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文章编号: 1672-6987(2025)02-0098-09 DOI: 10.16351/j.1672-6987.2025.02.014
于长海1, 周方正1, 朱克明2, 贾传宝1*, 周卫鲁1, 李佳鹏1(1. 山东大学 材料液固结构演变与加工教育部重点实验室, 山东 济南 250061;2. 中核检修有限公司北方分公司, 山东 青岛 266400)
摘要: 作为一种高能量密度的电弧焊接方法,穿孔等离子弧焊接能够在不开坡口条件下对中厚度金属材料实现一次焊透,在焊接加工领域中具有重要的应用价值和推广潜力。然而,由于液态熔池沿板厚方向呈不均匀分布,小孔和熔池的受力条件较为复杂。随着板厚的增大,小孔难以维持稳定状态,焊接难度成倍增长。本研究针对大熔深穿孔等离子弧焊接时存在的熔池液态金属震荡剧烈且易塌陷等一系列关键问题,提出一种新颖的受控恒定穿孔等离子弧焊接工艺,克服了传统受控脉冲波形对大厚度工件焊接的不适用问题。提出自适应尾焰电压阈值,并与实时尾焰电压值比较,用以判断小孔的大小状态。采用焊接电流为控制量,调整速度快,调整幅度小,减弱电弧密度变化对液态金属造成的冲击影响。在该控制策略下,小孔始终处于开启状态且尺寸基本恒定,进而提高焊接过程的稳定性。受控恒定穿孔等离子弧焊接工艺的提出,避免熔池异常状态带来的焊接缺陷问题,实现了大熔深条件下的稳定穿孔焊接,一定程度上扩展了穿孔等离子弧焊接方法在相关行业的应用范围。
关键词: 等离子弧焊接; 受控恒定穿孔; 自适应控制; 尾焰电压; 大熔深
中图分类号: TG 456.2 文献标志码: A
引用格式: 于长海, 周方正, 朱克明, 等. 基于受控恒定穿孔策略的大熔深等离子弧焊接新工艺[J]. 青岛科技大学学报(自然科学版), 2025, 46(2): 98-106.
YU Changhai, ZHOU Fangzheng, ZHU Keming, et al. A novel welding process for deep penetration plasma arc welding based on controlled constant keyholing strategy[J]. Journal of Qingdao University of Science and Technology(Natural Science Edition), 2025, 46(2): 98-106.
A Novel Welding Process for Deep Penetration Plasma Arc Welding Based on Controlled Constant Keyholing Strategy
YU Changhai1, ZHOU Fangzheng1, ZHU Keming2, JIA Chuanbao1, ZHOU Weilu1, LI Jiapeng1
(1. Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, China;2. North Branch of China Nuclear Power Maintenance Co., Ltd., Qingdao 266400, China)
Abstract: As a high-energy-density arc welding method, keyhole plasma arc welding (K-PAW) can achieve single-pass full penetration of medium-thickness metal materials without opening the groove, and has important application value and promotion potential in the field of welding processing. However, due to the non-uniform distribution of the liquid molten pool along the plate thickness direction, the stress conditions of the keyhole and the molten pool are more complicated. As the thickness of work pieces increasing, it is difficult for keyhole to maintain the quasi-stable status, and the difficulty of welding increases exponentially. Aiming at a series of key problems such as violent vibration and collapse of the liquid metal in the molten pool during deep penetration keyhole plasma arc welding, this study proposes a novel controlled constant penetration welding process, which overcomes the traditional controlled pulse waveform is not applicable to the welding of large thickness workpieces. The adaptive efflux plasma arc voltage threshold is proposed, and compared with the real-time efflux voltage value, it is used to judge the keyhole size and status. The welding current is used as the control source, with the fast adjustment speed and the small range, so that the impact of the arc density change on the liquid metal is weakened. In the case of this control strategy, the keyhole is always opened and its size is basically constant, improving the stability of the welding process. The proposal of controlled constant penetration plasma arc welding process avoids the welding defect problem caused by the abnormal status of the molten pool, realizes the quasi-stable status welding under the condition of deep penetration, and expands the K-PAW method in related industries to a certain extent scope of application.
Key words: plasma arc welding; controlled constant penetration; adaptive control; efflux plasma arc voltage; deep penetration
收稿日期: 2024-06-01
基金项目: 国家自然科学基金项目(52405388,51975332).
作者简介: 于长海(1978—),男,硕士研究生. * 通信联系人.