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等离子弧焊接在中厚板焊接领域具有重要的应用前景.自主设计搭建了气流再压缩等离子弧焊接系统,开展了气流再压缩等离子弧焊接新工艺试验研究.通过焊接过程监测系统分析焊缝成形,温感扫描图可以比较准确的反映实际焊缝成形.针对8 mm厚的304不锈钢,焊接电流为150 A时,常规等离子弧焊接熔深为6.53 mm;气流再压缩等离子弧焊接可以完全熔透工件,且正面焊缝和背面焊缝成形良好.结果表明,相同电流条件下,与常规等离子弧焊接相比,气流再压缩等离子弧焊接电弧电压升高;气流再压缩等离子弧焊接可以提高焊接熔透能力. 相似文献
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提高电弧穿透能力是等离子弧焊接领域的重要课题.自主设计并搭建了金属粉末再压缩等离子弧焊接新工艺试验平台,采集焊接过程电信号、视觉信号、弧光光谱信号等,并从焊缝成形、电弧电压、熔融金属过渡、弧光光谱等方面对金属粉末再压缩等离子弧焊接过程进行了初步的研究.在相同焊接电流195 A条件下,与常规等离子弧焊接工艺相比,金属粉末再压缩等离子弧焊接焊缝熔深增加1.29 mm、熔宽减少1.65 mm、电弧电压升高0.63 V.在波长为230 ~ 270 nm范围内,与常规等离子弧焊接相比,金属粉末再压缩等离子弧焊接中Fe和Cr元素的特征谱线明显增多. 结果表明,在相同电流条件下,与常规等离子弧焊接相比,金属粉末再压缩等离子弧焊接电弧穿透能力增强. 相似文献
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针对活性剂等离子弧焊焊接过程,对焊接电弧外形的变化,焊接电弧电压与活性剂之间的关系进行了研究,采用红外热像伪着色法测定了活性剂等离子弧焊焊接电弧温度场,并建立了活性剂等离子弧焊焊接电弧热流密度径向分布模型.研究结果表明,活性剂等离子弧焊焊接电弧收缩,弧尾翼消失,尾焰加大,电弧穿透力增强,电弧电压升高;活性剂等离子弧焊焊接电弧的温度分布比较紧凑,温度场外形窄,温度分布范围较集中,电弧径向温度梯度较大;电弧径向温度分布呈现正态Gauss分布模式;使用活性剂后的焊接接头性能与未使用活性剂焊接接头相当. 相似文献
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基于双区域近似电弧模型的理论,研究了工艺参数对喷嘴出口处转移型焊接等离子弧的影响,给出了喷嘴出口处等离子电弧的伏安特性曲线,以及在不同离子气流速和喷嘴直径的条件下,电弧的弧柱半径及压力随焊接电流变化的曲线,并与试验数据进行比较,比较结果表明,计算结果与试验测量值吻合良好。同时还分析了喷嘴直径、钨极内缩量以及离子气流速在相应的焊接电流下对等离子弧功率与电弧力的影响,并绘出曲线图。研究结果表明,对于中小电流规范下的转移型等离子弧焊接,采用双区域近似电弧模型来研究喷嘴出口处等离子弧的特性是可行的,该模型计算简便,可为得到高质量等离子弧焊接的设计及生产提供理论基础。 相似文献
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《机械制造文摘:焊接分册》2008,(4)
20084096等离子焊接电弧流场数值分析/王健…//焊接.-2008(2):27~31以直流正极性等离子焊接电弧为对象,依据磁流体动力学理论构建电弧的数学模型,运用有限元分析14软件ANSYS对二维稳态下轴对称等离子焊接电弧进行了数值分析,得到了焊接电弧的温度场、速度场的形态分布特征。从等离子弧电流密度及离子气流场角度揭示了等离子电弧高热特性的原因。分析了等离子电弧的电场特性、离子气和保护气的流场特性以及不同焊接电流、离子气流量对电弧特性的影响。分析结果表明,离子气流量与电弧力成线性关系,保护气流量的选择导致的涡流大小影响电弧稳定性。图9表1参620084097继电保护设备柜体的螺栓焊接/王青阳//电焊机.-2008,38(2):74~75现在柜体表面大多采用静电喷涂,板面对螺栓焊接质量要求很高。采用螺栓闪光电阻焊代替焊条电弧焊焊接螺栓,其可靠性高,焊后对板面无烧伤,且能够提高产品质量、降低成本、提高功效。经试验证实完全可以满足产品质量要求。图1表420084098基于LabVIEW脉冲焊接过程稳定性评估系统/王卫彬…//电焊机.-2008,38(1):20~22GMAW-P焊接过程的稳定性对焊接质量有重要... 相似文献
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《机械制造文摘》2008,(4)
20084096等离子焊接电弧流场数值分析/王健…//焊接.-2008(2):27~31以直流正极性等离子焊接电弧为对象,依据磁流体动力学理论构建电弧的数学模型,运用有限元分析14软件ANSYS对二维稳态下轴对称等离子焊接电弧进行了数值分析,得到了焊接电弧的温度场、速度场的形态分布特征。从等离子弧电流密度及离子气流场角度揭示了等离子电弧高热特性的原因。分析了等离子电弧的电场特性、离子气和保护气的流场特性以及不同焊接电流、离子气流量对电弧特性的影响。分析结果表明,离子气流量与电弧力成线性关系,保护气流量的选择导致的涡流大小影响电弧稳定性。图9表1参620084097继电保护设备柜体的螺栓焊接/王青阳//电焊机.-2008,38(2):74~75现在柜体表面大多采用静电喷涂,板面对螺栓焊接质量要求很高。采用螺栓闪光电阻焊代替焊条电弧焊焊接螺栓,其可靠性高,焊后对板面无烧伤,且能够提高产品质量、降低成本、提高功效。经试验证实完全可以满足产品质量要求。图1表420084098基于LabVIEW脉冲焊接过程稳定性评估系统/王卫彬…//电焊机.-2008,38(1):20~22GMAW-P焊接过程的稳定性对焊接质量有重要... 相似文献
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During stable keyhole plasma arc welding, the pilot arc and the transferred arc exist at the meantime, and the arcs can be considered as a composition of two parts inside and outside the nozzle, respectively. Under the mechanical constriction and thermal contraction effects, the inside arc has certain arc length, electron density and arc profile etc. inducing constant tungsten-to-nozzle voltage. However, the arc outside the nozzle diverges at about 5 degrees and has certain characteristics similar to the free arcs. The nozzle-to-workpiece voltage (NTWV) depends mainly on the length of the arc, which gets bigger as increasing of the weld penetration and keyhole size. The NTWV sensor is developed for monitoring NTWV in real time. The welding experiments are designed to get different penetrations and keyhole sizes. It is found that as the weld penetration and the keyhole size increase, NTWV also increases linearly. The NTWV signals can be used as the feedback variable in automatic control of keyhole plasma arc welding. 相似文献
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Tian Qing Li Xi Mou Yang Lu Chen Yu Zhang Yu Cheng Lei Jiu Chun Yan 《Science & Technology of Welding & Joining》2020,25(4):329-335
ABSTRACTImproving penetrability is a key issue in plasma arc welding (PAW). Increasing plasma energy is one way to improve arc penetrability. Gas focusing plasma arc welding (GF-PAW) platform is self-designed and developed. Role and action mechanism of focusing gas is initially studied. Focusing gas makes no obvious effects on arc pressure distribution and value. Focusing gas changes arc temperature distribution outer orifice, while focusing gas does not affect arc temperature distribution inner orifice. Focusing gas can constrict arc and arc energy increases 210?W with an increase in arc voltage of 1.4?V. GF-PAW can fully penetrate the whole work-piece while PAW can only partially penetrate the work-piece under welding current 150?A. GF-PAW can improve penetrability, and may increase welding speed, and has a potential application in manufacturing. 相似文献
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Aimed at plasma arc welding, a mathematic model was established according to the theory of magnetic fluid dynamics. The model was numerically analyzed by ANSYS software. The temperature, current density and plasma velocity distributions of normal arc had been simulated and compared with those of double arc. The results show that the appearance of double arc has made the temperature of the nozzle rise up to 5 000 K. The appearance of side arc could make the current density of the main arc decrease, and also make the maximal temperature of the arc reduce. 相似文献
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等离子弧切割技术因其高效稳定的工艺优势被广泛应用于工业领域. 文中以空气等离子弧为研究对象,通过COMSOL Multiphysics软件建立了喷嘴结构的二维轴对称有限元数学模型,并对电弧磁流体模型进行了优化. 基于磁流体动力学和电弧等离子体理论,选用等离子平衡放电多物理场接口,并确立了空气等离子电弧模型的控制方程和边界条件,实现对电弧模型的编译求解. 仿真结果表明,在引弧电流一致的条件下,随着环境压力的增加,电弧在温度分布和速度分布上均呈现收缩的态势. 基于3 MPa 高压焊接试验舱,搭建了高压环境等离子弧切割实验系统,通过对气路和非高频引弧电路的优化设计,实现了环境压力为0.1 ~ 0.7 MPa的稳定起弧. 并基于此开展了高压梯度下的等离子弧切割实验,并结合切割质量指标研究了环境压力对等离子弧电离行为的影响. 相似文献
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《Science & Technology of Welding & Joining》2013,18(6):423-430
AbstractThe effects of the process parameters of micro-plasma arc welding (micro-PAW) on the morphology and quality of stainless steel edge joint welds were investigated. Micro-PAW was applied on type 304 stainless steels to produce an edge joint weld. Welding experiments were carried out for various combinations of arc current, welding speed, arc length, shielding gas, and clamp distance, with all other operating conditions held constant. The experimental results indicated that the collimated shape of the low current plasma arc was mainly responsible for the low sensitivity of the weld morphology to variations in the nozzle standoff distances. The arc voltage increased with increasing quantity of added hydrogen in the argon shielding gas. It was also found that satisfactory edge joint welds can be formed using a clamp distance of 0.35 mm, and that the edge joint penetration on a 0.1 mm thickness stainless steel is about 60% of the clamp distance. 相似文献