药芯焊丝CO2单面焊接工艺的研究

从强制成形单面焊基本过程及其特点出发，叙述了强制成形单面焊的实现条件及陶瓷村垫药芯焊丝CO2气体保护单面焊工艺要点；根据药芯焊丝CO2气体保护焊电弧特征及单面焊工艺过程特点．通过工艺试验，分析和讨论了主要焊接参数和焊接工艺因素对陶瓷衬垫药芯焊丝CO2气体保护单面焊工艺过程及背面焊缝成形质量的影响。     

水下湿法焊接药芯焊丝成分设计及焊接工艺研究进展

对水下湿法药芯焊丝焊接的研究成果与发展现状进行了详尽的综述,介绍了水下湿法药芯焊丝焊接的优点、药芯成分的设计、工艺特点和接头性能,并提出了目前水下湿法药芯焊丝焊接存在的问题及今后的发展方向。水下湿法药芯焊丝焊接时,高氢含量、高压力和较快的冷却速度影响焊接接头的质量,而通过调整药芯焊丝的材料成分配比和在药芯中添加合金元素,可以实现渣气联合保护,达到优化焊缝组织性能的目的,也可以通过调整焊接工艺参数来优化焊缝。水下湿法药芯焊丝焊接技术的出现,使得水下焊接向高效、自动化的方向发展。     

不锈钢药芯焊丝E308LT1-1对防飞溅剂的适应性改进

通过对不锈钢药芯焊丝E308LT1-1在使用防飞溅剂时,焊接后容易产生气孔进行分析,发现防飞溅剂污染焊接坡口后焊接时产生了大量的气体,导致不锈钢药芯焊丝E308LT1-1焊缝容易产生氢气孔。合理控制氟化物和氧化物的加入量能够提高不锈钢药芯焊丝对防飞溅剂的适应性,使焊缝不产生气孔;合理加入氧化铁和氧化铈不会对该药芯焊丝工艺性能和力学性能产生不良影响。     

X70管道自保护药芯焊丝环焊接头力学性能及影响因素

采用ER70S-G STT根焊与E551T8-K2自保护药芯焊丝进行热焊、填充和盖面焊接了X70管道环焊缝,测试并统计了环焊接头的力学性能,分析了影响力学性能的主要因素。结果表明,X70管道自保护药芯焊丝环焊接头具有较好的力学性能,影响其力学性能的主要因素是焊缝中的夹渣、气孔和未熔合等焊接缺陷;并指出焊接缺陷不仅与自保护药芯焊接的自身工艺特点有关,更重要的是与焊接操作水平和质量意识密切相关。     

Al对药芯焊丝CO_2气体保护焊焊缝质量的影响

通过改变药芯焊丝中Al元素含量,获得了一系列CO_2气体保护焊焊缝。基于对焊缝中气孔和夹杂的分析以及力学性能测试,分析了铝对药芯焊丝CO_2气体保护焊焊缝质量的影响。试验结果表明,当焊丝中Al元素含量增加时,焊缝气孔敏感性降低;夹杂数量减少但夹杂体积增大;焊缝强度随Al含量提高先减小后增大,而韧性先增大后减小;当焊丝中Al元素含量为0.48%(质量分数)时,焊缝气孔较少且夹杂较少,焊缝力学性能良好。     

药芯焊丝CO2气体保护焊厚板碳素钢的焊接裂纹分析

国内某大型发电机配套设备制造厂生产机座、端盖、出线盒等低碳、低合金结构钢厚壁构件.这些构件原制造过程中采用焊条电弧焊和埋弧焊工艺,考虑到药芯焊丝CO2气体保护焊工艺生产效率高、工艺性能和焊接质量好等特点,改为采用药芯焊丝CO2气体保护焊工艺焊接这些厚壁产品.在用药芯焊丝CO2气体保护焊工艺焊接的部分厚板构件焊缝在焊后和消应力退火后超声波探伤发现焊缝中存在裂纹,裂纹大致为横向.     

小规格自保护药芯焊丝E71T-11的研制

从渣系配比、工艺性等方面介绍一种小规格自保护药芯焊丝E71T-11的研制过程。采用典型的Ba F2-Al2O3-Mg O渣系,焊接时无需气体保护,依靠药芯中的各类氟化物消除氢气孔,利用药芯中的铝固定空气中的氮以防止氮气孔的产生,该焊丝一般用于全位置单层或多层焊接,焊接板厚不大于19 mm;通过对比分析证明,焊丝具有良好的焊接工艺性。经过大量试验,研制出了符合美标要求的E71T-11自保护药芯焊丝。     

管线钢用自保护药芯焊丝气孔敏感性研究

气孔敏感性是研究自保护药芯焊丝的关键。为改善自保护药芯焊丝的气孔敏感性,以Ba F2-Fe2O3-Al-Mg渣系自保护药芯焊丝为研究对象,通过气孔敏感性试验,研究了药芯组分对气孔的影响。研究结果表明:过高的残余Al恶化韧性。低温韧性与夹杂物的尺寸、残余Al含量、微合金化元素含量、焊缝中残余O与N含量等均有关系,最佳的O含量范围为:合理控制焊缝各微量元素含量可有效提高熔敷金属低温韧性。     

自保护药芯焊丝熔化速度模型及其影响因素

焊丝熔化速度与送进速度的合理匹配是保征焊接过程稳定和获得良好焊缝成形质量的基础。在焊接过程稳定的条件下,通过采集电弧电压、焊接电流、焊丝伸出长度等工艺信息,定量分析和研究了焊丝伸出长度和焊接电流对自保护药芯焊丝熔化速度的影响规律,同时求出了焊丝熔化速度模型系数。研究结果为采用自保护药芯焊丝的钢轨窄间隙电弧焊的工艺规范制定和参数匹配提供了理论指导和依据。     

钛型渣系气保护药芯焊丝研究进展

从药芯焊丝的电弧形态和熔滴过渡形态以及影响因素、焊丝的发展和改进等方面,综述了钛型渣系气保护药芯焊丝研究的某些进展.结果表明,药芯焊丝熔滴过渡的基本形态是非轴向排斥过渡,焊丝的电弧形态属于活动、连续型,焊丝熔滴过渡受主导力控制.影响气保护药芯焊丝熔滴过渡的主要因素有:药芯组成物、焊丝截面形状、焊丝直径和钢带厚度、焊接工艺参数等.提出了通过熔滴过渡指数控制焊接飞溅和通过电弧中熔滴吸收氢的总质量控制焊缝中气孔(压坑)的新思路.焊丝内在质量关键技术是熔敷金属韧性稳定性的控制,必须重视焊丝生产线装备的技术先进性因素.     

Alternative current flux zoned tungsten inert gas welding process for aluminium alloys

Abstract

A new variant of activating flux tungsten inert gas (TIG) welding process called flux zoned TIG (FZ-TIG) welding is proposed to weld aluminium alloys based on the mechanism of activating flux constricting welding arc. This process can not only increase weld penetration but also obtain perfect weld surface appearance simultaneously. An alternative current FZ-TIG welding is made using SiO₂ as the side region material and flux FZ108 developed by the authors with uniform design method as the central region coat material. The weld penetration can reach above three times that of the conventional alternative current TIG welding. All the weld shape, weld microstructure and weld mechanical properties are fine. Except for argon shielding gas flowrate, other welding parameters, including welding current, welding speed, central coat width, central coat content and solvent, have great effect on the weld penetration of alternative current FZ-TIG welding for aluminium alloys.     

活性剂对6013铝合金薄板CO_2激光焊接工艺的影响(英文)

为了提高铝合金对激光的吸收率,改善焊缝表面成形,对1.8mm厚的6013铝合金板进行活性剂CO2激光焊接。活性剂主要采用的是对激光具有较高吸收率的氧化物和氟化物,将其焊前预涂覆于铝合金板上,然后施焊。结果表明:活性剂在提高CO2激光吸收率,增加母材金属熔化量方面具有明显的效果;氧化物活性剂对促进激光能量吸收的效果要强于氟化物,但氧化物形成熔渣的脱渣性较氟化物熔渣的差;在氧化物活性焊接过程中,气孔敏感性比较大,而氟化物活性剂在焊接过程中很少出现气孔。     

低碳钢熔化极等离子弧焊接工艺

对Q235低碳钢进行熔化极等离子弧焊接工艺试验,并研究其工艺参数对焊缝成形和熔滴过渡的影响.结果表明,与常规的熔化极惰性气体保护焊相比熔化极等离子弧焊接在提高焊接效率、减少飞溅和气孔等方面具有优越性.当其它条件不变时,焊缝熔宽随等离子电流增大而变宽,而对熔深和熔滴过渡类型影响不大;熔化极等离子弧焊接电流增大时,U - I相图的线簇随着电流增大而集中,熔滴过渡依次为短路过渡、大滴过渡和射流过渡.     

Control of nitrogen content and porosity in gas tungsten arc welding of high nitrogen steel

Abstract

In welding of high nitrogen steel (HNS), it is essential to control the nitrogen content and porosity in the weld metal. In this paper, the influence of shielding gas composition and heat input on the nitrogen content and porosity in the weld metal of HNS was investigated by gas tungsten arc welding. The experimental results indicate that the weld nitrogen content increases as N₂ in the shielding gas is increased in the same heat input of welding. The weld nitrogen content decreases with increasing the heat input for pure argon used as a shielding gas, whereas it increases with increasing the heat input for the shielding gas including some nitrogen. The nitrogen pore can be avoided when the nitrogen content in the shielding gas is <4% in the heat input range of 528–2340 J mm^–1.     

激光-MIG复合焊接参数的优化与选择

在激光-电弧复合焊接中,两种热源的集成导致工艺参数的调节更为复杂,如何根据实际需求来选择工艺参数一直是困扰该工艺的主要问题。对此,采用4mm厚Q235钢板进行了CO2激光-MIG(metalinertgas)复合焊接研究,探讨了激光功率、电弧电流对最大焊接速度的影响及其和接头间隙对焊缝成形的影响规律。结果表明:激光功率的增加更有利于最大焊接速度的提高,只有合理的工艺参数组合才能取得良好的焊缝成形。由此提出了CO2激光-MIG复合焊工艺参数的优化与选择方案。     

Welding of magnesium alloys with activating flux

Abstract

The effects of an activating flux on AZ31B alloy welding were investigated. Alternating current tungsten inert gas (ACTIG) welding was used to weld 5·0 mm thick AZ31B alloy plates with CdCl₂, AlF₃ and TiO₂ activating flux. Applying the activating flux on the AZ31B alloy surface led to an increase in weld penetration depth. Various welding conditions, such as welding current, welding arc length, welding shielding gas flowrate, welding speed and flux thickness, influenced to different extents the ability of the activating flux to increase weld penetration. Furthermore, a high speed camera was used to monitor the arc images during welding. It was found that the brightest region of the arc was broader when CdCl₂ and AlF₃ were used, while the stability of the arc was increased when TiO₂ was used, especially in the positive electrode period. In summary, it is important that a uniform flux layer is present at the alloy plate surface and suitable welding parameters are selected.     

Welding of titanium alloys with activating flux

Abstract

In the present paper, the effects of an activating flux on Ti–6Al–4V alloy welding were investigated. Tungsten inert gas welding was used to weld 8.0 mm thickness Ti–6Al–4V alloy plates. Results show that applying the activating flux on the Ti–6Al–4V alloy surface leads to an increase in weld penetration depth, whereas the corresponding weld bead width is reduced. It was also found that various welding conditions, particularly flux thickness, influence the effectiveness of the activating flux. Furthermore, a data acquisition system was used to monitor the current and voltage signals during welding. Results from monitoring of the welding current and voltage signals reveal that there is a clear correlation between the signals and the weld penetration when the welding arc is steady. Analysis of the acquired signals can be used to identify inconsistencies in weld penetration. In summary, to take advantage of the use of activating flux in Ti alloy welding, it is important that a uniform flux layer is present at the alloy plate surface and suitable welding parameters are selected.     

电流换向速率对2219铝合金VPTIG焊缝的影响

研究开发了一种适用于铝合金材料的新型超快速变换变极性方波电弧焊接技术,以2219-T87高强铝合金为试验对象,分别采用常规变极性和超快变换变极性TIG电弧焊接工艺,研究了变极性电流的换向速率对焊缝气孔敏感性和接头力学性能的影响.结果表明,提高变极性电流上升沿和下降沿的变化速率,减少电流过零时间,可显著降低2219-T87高强铝合金焊接接头的气孔敏感性,焊缝中气孔数量明显减少甚至消除;由于焊缝熔合区的软化问题,焊接接头抗拉强度和断后伸长率的增加幅度不大,分别提高了8.97%和12.6%.     

Laser welding of AZ61 magnesium-based alloys

Laser welding of AZ61 magnesium alloys was carried out using a CO2 laser welding experimental system. The welding properties of AZ61 sheets with different thickness were investigated. The effect of processing parameters including laser power, welding speed and protection gas flow was researched. The results show that laser power and welding speed have large effect on the weld width and joint dimensions. Protection gas flow has relatively slight effect on the weld width. The property test of three typical joints indicates that microhardness and tensile strength in weld zone are higher than that of AZ61 base metal, Joints with good appearance and excellent mechanical properties can be produced using CO2 laser welding method. The microstructure with small grains in weld zone is believed to be respoasible for the excellent mechanical properties of AZ61 joints.     

高强铝合金PVPPAW焊接参数优化与性能分析

对10 mm厚7075铝合金板材进行脉冲变极性等离子弧焊，研究了焊接电流和离子气流量的变化对焊缝成形系数的影响规律，确定了较优的焊接参数并获得了成形良好的焊缝，对该焊接接头力学性能进行分析. 结果表明，焊缝成形系数随着焊接电流的增大先减小后增大，随着离子气流量增大逐渐减小，较佳的焊缝成形系数区间为1.1 ~ 1.3，焊接电流比离子气流量对焊缝成形的影响更大. 当脉冲焊接电流为250 A/290 A，离子气流量为2.0 L/min时焊缝形貌较佳，接头焊缝区为树枝状晶，焊缝处的抗拉强度为397.9 MPa，约为母材的67.5%，焊缝的性能较好.