| 摘要 |
PURPOSE:To stabilize the arc with weak pulse base currents by melting the surface of materials to be treated extremely slightly by the arc generated by the first pulse peak current and holding the arc by utilizing the metallic vapor pressure increased by this. CONSTITUTION:The arc 2 is generaged by the arc current which is increased instantaneously by a pulse TIG welding machine and is smaller than this in average between a tungsten electrode 1 and ferrous materials 3 to be treated, whereby the materials 3 are melted and heated and bead parts 4 are formed. At this time the materials 3 are melted in such a way that the volume ratio between the molten area and the area 5 heated to above the Ac1 transformation point is the same or the latter is larger, thence the materials are cooled to harden. Thereby, the stable and fine patterns are heated by the arc 2. |
