It has been presented the results of the technological investigation into the innovative GMA welding method with the use of variable polarity AC during welding of HCT 600X ZF 100 RBO high strength steel. The results of mechanical testing and metallographic examination of welded joints have been given. The influence of electrode negative (EN ratio) on the quality of welded joints and particularly on the fusion depth and HAZ width has been analyzed. The prospective fields of commercial application of innovative welding techniques have been discussed.