手工电弧焊与CO2气体保护焊焊缝成形特征研究

采用手工电弧焊与CO2气体保护焊对Q235钢板进行表面堆焊，研究了两种焊接方法的焊缝成形特征．结果表明，虽然手工电弧焊是气渣联合保护，有利于焊缝成形，但手工操作使得焊接速度难以保证匀速，导致焊缝表面粗糙，焊缝弯曲不平直；并且由于药皮焊条直径粗，导致手工电弧焊热影响区宽．而细丝CO2气保焊由于形成稳定的熔滴过渡，使得焊缝表面波纹细致、美观，焊缝平直，热影响区窄．CO2气保焊能精确控制焊接规范，可通过调节焊接规范来获得良好的焊缝成形，手工电弧焊不能精确控制焊接规范，不利于得到成形良好的焊缝．

Research on Welding Seam Formation Characteristics of Manual Arc Welding and CO2 Gas Protection Welding

The welding seam formation characteristics of manual arc have been researched by the experiments of bead welding on Q235 welding and CO2 gas protection welding steel surface by using the two welding methods. The results show that the gas and slag union protection arc welding is benefit to welding seam formation of manual arc welding; but the manual operation can not get the steady welding speed with the result that the welding seam surface of manual arc welding is rough and its welding seam is not straight. Moreover the heat affected zone of manual arc welding is wide because of the thick electrode diameter. However the welding seam surface of CO2 gas protection welding is exquisite; its welding seam is straight and its heat affected zone is narrow under steady droplet transfer of thin wire CO2 gas protection welding. CO2 gas protection welding can accurately control welding specification and can obtain good welding seam formation by adjusting welding specification. Manual arc welding can not accurately control welding specification and go against obtaining good welding seam formation.