Daihen Corporation

Shoji Harada

Toshiaki Nakamata

Tomoyuki Ueyama

Toshimitsu Doi

Hiroshi Nakai

Ichiro Matsumoto

Shunichi Ogawa

Masuo Shibata

An MAG arc welding method and apparatus is capable of achieving a welding bead in a regular ripple pattern or in a suitable sectional form. The welding power source generates the first welding current I1 and a second welding current I2 larger than the first welding current. The wire melting speed is changed by switching between the first and the second welding currents. The welding method or apparatus according to the invention generates the first arc length more than 2 mm and the second arc length more than the first arc length and switches between both arc length at a switching frequency F of 0.5 to 25 Hz. The ratio of the second to the first welding currents is made to be in 1.03 to 1.20. In addition to a welding method to change the arc length by switching the first and the second welding currents at a constant wire feeding rate, the present welding method makes it possible to carry out the lap welding or butt welding even when there is a large gap. The large gap requires a large amount of molten metal which is prepared by increasing the wire melting speed caused by an increase in the wire feeding rate by 5 to 20%. The resultant reinforcement has a beautiful appearance.

MAG arc welding apparatus

Method of MAG arc welding

Method of MAG arc welding and welding apparatus

Growing community of inventors

Osaka, Japan

Shoji Harada