Welding deformation is complexly affected by different factors, and that is predicted to depend on the skills of welding operatives, being affected by welding parameters such as the welding current, arc voltage and welding speed. It is therefore desirable to treat welding deformations statically. This paper describes an investigation into the statistical properties of the welding parameters, transverse shrinkage and angular distortion when welding operatives having specified skills are engaged in semi-automatic MAG welding of butt welding joint with backing plate. The results obtained may be summarized as follows.
(1)The distribution characteristics of the welding heat input, product of welding current and voltage, and the reciprocal of welding speed are clarified, besides and they conform to a normal distribution.
(2)The distribution characteristics of the transverse shrinkage and angular distortion have been made clear. And they conform to a normal distribution are clarified.
(3)95% confidential interval of mean valus and standard deviation of population in the transverse shrinkage and angular distortion when welding operatives obtaining license SN-2F in JIS Z 3841 are engaged in semi-automatic MAG welding of butt welding joint with backing plate are estimated.
