P-GMAW arc length prediction formula, and then obtain the overall welding process characteristic curve.

[0110] In step S4, by determining the welding wire diameter and the wire feeding speed range, a plurality of characteristic points are uniformly selected, the welding arc length, the peak current and the peak time of each characteristic point are set, the base current and the pulse frequency of each characteristic point are matched by means of the P-GMAW arc length prediction formula, and then the overall welding process characteristic curve is obtained, so that the welding parameters can be better optimized, the welding quality can be improved and the welding defects can be reduced, and the stability of the welding process and the quality of the weld can be ensured.

[0111] The base current and the pulse frequency are obtained by calculating by means of the arc length formula, a large number of tests are avoided, the test cost is reduced, the exclusive welding process characteristic curve is formed, the subsequent welding use is facilitated, the consistency of the welding process and the welding quality are ensured, and the learning cost is reduced.

[0112] Preferably, when the 1.0 mm diameter solid core welding wire is selected, the wire feeding speed working range is 5-15 m / min, 6 characteristic points are uniformly selected in the range, the welding arc length of each characteristic point is set to 7 mm, the peak current is fixed to 340 A, the peak time is 2.3 ms, the base current and the pulse frequency of each characteristic point are matched by means of the P-GMAW arc length prediction formula, and the overall welding process characteristic curve obtained is shown in Table 1. The base current and the pulse frequency increase linearly with the increase of the wire feeding speed, the peak parameter remains unchanged, the droplet transfer state under the parameters is shown in Figure 9 The stable and crisp one-droplet-one-arc transition is realized in the wire working range, the droplet overheating explosion and short circuit phenomenon are basically eliminated, and the welding spatter rate is greatly reduced.

[0113] Table 1 Process characteristic point parameters

[0114]

[0115] When the wire feeding speed changes, the most intuitive influence of the mismatch between the wire melting speed and the wire feeding speed is the change of the welding arc length. The welding arc length is closely related to the welding quality. Under the same liquid bridge length, the droplet will contact the molten pool before it is separated under a shorter arc length, which will further cause short circuit. Under an excessively long arc length, side wall arc will be caused in the groove, and arc drift and other phenomena will occur. For plate surfacing, the ideal arc length is about 7 mm.

[0116] The setting forms the high-strength austenitic stainless steel welding process characteristic curve of the 1.0 mm diameter welding wire, which is helpful to ensure the welding quality, facilitate direct reference in the subsequent processing process, improve the consistency of the welding process, and reduce the welding quality difference.

[0117] Specifically, it further includes step S5: verifying and optimizing the welding process characteristic curve, verifying the applicability of the characteristic curve and the welding quality through actual welding test, and further optimizing the welding parameters according to the test results.

[0118] This setting ensures that the final welding process characteristic curve can meet the needs of practical applications, helping to improve welding quality and production efficiency.

[0119] Example 1

[0120] Select 1.0 mm high-strength austenitic stainless steel welding wire, wire feed speed is 11 m / min, peak current is 320-360 A, peak time is 2.2-2.4 ms, and square wave is selected for pulse waveform.

[0121] For 1.0 mm diameter solid core welding wire, the working range of wire feed speed is 5-15 m / min, 6 characteristic points are uniformly selected in this range, the welding arc length of each characteristic point is set to 7 mm, the peak current is fixed at 340 A, the peak time is 2.3 ms, and the base current and pulse frequency of each characteristic point are matched by means of P-GMAW arc length prediction formula. The obtained overall welding process characteristic curve is shown in Table 1. The base current and pulse frequency increase linearly with the increase of wire feed speed, and the peak parameter remains unchanged. The droplet transfer state under this set of parameters is shown in Figure 9 The stable and crisp one-droplet-one-arc transition is achieved in the wire working range, and the droplet overheating explosion and short circuit phenomenon is basically eliminated, and the welding spatter rate is greatly reduced.

[0122] Example 2

[0123] The obtained special process characteristic curve and the process curve provided by the welding machine are compared in terms of welding spatter rate, welding stability and weld appearance.

[0124] (1) Comparison of welding spatter rate

[0125] First, the welding spatter of single-pass welding of the plate is collected and weighed for comparison, and the collection method is shown in Figure 10 Two pieces of red copper plate are placed on both sides of the weld, the bottom distance is 16 mm, the top distance is 100 mm, the weld length is controlled to be 250 mm, the welding speed is 30 cm / min, and the spatter particles on the copper plate are scraped off after welding for weighing. Figure 10 shows the welding spatter collection method

[0126] The G3Si1 characteristic curve provided by the welding machine and the optimized process characteristic curve are used for welding 3 times, and the obtained spatter weight comparison is shown in Figures 11 and 12, the spatter weight is reduced by 83.04%,

[0127] Figure 11 shows the comparison of welding spatter, and Figure 12 shows the comparison of spatter weight

[0128] (2) Comparison of welding stability

[0129] The arc welding quality analyzer is used to collect current and voltage data of the welding process during the welding process, the current standard deviation of the welding process using the original characteristic curve is 214.53, and the variation coefficient is 1.14422; the current standard deviation of the welding process using the high-strength austenitic welding wire process characteristic curve is 106.97, and the variation coefficient is 0.70781. The obtained data is plotted in a U-I phase diagram; Figures 13 to 15 As shown, the welding process using the optimized process characteristic curve is more stable, and there is no short circuit, arc breaking and the like. Figure 13 is an electric signal record of the welding process using the original characteristic curve; Figure 14 is an electric signal record of the welding process using the optimized characteristic curve; Figure 15 is a U-I phase diagram comparison, (a) is using G3Si1 characteristic curve, and (b) is using the optimized process characteristic curve.

[0130] (3) Comparison of weld appearance

[0131] The weld appearance using G3Si1 characteristic curve and the weld appearance using the high-strength austenitic welding wire characteristic curve are compared, as shown in Figures 16 to 18 It can be seen that the customized process characteristic curve significantly improves the weld pool spreading of the A700 welding wire welding, significantly improves the problem of side wall incomplete fusion in the welding of the V-shaped groove, and forms a uniform and full weld. Figure 16 is a comparison of the welding appearance of the butt joint test plate, (a) and (c) are the welding appearance of the butt joint using G3Si1 characteristic curve, (b) and (d) are the welding appearance of the butt joint using the optimized characteristic curve; Figure 17 is a comparison of the welding appearance of the corner joint, (a) is the welding appearance of the corner joint using G3Si1 characteristic curve, (b) is the welding appearance of the corner joint using the optimized characteristic curve, Figure 18 is a comparison of the welding appearance of the corner joint, (a) is the welding appearance of the corner joint using G3Si1 characteristic curve, and (b) is the welding appearance of the corner joint using the optimized characteristic curve.

[0132] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of developing a high-strength austenitic stainless steel welding process profile, characterized by, The method comprises the following specific steps: S1: selecting an initial welding process characteristic curve; selecting a welding process characteristic curve corresponding to the parameters of a common stainless steel welding part as an initial reference; S2: recalibrating the peak energy; recalibrating the peak energy according to the characteristics of the high-strength austenitic stainless steel to ensure reasonable energy distribution in the welding process; S3: redeveloping the pulse waveform; According to the material characteristics and welding requirements of the high-strength austenitic stainless steel, the pulse waveform is redeveloped to optimize the heat input and molten pool stability in the welding process; S4: calculating the base current and pulse frequency based on the arc length prediction formula of the pulse parameters and the wire feeding speed; In step S4, the arc length prediction formula based on the pulse parameters and the wire feeding speed is R 2 ＝0.9857 L = -12.22596 + 0.01552*IB + 0.0354*IP + 5.21194*tp - 0.02577*f - 0.97645*V Wherein: L is the arc length; IB is the base current, unit: A; IP is the peak current, unit: A; tp is the peak time, unit: ms; f is the pulse frequency, unit: Hz; V is the wire feeding speed, unit: m / min; R 2 = 0.9857 represents the coefficient of determination, which measures the degree of fitting of the model.

2. The method for determining the welding process characteristic curve of high-strength austenitic stainless steel according to claim 1, characterized in that, In step S1, the parameters of the welding part include thickness, geometric shape, joint type, weld position and wire diameter.

3. The method for determining the characteristic curve of high-strength austenitic stainless steel welding process according to claim 1, characterized in that, In step S2, calibrating the peak energy includes determining the optimal peak current and peak time, taking the selected wire feeding speed and high-strength austenitic welding wire as the basis, selecting a series of peak currents and peak times within the welding current range, testing by orthogonal test method to determine the optimal peak current and peak time.

4. The method for determining the characteristic curve of high-strength austenitic stainless steel welding process according to claim 3, characterized in that, Taking 11 m / min as the reference wire feeding speed, the peak current test range is 300A-500A, the adjustment step is 20A, the peak time range is 1.2ms-2.7ms, the step is 0.1ms, within the stable transition range, the peak current is 320-360A, and the peak time is 2.2-2.4ms, which is the optimal pulse parameter range.

5. The method for determining the welding process characteristic curve of high-strength austenitic stainless steel according to claim 3, characterized in that, In step S2, the judgment standard of the optimal peak current and peak time is that the droplet-pulse-droplet is separated crisp.

6. The method of claim 1, wherein the HAGS welding process profile is characterized by, In step S3, the pulse waveform is selected as a rectangular wave, and the peak time is the peak time in step S2.

7. The method for determining the characteristic curve of high-strength austenitic stainless steel welding process according to claim 1, characterized in that, In step S4, the calculation steps of the base current and pulse frequency: S41: determining the wire diameter and wire feeding speed range; S42: uniformly selecting multiple characteristic points within the wire feeding speed range; S43: setting the welding arc length, peak current and peak time of each characteristic point; S44: matching the base current and pulse frequency of each characteristic point by means of the arc length prediction formula, and then obtaining the overall welding process characteristic curve.

8. The method for determining the characteristic curve of high-strength austenitic stainless steel welding process according to claim 7, characterized in that, When a 1.0mm diameter solid core welding wire is selected, the working range of the wire feeding speed is 5-15m / min, 6 characteristic points are uniformly selected within this range, the welding arc length of each characteristic point is set to 7mm, the peak current is fixed to 340A, the peak time is 2.3ms, the base current and pulse frequency of each characteristic point are matched by means of the arc length prediction formula, and the overall welding process characteristic curve is obtained.

9. The method of claim 1 to 8, c h a ra cte ri zed i n that It also includes step S5: verifying and optimizing the welding process characteristic curve, verifying the applicability of the characteristic curve and the welding quality through actual welding test, and further optimizing the welding parameters according to the test results.

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