Ultra-low-speed argon arc welding deformation inhibition process for high-nitrogen steel sheet

Abstract

The invention relates to the technical field of welding, and discloses a deformation restraining process for ultra-low-speed argon arc welding of a high-nitrogen steel sheet. According to the deformation restraining technology for the ultra-low-speed argon arc welding of the high-nitrogen steel sheet, the flow of the protective gas is dynamically regulated and controlled based on the change of the arc pressure in the welding process so as to restrain the non-uniform oxidation rate of a molten pool; the welding temperature field is analyzed in real time, the welding gun swing path is adjusted to improve the structure uniformity, the welding current slope is adjusted in a self-adaptive mode to prevent incomplete root fusion according to welding temperature field feedback and the molten pool form change trend, and according to the molten pool surface tension change characteristic and the welding current slope adjusting result, the welding temperature field is adjusted in real time. And the arc length is subjected to closed-loop regulation and control to optimize the welding seam forming quality. According to the deformation restraining process for the ultra-low-speed argon arc welding of the high-nitrogen steel sheet, the problem that the welding seam quality fluctuates due to the uneven oxidation rate of a molten pool is effectively solved, and the consistency of the welding seam quality is guaranteed.

Description

Technical Field

[0001] This application relates to the field of welding technology, and in particular to a deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates. Background Technology

[0002] This article focuses on the deformation suppression process of ultra-low speed argon arc welding of high-nitrogen steel thin plates. The core is to reduce the structural deformation caused by uneven expansion and contraction of the heat-affected zone during welding by accurately controlling the welding parameters and process flow, thereby improving the weld formation quality and material properties.

[0003] However, this process faces many key technical challenges in practice: for example, how to dynamically adjust the shielding gas flow rate based on changes in arc pressure to control the oxidation rate of the molten pool; how to optimize the welding torch oscillation path based on real-time feedback from the temperature field to prevent local overheating and uneven microstructure; how to adaptively adjust the welding current slope in conjunction with changes in penetration depth to avoid root fusion problems; how to control the arc length in a closed loop based on changes in molten pool surface tension to improve metal transition and weld formation; in addition, it is also necessary to consider how to precisely control the temperature gradient of post-weld heat treatment to address differences in cooling rates and prevent uneven phase precipitation from affecting the mechanical properties of high-nitrogen steel. Summary of the Invention

[0004] To address the problems mentioned in the background art, this application provides a deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates.

[0005] This application provides a deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates, employing the following technical solution:

[0006] A deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates includes:

[0007] Step 1: Dynamically regulate the shielding gas flow rate based on changes in arc pressure during welding to suppress uneven oxidation rate of the molten pool;

[0008] Step 2: Based on the molten pool morphology information after adjusting the shielding gas flow rate, analyze the welding temperature field in real time and adjust the welding torch oscillation path to improve the uniformity of the microstructure.

[0009] Step 3: Based on the feedback of the welding temperature field and the changing trend of the molten pool morphology, adaptively adjust the slope of the welding current to prevent root fusion failure;

[0010] Step 4: Based on the surface tension variation characteristics of the molten pool and the adjustment results of the welding current slope, the arc length is controlled in a closed loop to optimize the weld formation quality.

[0011] Preferably, the dynamic regulation of shielding gas flow rate based on changes in arc pressure during welding further includes:

[0012] Obtain the arc pressure value P monitored in real time during the welding process;

[0013] Calculate the target protective gas flow rate Q = K * (P / P0)C, where K is the proportional coefficient, P0 is the reference arc pressure, and C is the compensation constant;

[0014] If Q is greater than the preset maximum value Q_max, then Q = Q_max; otherwise, keep the calculation result.

[0015] If P is lower than the set lower limit P_min, the emergency replenishment mechanism for protective gas is activated.

[0016] Preferably, the real-time analysis of the welding temperature field based on the molten pool morphology information after adjusting the shielding gas flow rate further includes:

[0017] Acquire a thermal image of the current welding area and extract the coordinates (x, y) of the center point of the high-temperature area;

[0018] The temperature distribution is fitted using the formula T(x,y)=A*e^{B(x^2+y^2)}, where A is the maximum temperature coefficient and B is the diffusion coefficient.

[0019] Determine whether the peak temperature exceeds the threshold T_threshold;

[0020] Adjust the welding torch oscillation amplitude according to the temperature distribution uniformity, so that it is positioned at the boundary of the molten pool to reduce the impact of temperature difference.

[0021] Preferably, the adaptive adjustment of the welding current slope based on the welding temperature field feedback and the changing trend of the molten pool morphology further includes:

[0022] Monitor the rate of change of weld penetration depth dD / dt and compare it with the preset target rate of change D_target;

[0023] Adjust the current slope ΔI / Δt = K1*ΔD+K2 according to the deviation ΔD=dD / dtD_target;

[0024] If the value of ΔI / Δt exceeds the set maximum value I_limit, then it is limited to not exceed I_limit;

[0025] Adjust the direction of the current slope based on the trend of molten pool width variation W_trend to ensure molten penetration stability.

[0026] Preferably, the closed-loop control of the arc length based on the surface tension variation characteristics of the molten pool and the adjustment result of the welding current slope further includes:

[0027] The relationship curve between the surface tension coefficient σ(t) of the molten pool and time t was measured;

[0028] Calculate the linear regression relationship between arc voltage V_arc and wire feed speed f_wire;

[0029] The arc length is determined based on the surface tension change rate dσ / dt. If dσ / dt>α, ΔL=β*(σ(t)σ_ref) is executed, where β is the control sensitivity and σ_ref is the standard surface tension.

[0030] The welding torch height is dynamically adjusted through a feedback loop to maintain the stability of the molten pool and the quality of the weld formation.

[0031] Preferably, the dynamic control of the shielding gas flow rate based on changes in arc pressure during welding further includes:

[0032] The initial current fluctuation ΔI0 was detected during the welding initiation stage;

[0033] Establish the curve showing the relationship between the protective gas flow rate Q and ΔI0: Q(ΔI0) = α*ΔI0^2 + β*ΔI0 + γ;

[0034] The ΔI0 value is calculated in real time during the welding process, and the optimized setting value of Q is obtained by looking up the table;

[0035] Once the welding is stable, Q is stabilized at Q_stable to reduce gas fluctuations caused by frequent adjustments.

[0036] Preferably, the step of finely controlling the welding torch oscillation path based on real-time feedback from the welding temperature field further includes:

[0037] Temperature gradient zones are divided based on thermal imaging data to determine high and low temperature regions;

[0038] The local superheat level is quantified by the parameter τ_thermal=T_max / (T_avg*t_rate), where T_max is the maximum temperature, T_avg is the average temperature, and t_rate is the time rate of increase.

[0039] Small-amplitude oscillation (A_low) and high-frequency control are implemented in the low-temperature region to avoid overcooling;

[0040] Large-amplitude swing (A_high) and low-frequency control are used in high-temperature areas to enhance the uniformity of the molten pool.

[0041] Preferably, the adaptive adjustment of the welding current slope based on the weld penetration variation trend further includes:

[0042] The weld penetration depth D and root fusion condition are analyzed using a visual inspection system.

[0043] The trend of melt depth variation is defined as S_trend=(D_nD_{n1}) / dt. If S_trend<ΔD_crit, it means that the root may not be fused.

[0044] When S_trend is less than ΔD_crit, the current slope enhancement strategy is activated: ΔI / Δt=max(ΔI_base,ΔI_base+K3*|S_trend|);

[0045] Determine whether multiple welding repairs are needed based on the root shape detected in real time.

[0046] Preferably, the closed-loop control of the arc length based on the surface tension variation characteristics of the molten pool further includes:

[0047] Calculate the edge tension distribution function of the molten pool σ(r) = σ_0 + ω*r + κ*r^2, where σ_0 is the basic tension, ω is the curvature coefficient, and κ is the edge perturbation parameter;

[0048] The degree of matching between the molten pool radius r_p and the tension change rate dσ / dr is detected to determine the arc stability;

[0049] If dσ / dr > ε_r and r_p exceeds the safety threshold R_safe, then execute ΔL = μ*(dσ / drε_r), where μ is the correction coefficient;

[0050] The corrected ΔL is fed back to the arc control module in real time to ensure the continuity of molding.

[0051] Preferably, the precise control of the post-weld heat treatment temperature gradient based on the difference in cooling rates of the welded joints further includes:

[0052] The temperature decay curve after welding was recorded using an infrared thermometer, and the cooling rate V_cool at each point was calculated.

[0053] A temperature field model is established to express the cooling gradient δT = T_startT_final, which is used to assess the tissue evolution trend.

[0054] Define the control parameter K_therm=λ*V_cool+η to control the temperature rise slope of post-weld heat treatment;

[0055] Different heat treatment temperature ranges are set according to K_therm partitions to make the crystal phase precipitation in each part more uniform and improve the material strength.

[0056] The precise control of the post-weld heat treatment temperature gradient based on the difference in cooling rates of the welded joints further includes:

[0057] Introduce a cooling rate threshold V_cool_threshold and compare it with the measured cooling rate V_cool;

[0058] Use a conditional statement: if V_cool > V_cool_threshold: execute the fast heat treatment procedure; else: execute the slow equalization procedure to ensure that the fast-cooling part is controlled first.

[0059] The gradient heating rate is set according to the phase transformation temperature of the metal at different locations after welding;

[0060] By combining the hardness test data after cooling, a closed-loop feedback mechanism is established to optimize subsequent heat treatment strategies.

[0061] In summary, this application includes at least one of the following beneficial technical effects:

[0062] 1. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates effectively solves the problem of weld quality fluctuation caused by uneven oxidation rate of molten pool by dynamically adjusting the protective gas flow rate based on arc pressure changes, thus ensuring the consistency of weld quality.

[0063] 2. The deformation suppression process of ultra-low speed argon arc welding of high nitrogen steel thin plate analyzes the welding temperature field in real time based on the molten pool morphology information after the shielding gas flow rate is adjusted, and adjusts the welding torch oscillation path to improve the problem of reduced microstructure uniformity caused by local overheating, making the weld microstructure more uniform.

[0064] 3. The deformation suppression process of ultra-low speed argon arc welding of high-nitrogen steel thin plate adaptively adjusts the welding current slope according to the feedback of welding temperature field and the trend of molten pool morphology, which prevents root non-fusion caused by heat concentration and improves the integrity of the welded joint.

[0065] 4. The deformation suppression process of ultra-low speed argon arc welding of high-nitrogen steel thin plate is based on the surface tension change characteristics of the molten pool and the adjustment results of the welding current slope. The arc length is controlled in a closed loop, which solves the problem of weld formation defects caused by discontinuous metal transition and makes the weld formation better. Attached Figure Description

[0066] Figure 1 A flowchart of a deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates. Detailed Implementation

[0067] The embodiments of this application are described in detail below, and examples of the embodiments are shown in the accompanying drawings.

[0068] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0069] This application discloses a deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates, referring to... Figure 1 ,include:

[0070] Step 1: Dynamically regulate the shielding gas flow rate based on changes in arc pressure during welding to suppress uneven oxidation rate of the molten pool;

[0071] Step 2: Based on the molten pool morphology information after adjusting the shielding gas flow rate, analyze the welding temperature field in real time and adjust the welding torch oscillation path to improve the uniformity of the microstructure.

[0072] Step 3: Based on the feedback of the welding temperature field and the changing trend of the molten pool morphology, adaptively adjust the slope of the welding current to prevent root fusion failure;

[0073] Step 4: Based on the surface tension variation characteristics of the molten pool and the adjustment results of the welding current slope, the arc length is controlled in a closed loop to optimize the weld formation quality.

[0074] Dynamic regulation of shielding gas flow based on changes in arc pressure during welding further includes:

[0075] Obtain the arc pressure value P monitored in real time during the welding process;

[0076] Calculate the target protective gas flow rate Q = K * (P / P0)C, where K is the proportional coefficient, P0 is the reference arc pressure, and C is the compensation constant;

[0077] If Q is greater than the preset maximum value Q_max, then Q = Q_max; otherwise, keep the calculation result.

[0078] If P is lower than the set lower limit P_min, the emergency replenishment mechanism for protective gas is activated.

[0079] Real-time analysis of the welding temperature field based on the molten pool morphology information after shielding gas flow rate adjustment further includes:

[0080] Acquire a thermal image of the current welding area and extract the coordinates (x, y) of the center point of the high-temperature area;

[0081] The temperature distribution is fitted using the formula T(x,y)=A*e^{B(x^2+y^2)}, where A is the maximum temperature coefficient and B is the diffusion coefficient.

[0082] Determine whether the peak temperature exceeds the threshold T_threshold;

[0083] Adjust the welding torch oscillation amplitude according to the temperature distribution uniformity, so that it is positioned at the boundary of the molten pool to reduce the impact of temperature difference.

[0084] The adaptive adjustment of the welding current slope based on welding temperature field feedback and molten pool morphology trends further includes:

[0085] Monitor the rate of change of weld penetration depth dD / dt and compare it with the preset target rate of change D_target;

[0086] Adjust the current slope ΔI / Δt = K1*ΔD+K2 according to the deviation ΔD=dD / dtD_target;

[0087] If the value of ΔI / Δt exceeds the set maximum value I_limit, then it is limited to not exceed I_limit;

[0088] Adjust the direction of the current slope based on the trend of molten pool width variation W_trend to ensure molten penetration stability.

[0089] The closed-loop control of the arc length based on the surface tension variation characteristics of the molten pool and the adjustment results of the welding current slope further includes:

[0090] The relationship curve between the surface tension coefficient σ(t) of the molten pool and time t was measured;

[0091] Calculate the linear regression relationship between arc voltage V_arc and wire feed speed f_wire;

[0092] The arc length is determined based on the surface tension change rate dσ / dt. If dσ / dt>α, ΔL=β*(σ(t)σ_ref) is executed, where β is the control sensitivity and σ_ref is the standard surface tension.

[0093] The welding torch height is dynamically adjusted through a feedback loop to maintain the stability of the molten pool and the quality of the weld formation.

[0094] Dynamically controlling the shielding gas flow rate based on changes in arc pressure during welding further includes:

[0095] The initial current fluctuation ΔI0 was detected during the welding initiation stage;

[0096] Establish the curve showing the relationship between the protective gas flow rate Q and ΔI0: Q(ΔI0) = α*ΔI0^2 + β*ΔI0 + γ;

[0097] The ΔI0 value is calculated in real time during the welding process, and the optimized setting value of Q is obtained by looking up the table;

[0098] Once the welding is stable, Q is stabilized at Q_stable to reduce gas fluctuations caused by frequent adjustments.

[0099] Further fine-tuning of the welding torch oscillation path based on real-time feedback from the welding temperature field includes:

[0100] Temperature gradient zones are divided based on thermal imaging data to determine high and low temperature regions;

[0101] The local superheat level is quantified by the parameter τ_thermal=T_max / (T_avg*t_rate), where T_max is the maximum temperature, T_avg is the average temperature, and t_rate is the time rate of increase.

[0102] Small-amplitude oscillation (A_low) and high-frequency control are implemented in the low-temperature region to avoid overcooling;

[0103] Large-amplitude swing (A_high) and low-frequency control are used in high-temperature areas to enhance the uniformity of the molten pool.

[0104] The adaptive adjustment of the welding current slope based on the trend of weld penetration depth further includes:

[0105] The weld penetration depth D and root fusion condition are analyzed using a visual inspection system.

[0106] The trend of melt depth variation is defined as S_trend=(D_nD_{n1}) / dt. If S_trend<ΔD_crit, it means that the root may not be fused.

[0107] When S_trend is less than ΔD_crit, the current slope enhancement strategy is activated: ΔI / Δt=max(ΔI_base,ΔI_base+K3*|S_trend|);

[0108] Determine whether multiple welding repairs are needed based on the root shape detected in real time.

[0109] Closed-loop control of arc length based on the surface tension variation characteristics of the molten pool further includes:

[0110] Calculate the edge tension distribution function of the molten pool σ(r) = σ_0 + ω*r + κ*r^2, where σ_0 is the basic tension, ω is the curvature coefficient, and κ is the edge perturbation parameter;

[0111] The degree of matching between the molten pool radius r_p and the tension change rate dσ / dr is detected to determine the arc stability;

[0112] If dσ / dr > ε_r and r_p exceeds the safety threshold R_safe, then execute ΔL = μ*(dσ / drε_r), where μ is the correction coefficient;

[0113] The corrected ΔL is fed back to the arc control module in real time to ensure the continuity of molding.

[0114] Precise control of the post-weld heat treatment temperature gradient based on the difference in cooling rates of the welded joints further includes:

[0115] The temperature decay curve after welding was recorded using an infrared thermometer, and the cooling rate V_cool at each point was calculated.

[0116] A temperature field model is established to express the cooling gradient δT = T_startT_final, which is used to assess the tissue evolution trend.

[0117] Define the control parameter K_therm=λ*V_cool+η to control the temperature rise slope of post-weld heat treatment;

[0118] Different heat treatment temperature ranges are set according to K_therm partitions to make the crystal phase precipitation in each part more uniform and improve the material strength.

[0119] The precise control of the post-weld heat treatment temperature gradient based on the difference in cooling rates of the welded joints further includes:

[0120] Introduce a cooling rate threshold V_cool_threshold and compare it with the measured cooling rate V_cool;

[0121] Use a conditional statement: if V_cool > V_cool_threshold: execute the fast heat treatment procedure; else: execute the slow equalization procedure to ensure that the fast-cooling part is controlled first.

[0122] The gradient heating rate is set according to the phase transformation temperature of the metal at different locations after welding;

[0123] By combining the hardness test data after cooling, a closed-loop feedback mechanism is established to optimize subsequent heat treatment strategies.

[0124] The present invention discloses a deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates, comprising: real-time acquisition of data on arc pressure, molten pool morphology, temperature field distribution, surface tension, and penetration depth changes during the welding process through an integrated sensing system, and dynamic adjustment of welding parameters by combining intelligent control algorithms. This process synergistically optimizes the welding process from five aspects, effectively improving the quality stability and forming consistency of ultra-low speed argon arc welding of high-nitrogen steel thin plates.

[0125] First, the shielding gas flow rate is dynamically controlled based on changes in arc pressure during welding. By detecting arc pressure fluctuations, the system can quickly respond and adjust the inert gas (such as argon) flow rate to maintain a suitable gas shielding effect. This control strategy helps suppress uneven oxygen intrusion rates on the molten pool surface, prevents intensified oxidation reactions, thereby reducing the uneven distribution of the oxide layer on the weld surface and lowering the risk of weld quality fluctuations.

[0126] Secondly, by analyzing real-time feedback information of the welding temperature field, the welding torch is dynamically oscillated along a preset path, resulting in more uniform heating of the molten pool. This control measure effectively alleviates the microstructure segregation problem caused by local overheating, and improves the microstructure uniformity and mechanical properties of the welded joint.

[0127] Third, dynamically adjusting the welding current slope based on the trend of penetration depth can prevent root fusion failure due to heat concentration. This adaptive current adjustment method enhances the controllability of energy input during welding and improves weld formation quality.

[0128] Fourth, the arc length is controlled in a closed loop based on the surface tension variation characteristics of the molten pool to achieve continuity and stability of metal transition, thereby reducing the probability of weld formation defects.

[0129] Fifth, based on the difference in cooling rates of the welded joints, the temperature gradient of the post-weld heat treatment is precisely controlled to ensure a uniform and orderly phase transformation process, preventing uneven phase precipitation in high-nitrogen steel during post-weld heat treatment, thereby improving the overall mechanical properties of the weld. In summary, this invention provides a set of efficient, precise, and stable welding control methods, significantly improving the welding quality and reliability of high-nitrogen steel thin plates.

[0130] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates, characterized in that, include: Step 1: Dynamically regulate the shielding gas flow rate based on changes in arc pressure during welding to suppress uneven oxidation rate of the molten pool; Step 2: Based on the molten pool morphology information after adjusting the shielding gas flow rate, analyze the welding temperature field in real time and adjust the welding torch oscillation path to improve the uniformity of the microstructure. Step 3: Based on the feedback of the welding temperature field and the changing trend of the molten pool morphology, adaptively adjust the slope of the welding current to prevent root fusion failure; Step 4: Based on the surface tension variation characteristics of the molten pool and the adjustment results of the welding current slope, the arc length is controlled in a closed loop to optimize the weld formation quality.

2. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 1, characterized in that, The dynamic regulation of shielding gas flow rate based on changes in arc pressure during welding further includes: Obtain the arc pressure value P monitored in real time during the welding process; Calculate the target protective gas flow rate Q = K * (P / P0)C, where K is the proportional coefficient, P0 is the reference arc pressure, and C is the compensation constant; If Q is greater than the preset maximum value Q_max, then Q = Q_max; otherwise, keep the calculation result. If P is lower than the set lower limit P_min, the emergency replenishment mechanism for protective gas is activated.

3. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 2, characterized in that, The real-time analysis of the welding temperature field based on the molten pool morphology information after adjusting the shielding gas flow rate further includes: Acquire a thermal image of the current welding area and extract the coordinates (x, y) of the center point of the high-temperature area; The temperature distribution is fitted using the formula T(x,y)=A*e^{B(x^2+y^2)}, where A is the maximum temperature coefficient and B is the diffusion coefficient. Determine whether the peak temperature exceeds the threshold T_threshold; Adjust the welding torch oscillation amplitude according to the temperature distribution uniformity, so that it is positioned at the boundary of the molten pool to reduce the impact of temperature difference.

4. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 3, characterized in that, The adaptive adjustment of the welding current slope based on welding temperature field feedback and molten pool morphology trend further includes: Monitor the rate of change of weld penetration depth dD / dt and compare it with the preset target rate of change D_target; Adjust the current slope ΔI / Δt = K1*ΔD+K2 according to the deviation ΔD=dD / dtD_target; If the value of ΔI / Δt exceeds the set maximum value I_limit, then it is limited to not exceed I_limit; Adjust the direction of the current slope based on the trend of molten pool width variation W_trend to ensure molten penetration stability.

5. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 4, characterized in that, The closed-loop control of the arc length based on the surface tension variation characteristics of the molten pool and the adjustment results of the welding current slope further includes: The relationship curve between the surface tension coefficient σ(t) of the molten pool and time t was measured; Calculate the linear regression relationship between arc voltage V_arc and wire feed speed f_wire; The arc length is determined based on the surface tension change rate dσ / dt. If dσ / dt>α, ΔL=β*(σ(t)σ_ref) is executed, where β is the control sensitivity and σ_ref is the standard surface tension. The welding torch height is dynamically adjusted through a feedback loop to maintain the stability of the molten pool and the quality of the weld formation.

6. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 5, characterized in that, The dynamic control of shielding gas flow rate based on changes in arc pressure during welding further includes: The initial current fluctuation ΔI0 was detected during the welding initiation stage; Establish the curve showing the relationship between the protective gas flow rate Q and ΔI0: Q(ΔI0) = α*ΔI0^2 + β*ΔI0 + γ; The ΔI0 value is calculated in real time during the welding process, and the optimized setting value of Q is obtained by looking up the table; Once the welding is stable, Q is stabilized at Q_stable to reduce gas fluctuations caused by frequent adjustments.

7. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 6, characterized in that, The precise control of the welding torch oscillation path based on real-time feedback from the welding temperature field further includes: Temperature gradient zones are divided based on thermal imaging data to determine high and low temperature regions; The local superheat level is quantified by the parameter τ_thermal=T_max / (T_avg*t_rate), where T_max is the maximum temperature, T_avg is the average temperature, and t_rate is the time rate of increase. Small-amplitude oscillation (A_low) and high-frequency control are implemented in the low-temperature region to avoid overcooling; Large-amplitude swing (A_high) and low-frequency control are used in high-temperature areas to enhance the uniformity of the molten pool.

8. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 7, characterized in that, The adaptive adjustment of the welding current slope based on the weld penetration depth variation trend further includes: The weld penetration depth D and root fusion condition are analyzed using a visual inspection system. The trend of melt depth variation is defined as S_trend=(D_nD_{n1}) / dt. If S_trend<ΔD_crit, it means that the root may not be fused. When S_trend is less than ΔD_crit, the current slope enhancement strategy is activated: ΔI / Δt=max(ΔI_base,ΔI_base+K3*|S_trend|); Determine whether multiple welding repairs are needed based on the root shape detected in real time.

9. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 8, characterized in that, The closed-loop control of the arc length based on the surface tension variation characteristics of the molten pool further includes: Calculate the edge tension distribution function of the molten pool σ(r) = σ_0 + ω*r + κ*r^2, where σ_0 is the basic tension, ω is the curvature coefficient, and κ is the edge perturbation parameter; The degree of matching between the molten pool radius r_p and the tension change rate dσ / dr is detected to determine the arc stability; If dσ / dr > ε_r and r_p exceeds the safety threshold R_safe, then execute ΔL = μ*(dσ / drε_r), where μ is the correction coefficient; The corrected ΔL is fed back to the arc control module in real time to ensure the continuity of molding.

10. The deformation suppression process for ultra-low speed argon arc welding of high-nitrogen steel thin plates according to claim 9, characterized in that, The precise control of the post-weld heat treatment temperature gradient based on the difference in cooling rates of the welded joints further includes: The temperature decay curve after welding was recorded using an infrared thermometer, and the cooling rate V_cool at each point was calculated. A temperature field model is established to express the cooling gradient δT = T_startT_final, which is used to assess the tissue evolution trend. Define the control parameter K_therm=λ*V_cool+η to control the temperature rise slope of post-weld heat treatment; Different heat treatment temperature ranges are set according to K_therm partitions to make the crystal phase precipitation in each part more uniform and improve the material strength. The precise control of the post-weld heat treatment temperature gradient based on the difference in cooling rates of the welded joints further includes: Introduce a cooling rate threshold V_cool_threshold and compare it with the measured cooling rate V_cool; Use a conditional statement: if V_cool > V_cool_threshold: execute the fast heat treatment procedure; else: execute the slow equalization procedure to ensure that the fast-cooling part is controlled first. The gradient heating rate is set according to the phase transformation temperature of the metal at different locations after welding; By combining the hardness test data after cooling, a closed-loop feedback mechanism is established to optimize subsequent heat treatment strategies.

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