09MnNiDR钢焊接试验研究

采用经验公式分析了09MnNiDR钢的焊接接头裂纹敏感性,研究了焊接工艺对焊接接头性能的影响。通过分析和斜Y型坡口焊接裂纹试验表明09MnNiDR具有良好的焊接性能,在室温条件焊接不会产生焊接冷裂纹。通过采用合理的焊接工艺,分别采用钨极氩弧焊、焊条电弧焊和埋弧焊焊接09MnNiDR钢,得到综合性能良好的焊接接头,能够满足工程需要。     

紫铜与低合金钢异种金属MIG焊探究

通过紫铜与低合金钢的熔化极氩弧焊的焊接实践,对铜钢焊接易产生裂纹,未熔合和气孔等缺陷进行了试验分析,并采用了合理的焊接工艺,提高了焊接接头的力学性能,保证了工件质量。     

1Cr13不锈钢电磁组件焊接裂纹分析及工艺措施

1Cr13马氏体不锈钢焊接性能差,极易产生冷裂纹缺陷。某航空产品零件的材料为1Cr13,在激光焊后焊缝产生延迟裂纹。现针对工件无法焊前预热及其结构特点,用氩弧焊代替激光焊,通过焊接工艺控制解决该产品焊接裂纹问题,避免产生焊缝冷裂纹。     

用钨极氩弧焊修复液力变矩器

液力变矩器的工作叶轮,由铝合金铸造而成.因铝合金铸造时有较大的结晶温度区,线膨胀系数大,凝固时产生的体积收缩率大,因此内应力较大,易产生晶间裂纹.工作时因其内部油压波动和油中杂质侵蚀的作用,均会造成变矩器不同程度的损坏(如:罩轮或工作轮产生裂纹).变矩器在出厂时都经过严格动平衡检验,在不增加重量、不影响动平衡的情况下,我们采用钨极氩弧焊(TIG)修复裂纹,取得了满意的效果.方法如下:     

钽—12钨焊接工艺试验研究

Ta— 12W属难熔金属合金 ,易氧化 ,焊接时出现冷、热裂纹的倾向大 ,严格的气体保护或在真空状态下焊接是获得优良焊接接头的关键 ,介绍Ta— 12W的氩弧焊及电子束焊接工艺性试验、缺陷的产生和防止、焊接性能等。     

基于焊接缺陷的厚板零件焊接工艺优化

针对T型厚板零件焊接过程中易产生未熔合、未焊透、裂纹等问题,本文在其焊接工艺性分析的基础上,提出了焊前预热、焊接过程中保温、采用手工钨极氩弧焊打底及手工电弧焊堆焊等优化措施,并提出要对焊接完成的零件及时去应力退火等技术要求。经X光检测结果表明,优化后的焊缝焊接质量良好,未发现焊接缺陷,满足设计要求。     

TA15钛合金钨极氩弧焊焊接接头力学性能研究

TA15钛合金钨极氩弧焊焊缝、热影响区、母材的微观组织差别明显,晶粒尺寸依次减小.焊接件的疲劳试验结果分析表明,热影响区是焊接接头的薄弱部位,疲劳裂纹大多萌生于焊接热影响区区域.疲劳破坏试样断口的SEM(scanning electron microscope)分析表明疲劳裂纹大多起源于焊接热影响区的气孔处.     

用钨极氩弧焊修复液力变矩器

液力变矩器的工作叶轮,由铝合金铸造而成。因铝合金铸造时有较大的结晶温度区,线膨胀系数大,凝固时产生的体积收缩率大,因此内应力较大,易产生晶间裂纹。工作时因其内部油压波动和油中杂质侵蚀的作用,均会造成变矩器不同程度的损坏(如:罩轮或工作轮产生裂纹)。变矩器在出厂时都经过严格动平衡检验,在不增加重量、不影响动平衡的情况下,我们采用钨极氩弧焊(TIG)修复裂纹,取得了满意的效果。方法如下:     

压力容器焊接结晶裂纹与防止措施

介绍了压力容器焊接过程中结晶裂纹产生的机理、影响因素及防止措施。     

镍基耐蚀材料结晶裂纹的研究综述

总结了解研究焊接结晶裂纹的几种主要试验方法，并简述了影响其焊接结晶裂纹的主要元素。     

灰铸铁缸体电弧冷焊修复工艺研究

缸体是汽车铸件中质量最大的一个铸件,缸体制造和使用过程中出现裂纹、磨损、渗漏等缺陷,采用电弧冷焊工艺进行修复,分析了缸体铸件的焊接性,焊接时可能出现白口组织和裂纹,采用同质焊缝和异质焊缝的两种电弧补焊工艺、同时结合相应的工艺措施可获得理想的修复效果。     

离心压缩机叶轮补焊工艺研究及应用

针对压缩机叶轮在热处理后出现的裂纹缺陷,采用手工氩弧焊工艺进行补焊。通过与手工电弧焊补焊工艺的力学性能和显微组织进行对比分析,发现焊接接头具有良好的力学性能,接头强度满足设计要求,并且避免了传统手工电弧焊工艺补焊造成的飞溅、弧坑裂纹、气孔等缺陷,提高了产品一次性补焊合格率,完善了低合金高强钢焊接叶轮制造工艺规范。对某大型压缩机叶轮进行实际补焊应用,叶轮经过超转试验后,表面检测合格,完善了低合金高强钢焊接压缩机叶轮的制造技术。     

变极性等离子弧焊接熔透信息的检测与分析

通过对铝合金3003变极性等离子弧穿孔立焊熔池振荡行为的研究,发现熔池振荡频率与焊接熔透之间的内在规律。在变极性电流的作用下,焊接熔池产生振荡,可以通过对电弧电压频谱分析获得熔池固有振荡频率。分别建立变极性等离子弧穿孔立焊未熔透及完全熔透熔池模型,并分析焊接电流的变化对熔池固有振荡频率的影响,发现焊接电流大小对其影响很小,可以忽略。为了验证该模型的准确性,进行理论与实测分析,结果表明,理论值与实测值相吻合。熔池固有振荡频率主要取决于熔池宽度、深度及材料密度等参数,而其他焊接参数对其没有直接影响。因此,熔池振荡频率可间接反映焊接熔透信息,为焊接质量自动控制提供了理论支持。     

Multisensor-based monitoring of weld deposition and plate distortion for various torch angles in pulsed MIG welding

Manufacturing companies often fail to maintain good weld quality due to poor arc stability and distortion after welding. Weld quality can be improved by reducing the transverse shrinkage and the angular distortion in butt welding. The welding deposition efficiency is also an important economic factor. In this work, various pulse voltage parameters have been varied along with welding torch angle in pulsed metal inert gas (P-MIG) welding. The experimental results revealed that the peak voltage is the dominant pulse voltage parameter. Various sensors were also used to monitor arc current, arc voltage, arc sound, and also weld temperature. A strong relationship between arc sound (as well as arc power) and transverse distortion (as well as metal deposition) was found to exist in P-MIG welding. The frequency domain features of welding arc sound were also extracted and correlated to the process characteristics.     

高压锅筒集中下降管的焊接

分析了生产高压锅筒中集中下降管焊接易出现的问题,提出了集中下降管埋弧自动焊焊接工艺,减少集中下降管角焊缝焊接缺陷,提高了生产效率。     

基于电弧传感器的焊缝自动跟踪系统的研究

研制电弧传感器的焊缝自动跟踪系统 ,采用具有先进性能的开关型MIG MAG脉冲焊接电源 ,将电流和电压信号同时用作传感信号 ,通过电弧的扫描 ,既实现了焊接过程的自动跟踪 ,又解决了打底焊道的熔透问题 ,大大提高了产品焊接质量。     

外加磁场对高速GMAW电弧和熔池行为的主动调控效应

在熔化极气体保护焊(Gas metal arc welding,GMAW)过程中,当焊接速度超过临界值后,焊缝成形变差,出现咬边和驼峰焊道,无法满足生产要求。研究证明,熔池中动量很大的后向液体流是产生驼峰焊道的主要原因。自主研发外加磁场发生装置,向熔池施加横向电磁力,对后向液体流进行主动干预,并调控熔池流态,从而抑制驼峰焊道的形成。在Q235低碳钢板上开展焊接工艺试验,获得了不同磁感应强度下的焊缝表面成形;采用高速摄像技术,拍摄焊接过程中的电弧和熔池图像,分析外加磁场对电弧形态、熔池流场和焊缝成形的影响规律,初步揭示外加磁场抑制驼峰焊道的机理。试验结果表明,外加横向磁场能明显调控熔池流态,减小后向液体流的动量,并能有效抑制驼峰焊道和咬边等缺陷,显著改善焊缝成形,提高临界焊接速度。     

活性激光电弧复合焊接法研究

为了进一步提高激光电弧复合焊接的熔深,提出活性激光电弧复合焊接法。在氧气的保护下,用小功率光纤激光在待焊焊件表面进行预熔处理,使表面熔化生成一层氧化层,然后用激光电弧复合焊接覆盖氧化层,达到增加熔深的目的。结果表明,激光预熔后进行激光电弧复合焊接,电弧明显收缩,熔深增加1.5倍左右,表面成形良好。激光预熔后,焊缝含氧量增加,熔池表面张力温度系数由负变正,使得复合焊接熔深增加。研究工艺参数对焊缝熔深和熔宽的影响,随着激光预熔功率的增加,熔深增加熔宽减小;随着电流的增加,熔深熔宽都增加,但激光预熔后的焊道增加更快。随着复合焊接速度的增加,熔深和熔宽都减小。随着复合焊接中激光功率的增加,熔深增加,对熔宽的影响较小。利用活性激光电弧复合焊接法,可以得到较为细小的焊缝组织,提高焊接接头的抗拉强度,能达到母材抗拉强度的95%,且面弯和背弯180°后未出现裂纹,表明接头具有良好的韧性。     

Evaluation on microstructure and mechanical properties of high-strength low-alloy steel joints with oscillating arc narrow gap GMA welding

Abstract with the purpose of improving weld joint quality and productivity, the oscillating arc narrow gap gas metal arc (GMA) welding was employed in welding quenched and tempered high-strength low-alloy thick steel. The microstructure and mechanical properties of weld joints were evaluated, namely micro-hardness, tensile strength, and low-temperature impact toughness. The test results indicated that mechanical properties of weld joints with oscillating arc narrow gap GMA welding were excellent and found to meet stipulated requirements. Oscillating arc narrow gap GMA welding is a promising process for welding quenched and tempered HSLA thick steels due to the low energy input and narrow square-butt groove.     

Prevention of humping bead associated with high welding speed by double-electrode gas metal arc welding

Manufacturing productivity can be improved by increasing the welding speed. However, humping bead will occur when welding speed is beyond a certain value. An experimental system of double-electrode gas metal arc welding (DE-GMAW) was developed to implement high speed welding and prevent from humping bead formation. The DE-GMAW appropriately partition the heat energy between the wire and the base metal so that higher deposition rate of filler wire and suitable shape and size of weld pool are ensured. The arc images captured during DE-GMAW process were used to optimize the geometric parameters between the gas tungsten arc welding and the gas metal arc welding (GMAW) torches. The main arc and bypass arc integrated well and satisfactory weld bead formation was obtained. Through observing the weld pool behaviors from side view during DE-GMAW process, it was found that the height of both solidified and molten region at the pool tail is almost flat so that no humping bead was formed during DE-GMAW with the welding speed up to 1.7?m/min. The side view images of weld pool in DE-GMAW were compared with those in conventional GMAW, and the reason why DE-GMAW can suppress humping bead is shortly discussed.