碎丝埋弧焊工艺在钢桥制造中的应用研究

为有效提高钢桥制造的焊接工效,减少其焊接变形,降低制造成本,针对钢桥制造中的焊接接头形式,研究碎丝埋弧焊工艺。介绍了碎丝埋弧焊的原理及特点,分析了碎丝埋弧焊常见焊接缺陷类型及其产生原因,提出了其避免措施;进一步讨论了该工艺在实际生产中的适应性情况,并由此提出了可行的解决方案。结果表明,在采用合理的焊接工艺条件下,焊接接头性能符合各项规范指标要求,能有效提高焊接工效,减少焊接变形。

Parametric optimization of friction stir welding process of age hardenable aluminum alloys-ANFIS modeling

A comparative approach was performed between the response surface method(RSM) and the adaptive neuro-fuzzy inference system(ANFIS) to enhance the tensile properties, including the ultimate tensile strength and the tensile elongation, of friction stir welded age hardenable AA6061 and AA2024 aluminum alloys. The effects of the welding parameters, namely the tool rotational speed, welding speed, axial load and pin profile, on the ultimate tensile strength and the tensile elongation were analyzed using a three-level, four-factor Box-Behnken experimental design. The developed design was utilized to train the ANFIS models. The predictive capabilities of RSM and ANFIS were compared based on the root mean square error, the mean absolute error, and the correlation coefficient based on the obtained data set. The results demonstrate that the developed ANFIS models are more effective than the RSM model.

国内大口径、高钢级管道焊接及焊缝检测技术现状

针对国内大口径、高钢级管道普遍采用半自动焊技术而逐渐暴露的焊接质量问题,研究了大口径、高钢级管道的焊接技术及焊缝检测技术。分析了半自动焊与全自动焊对大口径、高钢级管道环焊缝质量的影响因素,并通过西气东输高钢级管道焊口泄漏事故失效分析报告、管材低温冲击试验与金相分析报告及环焊缝焊接工艺试验,验证了影响焊接质量的因素;开展了半自动焊与全自动焊经济性对比,得到了焊接机组成本与完成工作量的关系;研究了自动超声波检测技术的可靠性,提出了国内全自动焊焊缝检测的方法。由此可得:对于大口径、高钢级管道,全自动焊能够有效避免半自动焊环焊缝低温冲击功值偏低且离散的问题,具有质量可靠、工效提升的优势,但从经济性角度考虑,只有当全自动焊工作量大于经济焊接工作量时,全自动焊的经济效益才会超过半自动焊;全自动焊焊缝质量可采用自动超声波检测技术检验。因此,建议在大口径、高钢级管道的建设施工中,全面推行全自动焊技术。