7020鋁合金焊接工藝對焊接殘余應力與應變的影響研究

關鍵詞：7020鋁合金；焊接仿真；預熱；熱源輸入；殘余應力應變

中圖分類號：TH162 文獻標志碼：A 文章編號：1003-5168(2025)11-0024-04

DOI:10.19968/j.cnki.hnkj.1003-5168.2025.11.006

Research on the Influence of 7O2O Aluminum Alloy Welding Process on WeldingResidualStressandStrain

ZHANG Huayan (Shanghai-Donghu MachineryFactory，Shanghai2O19oo，China)

Abstract: [Purposes] This study aims to investigate the effects of different welding process parameters on residual stress and residual strain in the welding repair of 7O2O aluminum alloy plates， with the goal of determining optimal heat input parameters to optimize welding quality.[Methods]A welding simulation model based on the double-elipsoidal heat source model was established using inert gas-shielded laser welding technology.Finite element analysis was employed to simulate the dynamic thermo一 mechanical coupling process. Multiple experimental parameters，including welding current ( 200～240 （20 A)， voltage ( 20～24 V)，and initial workpiece temperature (20～300^°C )，were examinedto analyze their effects on temperature distribution，residual stress，and residual strain.[Findings] The simulation results indicate that when the welding current was 240 A and the voltage was 24 V，both residual stress and strain were minimized.When the preheating temperature is 200^°C ，the residual stress and strain can be significantly reduced，but when the temperature rises to 300^° C， the residual strain increases instead. Additionally，the increase in power leads toa rise in the maximum temperature，but hasa limited impacton residual stress.[Conclusions] The optimized welding parameters (240 A current，24 V voltage) combined with 200^°C preheating effectively controlled residual stress and strain，providing a theoretical basisfor the welding repair process of 7O2O aluminum alloy plates. Keywords: 7O2O aluminum aloy; welding simulation; preheating; heat sourse input; residual stress-strain

0 引言

焊接變形與殘余應力形成機理的研究發現，鋁合金焊接過程中的熱-力耦合效應是引發焊接部位變形與殘余應力的關鍵因素。馬嘉恒等1通過6系鋁合金焊接試驗與有限元仿真，發現焊接部位上翹變形與局部殘余應力分布密切相關，高能量輸入導致非均勻熱膨脹與收縮，引發塑性應變積累。崔倫赫在6005A中空薄壁鋁合金的動態熱-力耦合模型中進一步驗證了這一機制，其通過基于熱-彈-塑性法的仿真表明，盡管熱影響區(HAZ)較窄，但焊縫附近殘余應力顯著高于母材。孫建通等3通過X射線衍射與有限元計算，發現Al- ?Mg-Mn 合金激光焊接中橫向應力集中于焊縫兩端的壓應力區，縱向應力表現為焊縫中心的拉應力分布，揭示了多向應力疊加的復雜性。

而熱輸入參數對焊接質量影響的研究指出，焊接工藝參數的優化是控制殘余應力的核心手段之一。呂成4針對船用鋁合金的Fluent多物理場模擬表明，焊接速度直接影響熔池形貌與溫度場分布，具體為速度過低易導致熱積累引發變形，速度過高則可能產生未熔合缺陷，需通過動態平衡確定最佳參數。楊少紅等5在船用5083鋁合金接頭研究中發現，焊接電流與殘余應力呈正相關，電流增大導致熱輸入增加，焊縫區冷卻收縮加劇，縱向殘余應力峰值升高。這提示操作人員必須在熔深需求與應力控制間尋求平衡。……