高压钨极氩弧自动焊接

研究了以0．1-0．7MPa压缩空气为舱内加压气体的钨极氩弧自动焊接。在提高高压焊接试验舱舱内设备抗燃性能的同时,供应足够的保护气体,焊接过程稳定。设计了钨极氩弧自动焊接试验样机。采用接触引弧,以高压密封圆形连接器实现了舱内焊接机头线缆的统一穿舱,特别是以弧长代替电压作为控制变量消除了焊接电缆的影响。16Mn平板焊接实验证明,虽然不同空气压力、不同位置实现单面焊自由双面成形的工艺参数明显不同,但是采用脉冲焊接均可以获得性能优良的焊接接头。     

小型钨极直流氩弧焊机的设计

介绍了一种主要用于建筑及装饰装修行业小型钨极直流氩弧焊机的设计。这种机型的特点是性能好,可靠性高,操作,维修简单,成本低廉,易于制造。     

日本晶闸管式钨极氩弧焊机的使用与维修

介绍了日本晶闸管式钨极氩弧焊机的操作原理,使用和维修技术。     

NSA—500—1型钨极氩弧焊机故障修复四例

ＮＳＡ－５００－１型钨极氩弧焊机系引进国外技术进行改制的焊机,该型号焊机广泛应用于铝及铝合金容器、汽车铝合金零部件、飞机及火箭铝合金部件及附件的制造、维修中的焊接。其电路原理如图１所示。图１ＮＳＡ－５００－１型钨极氩弧焊机原理电路图现将我部在使用中出...     

钨极氩弧焊机的故障及排除方法

1.电源开关接通,指标灯不亮 (1)原因: ①电源开关损坏; ②熔断器烧断; ③控制变压器损坏; ④指标灯损坏。 (2)处理方法: ①更换开关; ②更换同规格熔断器; ③用万能表和低压摇表检查变压器损坏部位,轻者采用绝缘处理,严重者采取重绕线圈或     

WSE—500多功能脉冲钨极氩弧焊机故障修复几例

WSK-500多功能脉冲钨极氟弧焊机,系牡丹江兴达电子焊接总公司引进日本大项变压器公司制造技术生产。该焊机可进行交直流nG焊、脉冲＊G焊、刀G点焊,交直流手工电弧焊及切割等,在航空航天、汽车等领域内应用较多。由于焊机没有原理图,给维修带来一定困难。现将使用交流ACThG焊,焊接铝合金中出现的一些常见故障修复方法介绍如下,供电焊机修理的同行们参考。例1按焊枪按钮开关,有引弧脉冲产生、红色基值电流指示灯发光,不起弧、无焊接电流输出,调节面板上的起始电流旋钮以增大起始电流,仍然不起弧。处理方法：打开焊机检查焊接主…     

WS—100直流钨极氩弧焊机的研制

介绍了所研制的用于焊接薄板的直流钨极氩弧焊机的电路及其工作原理，外特性的形成、电流的调节、引弧及调试中的几点体会。     

铸铁表面钨极氩弧重熔强化的研究

为了提高铸铁表面的耐磨性,以ＨＴ２００为试验材料,用钨极氩弧对其进行了局部重熔强化的系统研究,提出了相关工艺参数对重熔处理后表层组织和影响规律。同时与镍基自熔合金喷焊及铸铁激冷处理表面强化法做了对比试验,结果表明,铸铁钨极氩弧重熔后激冷后是有效提高其耐磨性,发挥自身潜力,降低成本的一项新工艺。     

方波交流脉冲钨极氩弧焊机的研制

阐述了方波交流脉冲钨极氩弧焊机主与控制系统工作原理及其设计方法。控制系统全部采用电子线路。利用脉冲调制技术。以晶闸管为功率调节元件，使同具有冲输出功能。该焊机还用于直流钨极氩弧焊。     

Double-sided gas tungsten arc welding process on TC4 titanium alloy

TC4 titanium alloy was welded by double-sided gas tungsten arc welding（GTAW） process in comparison with conventional GTAW process, the microstructure and mechanical performance of weld were also studied. The results indicate that double-sided GTAW is superior over regular single-sided GTAW on the aspects of increasing penetration, reducing welding deformation and improving welding efficiency. Good weld joint was obtained, which can reach 96.14% tensile strength and 70.85% elongation percentage of the base metal. The grains in heat-affected zone（HAZ） are thin and equiaxed and the degree of grain coarsening increases as one moves to the weld center line, and the interior of grains are α and α′ structures. The coarse columned and equiaxed grains, which interlace martensitic structures α′ and acicular α structures, are observed in weld zone. The fracture mode is ductile fracture.     

Gas tungsten arc welding of network structured titanium matrix composite

The microstructure and property evolution of TiBw/Ti6Al4V composite was investigated after gas tungsten arc welding process. The results showed that the heat affected zone (HAZ) exhibited unchanged reinforcements, while the fusion zone (FZ) exhibited refined TiBw with refined network scale. Meanwhile, the matrix in HAZ presented the transformed β microstructure, while the refined columnar grains existed in FZ. Moreover, increasing heat input can further decrease the refined network size. Consequently, the ultimate tensile strength of the welded composite reaches 98% that of the parent composite (PC); while the yield and tensile strength at 500°C are even higher than those of the PC. The refined microstructure and the transformed β phase also lead to noticeable enhancement of the microhardness.     

A dynamic welding heat source model in pulsed current gas tungsten arc welding

A time-dependent welding heat source model, which is defined as the dynamic model, was established according to the characteristic of PCGTAW. The parabolic model was proposed to describe the heat flux distribution at the background times. The recommended Gaussian model was used at the peak times due to the bell-shaped temperature contour. The dynamic welding heat source was composed of these two models with a function of time.     

水下焊接高压空气环境下GTAW电弧特性

利用自制的高压干法水下焊接模拟试验平台,首次系统研究了高压空气环境下GTAW电弧特性.结果表明,空气环境下GTAW电弧的安全压力范围可高达0.7 MPa;高压空气环境下的GTAW电弧电压值为12～19 V,略高于同样压力的氩气环境下氩弧值,其电弧静特性在电流大于50 A时呈上升特性;随着空气环境压力升高,GTAW电弧的弧柱电场强度与阴阳极压降增加,导致电弧静特性曲线上移,其上升率约为5～10 V/MPa.在试验数据的基础上,建立了高压空气环境下的GTAW电弧电压数学模型,该数学模型可用于综合分析计算电弧长度、环境压力和焊接电流对GTAW电弧电压的影响.     

焊丝对工业纯铜和304不锈钢钨极氩弧焊接的影响(英文)

采用不同焊丝对工业纯铜和304不锈钢进行钨极氩弧焊接。结果表明,采用铜做焊丝时,焊缝无任何缺陷生成,而采用304不锈钢和Ni-Cu-Fe合金为焊丝材料时,焊缝中有凝固裂纹和未熔化区存在。在最优条件下,焊缝的抗拉强度能达到铜材的96%。焊缝在弯曲到180°下也没有分离、撕裂和断裂等现象发生。这表明铜是一种较好的工业纯铜与304不锈钢GTA焊的焊丝材料。     

紫铜厚大结构件钨极氩弧焊热裂纹形成机理

对紫铜厚大结构件钨极氩弧焊(GTAW)热裂纹形成机理进行了研究.对热裂纹的动态形成过程进行观察和分析,在普罗霍罗夫理论基础上优化了热裂纹形成判据,并建立了基于刚性拘束热裂纹试验的紫铜厚板GTAW有限元模型.结果表明,内部变形率Δε是促使开裂的内因,得到HS201焊缝金属在脆性温度区间内(BTR)的横向拉伸应力及Δε的变化规律,并与其高温延性进行对比,得到不预热工艺下热裂纹产生的原因.为了防止热裂纹的出现,模拟并分析了不同预热温度下HS201焊缝金属的Δε的变化规律,预热温度由500℃降为420℃即可避免热裂纹出现.     

A novel molten wire tungsten inert gas welding process

ABSTRACT

A novel molten wire tungsten inert gas welding process was presented. In this process, a welding arc is used to melt the workpiece, and a melting arc is used to melt the feeding wire. Metal transfer is separated from the melting of the wire and the workpiece, and the arcs are stable no matter the droplet transfer mode is spraying or globular. The spatter rate in the process is close to zero. Mechanical properties of low carbon steel joint bonded with this process are superior to those bonded with the metal inert gas welding process.     

Modeling corrosion behavior of gas tungsten arc welded titanium alloy

The pitting corrosion characteristics of pulse TIG welded Ti-6Al-4V titanium alloy in marine environment were explained. Besides the rapid advance of titanium metallurgy, this is also due to the successful solution of problems associated with the development of titanium alloy welding. The preferred welding process of titanium alloy is frequently gas tungsten arc（GTA） welding due to its comparatively easier applicability and better economy. In the case of single pass GTA welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. The benefit of the process is utilized to obtain better quality titanium weldments. Four factors, five levels, central composite, rotatable design matrix are used to optimize the required number of experiments. The mathematical models have been developed by response surface method（RSM）. The results reveal that the titanium alloy can form a protective scale in marine environment and is resistant to pitting corrosion. Experimental results are provided to illustrate the proposed approach.     

片状偏钨极电弧特性的数值模拟

基于流体力学和麦克斯韦方程组,建立片状偏钨极电弧三维数学模型,计算得到电弧温度场、流场、电场及电流密度分布.结果表明,片状偏钨极厚度方向电弧温度场、流场、电场及电流密度呈对称分布;相同焊接工艺参数下,片状偏钨极电弧最高温度、最大流速及电流密度小于圆柱钨极电弧;电流密度受片状偏钨极前端斜边引导作用和电弧惯性后拖效应的共同影响,其分布范围沿钨极宽度方向扩展,且电弧等温线在该方向上扩张;片状偏钨极前端斜边倾角的改变,会引起电流密度在钨极前端局部集中,并导致阴极下方高温区和阴极射流沿斜边偏移.