焊缝余高变异系数在水下湿法焊接质量评估过程中的应用

Study on the application of the weld reinforcement variation coefficient in underwater wet welding quality evaluation

关键词:  水下湿法焊接|焊接质量|焊缝余高|变异系数

Key words:  underwater wet welding|welding quality|weld reinforcement|variation coefficient

摘要:

针对水下湿法焊接质量评定中缺乏简便、客观的评价指标的现状，提出利用焊缝余高的变异系数表征焊接质量. 该指标具有支持定量分析客观性强、步骤简单易操作等优点. 余高变异系数越大，焊缝外观成形均匀性越差，焊接质量越低；反之，焊缝越平滑、美观，焊接质量越好. 为验证该指标的准确性，设计了相关的工艺试验. 依据脉冲电流对焊接过程稳定性的影响，开展不同脉冲频率条件下焊接. 鉴于送丝方式对焊接过程影响较大，利用焊缝余高变异系数分析送丝方式对水下湿法药芯焊丝焊接过程稳定性研究. 结果表明，余高变异系数评价结果与焊接质量相关度较高. 焊接过程中采用X射线高速成像技术，从焊接过程稳定性与熔滴过渡类型等方面深入分析了焊接过程对余高变异系数的影响，进一步验证了该指标的可靠性.

Abstract:

There is a lack of an evaluation index which can assess the appearance of welds user-friendly and accurately in underwater wet welding. To solve this problem, the weld reinforcement variation coefficient is proposed to be used for evaluating the welding quality. The evaluation index has many advantages such as objective, quantitative, less step and easy operation, which is suitable for popularization and application in practical engineering production. The weld reinforcement variation coefficient grows higher with the worse the uniformity of weld appearance and the lower the welding quality and vice versa. According to the influence of pulse current on the stability of welding process, welding was carried out under different pulse frequency conditions. In view of the influence of wire feeding method on welding process, the stability of underwater wet flux-cored wire welding process was studied by analyzing the wire feeding method with the coefficient of variation of residual high welding seam. The experimental results show that the evaluation results of the index have high consistency with welding quality. The influences of the welding process on the weld reinforcement variation coefficient are analyzed using an X-ray transmission method. The reliability of the weld reinforcement variation coefficient is further verified by researching the welding electrical signal and droplet transfer.