引弧棉在埋弧自动焊中的应用

窄间隙埋弧焊作为一种高效的焊接方法 ,被广泛用于中厚钢板及其他钢结构的焊接中。但是由于焊接参数大的限制 ,在起弧装置上难以实现高频附加引弧等先进方式 ,仍然延续使用短路回抽的方式 ,起弧效率不高 ,特别是国内存量很大的交流焊机起弧困难更为明显 ,给现场施工带来成本和工期的浪费。咸阳五星科技研制开发的“钢絮”牌引弧棉 (专利号 :ＺＬ0 0 2 2 0 0 6 8.6 ) ,是一种获国家专利的新型焊接辅助材料。采用优质钢材拉制成极细金属纤维细丝 ,形同棉絮一般 ,纤维直径小于 0 .0 0 3ｍｍ ,在很小的电流和很小的电压即可“引燃”电弧 ,焊接过…     

埋弧自动焊紧贴接边双面焊操作技术

主要阐述了埋弧自动焊紧贴接边双面焊操作技术,通过采用恰当的焊接工艺,并严格控制焊接规范,可使焊接质量合格率达到９９％以上,收到满意的效果,而且此方法简单,容易掌握,具有培训教学和实用推广的价值。     

埋弧焊车结构探讨及新型自动埋弧焊车的研制

埋弧焊车在自动焊焊接中是关键设备，是提高工程效率、焊接质量和自动化水平的重要保证。为了满足重型机械制造、造船、桥梁、交通运输、构件等行业飞速发展的要求，迫切需要研制能够受用户欢迎的、具有先进性能、高稳定性和可靠性、使用方便等优点的新型自动焊车。为此，我们对多种国产和进口焊车的性能、结构、生产加工工艺等各项经济技术指标进行了全面的分析，对市场调研及用户使用中反馈的建议进行了研究总结并做了大量的工艺实验，制定了相应的对策。１　对旧型焊车的研究和分析从设计结构、焊车性能、加工工艺、质量检测等方面进行分…     

埋弧自动全位置焊的构想

本文主要叙述了对埋弧自动全位置焊的构想，结合长距离输送管道建设焊接工程的实际需要，将引进的只适用于水平位置和横焊位置的埋弧自动焊设备改装，使其能够进行全位置焊，并分别从焊接机械手的设计，环形导轨的设计，小行行车机构的设计，焊剂的堆敷及防脱落装置的设计，焊剂的输送和回收率系统的设计等方面加以论述，为长输管道实现全自动机械化焊接提供了新的思路，这种高效的焊接方法，将具有广阔的应用前景。     

碎焊丝在埋弧自动焊中的应用

对填加碎焊丝的埋弧自动焊进行了焊接工艺试验,通过相关标准检验结果表明,其接头性能达到了使用要求,在埋弧焊中填加碎焊丝对提高我国焊接自动化水平有一定的重要意义。     

大型自动埋弧焊成套设备的研究

本文介绍了一种结构新颖的埋弧焊成套设备,并就埋弧焊成套设备中的一些主要部件作了分析说明。该设备采用的平移式横梁结构、三点式九滚轮导轨装置以及焊缝自动跟踪装置,对满足同平面内多道长焊缝的焊接有独到之处。     

大型储罐的埋弧自动横焊

埋弧自动焊是焊接中厚板常用的焊接方法，但常规用在平、角焊位置的焊接。并介绍在横位置的横焊技术。     

ST65厚壁管的自动埋弧焊

0 前言液压启闭机油缸缸体的焊接,采用自动埋弧焊工艺。缸体材质为ST65(德国产),规格为φ635mm×86mm,结构见图1。技术要求为:①焊缝质量应符合JB1152—87超声波探伤Ⅱ级标准,②焊缝力学性能σ_s≥305MPa,δ_5≥17％、A_k≥31J;③焊缝试验压力32MPa;④焊后缸体不直度≤3.5mm。ST65钢的碳当量C_(e q)=0.66％,焊缝冷裂倾向较大,焊接性差。通过焊接工艺评定,选择了合理的焊接材料及焊接工艺参数,成功地焊接了     

埋弧自动焊设备的使用和维修

埋弧自动焊设备的使用和维修ＡｐｐｌｉｃａｔｉｏｎａｎｄＭａｉｎｔｅｎａｎｃｅｏｆＳｕｂｍｅｒｇｅｄＡｒｃＷｅｌｄｉｎｇＥｑｕｉｐｍｅｎｔｓＸｉ′ａｎＣａｒｒｉｅｒｗｏｒｋｓｏｆＭｉｎｉｓｔｒｙｏｆＲａｌｌｗａｙＧａｏＺｏｎｇｒａｎｇｅｔａｌ铁道部西安...     

一种新型埋弧焊控制电路的分析

介绍了一种新型的埋弧焊控制电路。为满足维修的需要，自行设计了脉宽控制电路。     

振动埋弧焊工艺

振动埋弧焊工艺是一种在焊接过程中通过给焊件施加振动来改善焊接性能的新工艺.介绍了在西气东输阀门焊接中运用振动埋弧焊进行厚板焊接的试验,就残余应力、焊接变形、金相三个方面对常规埋弧焊和振动埋弧焊工艺进行比较,对振动埋弧焊工艺进行初步探讨.试验结果表明,振动埋弧焊工艺能有效地降低焊接残余应力和变形,并细化晶粒.     

新一代的埋弧焊

林肯公司推出了更先进的具有可变极性输出的埋弧焊电源。对于交流波形,在不改变焊接电流和电压的前提下,无论是单弧应用或多达5弧的应用,均可通过改变正负半波的平衡来控制焊接的熔深和熔敷率。     

摆动电弧埋弧焊的数学建模与仿真

针对变速送丝调节系统埋弧焊的特点,利用MATLAB软件建立了V型坡口扫描单元的仿真模型、焊接电源单元的仿真模型、焊接电弧单元的仿真模型,并在此基础上形成了系统的整体仿真模型,全面研究了坡口形状、焊接电源和熔滴过渡形式对输出焊接电流的影响机理;分析了电弧传感器的主要参数对焊缝偏差信息、焊接工艺参数的影响规律;探讨了常见干扰因素的影响,为建立摆动电弧埋弧焊焊缝自动跟踪系统提供理论依据.     

埋弧焊焊接及校正过程数值模拟

针对金属结构在焊后易产生残余应力和焊接变形的问题,以一种对焊钢制梁为例,采用有限单元法模拟埋弧焊焊后的残余应力和变形.结果表明,钢制梁焊后存在较大的残余应力,且纵向残余应力大于横向残余应力.以焊接结果为初始条件,分析是否考虑残余应力对校正后钢制梁应力分布的影响,结果显示校正后焊缝处仍存在较大的应力,因此焊接残余应力不能...     

单电源双丝埋弧自动焊研究

单电源双丝埋弧自动焊是一种高熔敷速率、高焊接速度、低热输入的埋孤焊方法.通过改变焊丝排列方式和丝间距,其焊缝成形、熔深/熔宽、稀释率可得到更充分的调节.既可适用于稀释率要求较低的耐磨或耐腐蚀表面的埋弧堆焊,亦可适用于各种对接、角接焊缝的单道或多道高速埋孤焊.简述了这种焊机的结构要点,指出了电源及送丝系统的合理配置要求.     

Computer-aided experiment on arc welding

Fatigue properties of cast aluminium welded joints by friction stir welding (FSW) and MIG welding were investigated, comparing with that of the base plate. Fatigue crack propagation tests for the da/dN ? ΔK relation and bending fatigue tests for the S–N relation were carried out. Fatigue cracks in both FSW and MIG specimens were accelerated, when the fatigue crack tip reached the stir zone or the weld metal. This behaviour was discussed based on the crack closure induced by the crack surface roughness and the residual stress. In the S–N properties, the influence of specimen surface finishing on fatigue life was also examined. Fatigue lives of the FSW and MIG specimens in the ‘as weld’ condition were in the range of the largely scattered base plate fatigue lives, in spite of the different fatigue crack initiation sites in each specimen such as the porosity in the base plate, the tool mark bottom in the FSW and the weld toe in the MIG. The FSW specimens with the polished surface showed the particular improvement in fatigue strength for finite fatigue life.     

Optimization of submerged arc welding process parameters for overlay welding

In this work, we evaluated the influence of welding variables on weld beads applied by the submerged arc process (SAW) with conventional current, aiming future application in overlays against corrosion. Segments of steel API 5L Gr B pipe as substrate, a 1.13 mm-diameter electrode wire of nickel alloy, classification AWS ERNiCrMo-4 (Hastelloy C-276) as filler metal, and a flux neutral, basic and crowded were used. The variables voltage, wire feed speed and contact tip to work distance (CTWD) were analysed, with the remaining parameters constant by an experimental design with full factorial design in two-level and central points. Statistically significant and predictor mathematical models for response dilution and average current were obtained. However, for the response reinforcement/width, the model was characterized as statistically significant, but not predictive, and containing a lack of fit. The CTWD was the most significant variable reducing the dilution.     

Thermal conduction theoretical analysis of temperature distribution during multiple-electrode submerged arc welding

In recent years, in order to reduce the costs of transportation and construction of pipelines, which are often constructed using multiple-electrode submerged arc welding (SAW), higher joint performance is required. Therefore, there has arisen the need to understand theoretically and control appropriately metallurgical and mechanical characteristics in heat-affected zone (HAZ), which has a significant influence on the strength and toughness of welded joints. Commonly, metallurgical phenomena in HAZ are evaluated based on the highest temperature and the cooling rate. Therefore, in order to control metallurgical and mechanical characteristics in HAZ by means of the welding conditions, evaluating the temperature distribution and the temperature history near the melted zone is essential. However, a detailed investigation of the temperature distribution for multiple-electrode SAW has not yet been carried out enough. In this study, in order to investigate the temperature distribution and histories during multiple-electrode SAW, the experimental results are compared with the theoretical results. In the theoretical analysis, the temperature rise equation in multiple heat sources welding is developed using the method of summation. Furthermore, on temperature distribution during welding, the effects of multiple heat sources, such as the number of heat sources and the distance between each electrodes, are considered quantitatively through the thermal conduction theoretical analysis. As the result, the distance between lead heat source and final heat source primally influences the area with the difference between a single heat source welding and multiple heat sources welding. Based on the results, it is expected to control temperature distribution near melted zone by more appropriate heat input characteristics, which is depended on heat source arrangement.