中文摘要：

将超声激励源对氩弧焊（GTA）电源调制以激发出电弧超声,通过电弧与工件的自耦合作用,将其引入到中国低活化马氏体钢（CLAMs）钢的焊接中,超声-GTA焊接电流、超声激励电压及组合依据经验恰当选取.试验结果及其对比分析表明：电弧超声引入可以有效地改善焊缝的组织与性能,通过选取适合的焊接-超声工艺参数组合,可以使CLAM钢焊缝区马氏体板条束的分布及尺寸更加均匀细密,碳化物弥散分布,焊缝冲击性能明显提高,最高可提高80%.在电弧超声振动搅拌和热量输入的双重作用下,随着激励电压的增大,焊缝的冲击性能呈先上升后下降的趋势.在控制总焊接热输入量的条件下,适当的增强激励电压可以得到较好的冲击力学性能.

英文摘要：

The GTA-ultrasonic,which was stimulated by modulation of ultrasonic excitation to the gas tungsten arc welding（GTAW） source power,was used to weld China Low Activation Martensitic steel（CLAMs） by coupling interaction between arc and workpiece.According to previous experiences,wel-ding current,proper excitated voltage and their combination were selected.The experimental results,comparison analysis show that the microstructure and the mechanical properties of CLAMs weld are ame-liorated remarkably by GTA-ultrasonic.By appropriate combination of GTA-ultrasonic parameters,martensite laths bundle of joints become dense with fine distribution of precipitated carbides.The impact toughness of weld joint is improved markedly with maximum of 80%.Under the combined effect of ar-cultrasonic and heat input,the impact toughness of weld joint increase a trend first and then decrease with the increasing of excitated-voltage.By controlling the quantity of welding heat input,high impact toughness can be achieved by appropriate enhancement of excitated-voltage.