双频调制脉冲TIG打底焊电弧-熔池行为分析  

Analysis of Arc-weld Pool Behavior of Double-Frequency Modulated Pulse TIG Root Pass Welding

作　　者：张刚[1] 徐梓龙 石玗[1] 朱明[1] 樊丁[1] ZHANG Gang;XU Zilong;SHI Yu;ZHU Ming;FAN Ding(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050

出　　处：《机械工程学报》2023年第12期245-252,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51905245);甘肃省自然科学基金(20JR5RA455,21JR7RA202);甘肃省重点研发计划(20YF8GA054);中科院“西部之光”青年学者人才支持计划;陇原青年创新创业人才;兰州理工大学红柳优秀青年人才扶持计划资助项目。

摘　　要：为提高中厚板核容器焊接制造效率、质量稳定性及满足无衬板打底单面焊双面成形的工艺新要求,设计小角度、大钝边Y型坡口平板对接焊接结构,建立双频调制脉冲TIG焊接试验控制系统,开展多组低频脉冲和双频调制脉冲焊接工艺对比试验,获得坡口角度60°、钝边5mm的试板对接可靠打底单面焊双面成形焊缝。进一步研究分析双频调制脉冲电弧、熔池动态行为变化及熔池表面温度场的演化规律,探究讨论双频调制脉冲电流作用下焊缝熔深增加的原因。结果表明,双频调制脉冲电弧因高频脉冲电磁压缩作用具有更高的能量密度和更强的电弧穿透力,使熔池底部极易形成液态金属薄膜并穿透形成熔孔;同时,双频调制脉冲电弧减弱了熔池顶底部液态金属能量波动,增强熔池热惯性,有效降低熔池凝固速率,增加了焊缝熔深,为熔池单面焊双面成形提供良好的热力动态平衡条件。An improved double frequency modulated pulse TIG process was applied to deeply weld the root pass metal with low angle and large root face for increasing the production efficiency and weld bead quality as well as meeting the new requirements of one-sided welding with double-sided formation in nuclear vessel made with medium-tick plates.The experimental control system was established,and multi-repeatable experiments were conducted with low frequency and double frequency modulated pulse current,respectively.A reliable one-sided welding with double-sided formation was successfully achieved with 60 degree and 5 mm thick root face.The increased mechanism of the weld penetration was also explained by analyzing the arc and weld pool behavior combined with the temperature filed evolution of the weld pool surface.The results indicated that the modulated pulse arc has a higher energy density and pierced force,easily piercing the liquid weld metal film and forming the keyhole.The variation of energy in the weld pool changes lower,and the thermal inertia of the weld pool is enhanced.The solidification velocity is also effectively decreased,the weld penetration,thus,is increased.Therefore,the added high frequency pulse current provides a good dynamic thermal-force balance for achieving a sound one-sided welding with double-sided formation.

关 键 词：脉冲TIG 电弧形态 熔池 单面焊双面成形 打底焊 

分 类 号：TG444[金属学及工艺—焊接]