高压环境下电弧电特性及管道焊接工艺的研究

Arc characteristic and welding technology for pipeline under high ambient pressure

利用自制的高压干法水下焊接模拟试验平台,首次研究了高压空气环境下的GTAW电弧电特性,研究表明:随着环境压力的升高,气体密度增大,电离度降低,弧柱电场强度增加,导致电弧静特性曲线上移。利用多元线性回归方法,建立了高压空气环境下的电弧电压数学模型,并在此基础上进行了高压模拟管道焊接工艺试验。研究表明,随着环境压力的增大,焊接电流减小,Ar流量增大。在0.1,0.3,0.5和0.7MPa压力下,选用合理的焊接工艺参数,对于X56管线钢,均获得单面焊双面成形的良好效果。

Using the homemade hyperbaric underwater welding simulation experiment equipments, the characteristics of GTAW arc under the high pressure atmosphere surroundings are studied for the first time in the paper. The research indicated that along with the hoist of environmental pressure, the gaseous density is increscent, the degree of ionization is depressed, the electric field intensity of arc column is increscent, the static characteristic curve of electric arc move upwards. After the air pressure boosting, not only the electric field intensity of arc column is increscent, the energy of arc column is enhanced, but also the section of electric arc is shrinked, the density of energy is augmented, so the brightness of electric arc is swelled. Using the means of multiple regression,the mathematical model of arc voltage under the high pressure atmosphere surroundings is founded. The simulation welding experiment of X56 pipeline steel under different pressure s such as 0.1, 0.3, 0.5, 0.7 MPa has been done, and the good effect of one-side welding with back formation is acquired through the choice of reasonable welding parameters.