Optimization of back bead geometry in the PMAG-TIG twin arc hybrid root welding process using grey based Taguchi method

This study investigated multi-response optimization of the pulse metal active gas-tungsten inert gas( PMAG-TIG) twin arc hybrid root welding process for an optimal parametric combination to yield favorable back bead geometry of welded joints using grey relational analysis and Taguchi method.Eighteen experimental runs based on an orthogonal array following the Taguchi method were performed to derive objective functions to be optimized within the experimental domain.The objective functions were selected in relation to parameters of PMAG-TIG twin arc root welding back bead geometry: back bead width to root reinforcement ratio and deposited metal height.The Taguchi approach was followed by grey relational analysis to solve the multi-response optimization problem.The significance of factors on overall quality characteristics of the weld joint was also evaluated quantitatively using analysis of variance.Optimal results were verified through additional experiments,and showed to feasibility of applying grey relation analysis in combination with Taguchi technique for continuous improvement of product quality in the manufacturing industry.

STT焊接技术在俄罗斯远东管道中的应用

针对俄罗斯东西伯利亚-远东太平洋管道通过高纬度、严寒地区的特点,详细介绍了管道STT焊接技术的工艺特点,重点阐述了焊接参数的调节方式,通过试验并结合现场实践经验,得出了适合低温环境下STT根焊的工艺参数。

管件环缝根焊道铜垫成形法焊接实验

文章介绍了小口径管件环缝根焊道铜垫成形法。叙述了试验用的设备构造、几种焊接方法的选择,影响根焊道质量的因素等。结果表明:这种方法与常用的"手工单面焊双面成形法"或"STT单面焊双面成形法"相比,具有焊接速度快、焊缝合格率高、劳动强度低。

X80管线钢低氢焊条根焊技术

目前我国大直径长输管道大部分采用X80管线钢,X80钢根焊道的焊接常采用管道全位置自动焊、STT和RMD半自动焊、钨极氩弧焊以及焊条电弧焊等工艺。管道全位置自动焊设备昂贵、适应性差。STT和RMD半自动焊焊接时灵活性较差,必须严格防风措施。钨极氩弧焊的抗风能力差且焊接效率太低。低氢焊条电弧焊虽操作难度大且焊接效率不高,但灵活性强、焊接接头力学性能好且设备简单,适应于返修、连头和不良地段的焊接。详细介绍了X80管线钢低氢焊条根焊焊道的焊前准备、焊接操作技术及焊接工艺参数。