电弧超声对09MnNiDR钢焊接接头性能的影响  

Effect of arc-excited ultrasonic on the quality of the 09MnNiDR steel's joint

作　　者：张雁军[1] 李路明[1] 吴敏生[1] 

机构地区：[1]清华大学机械工程系,北京100084

出　　处：《福州大学学报（自然科学版）》2006年第4期533-537,共5页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50375080)

摘　　要：通过调制电弧激发出超声并应用于09MnNiDR钢的埋弧自动焊过程.采用常规焊接规范,并加入不同频率的电弧超声进行焊接工艺评定.金相分析表明,在电弧超声作用下,焊缝结晶组织明显细化,焊缝区针状铁素体增加.力学性能分析表明,接头的抗拉强度和低温冲击韧性等均有提高.尤其是在50 kHz超声作用下,焊缝区和热影响区-70℃冲击韧性值较未加入超声时分别提高了47%和82%,相应的断口SEM分析表明接头由解理断裂转变为韧性断裂.电弧超声还可强化传热,降低接头对焊接线能量的敏感性.实验证明电弧超声是提高低温钢焊接接头性能的一种有效的方法.A new method to excite ultrasonic by modulating electrical arc, namely arc - excited ultrasonic, was described and applied in the submerged arc welding process of 09MnNiDR steel. Qualifications of welding procedure were carried out with conventional welding parameters and arc - excited ultrasonic of different frequencies. Metallographic analyses show that the ultrasonic refines the grains notably. In the fusion zone, more acicular ferrite appears. Mechanical property tests indicate that ultrasonic also enhances tensile strength and impact toughness of the joints. Especially with arc - excited ultrasonic of 50 kHz, the values of impact toughness at - 70℃ are improved by 47 % in the fusion zone and 82 % in the heat affected zone compared with those without ultrasonic. Fractography by SEM shows that the fracture is changed from cleavage fracture without ultrasonic to gliding fracture with the effect of ultrasonic. Arc - excited ultrasonic can also accelerate heat transfer and reduce the line - energy sensitivity of welding. The experiments prove that arc - excited ultrasonic is an effective method improving quality of the joints of cryogenic steel.

关 键 词：焊接接头 电弧超声 低温钢 晶粒细化 冲击韧性 

分 类 号：TG409[金属学及工艺—焊接]