| 摘要 |
PURPOSE:To increase the arc starting power in the preceding end part of a W electrode rod contg. thermion releasable materials and to improve the starting characteristics for arcing by etching the preceding end part of said electrode with an etching soln. thereby exposing the thermion releasable materials in the amt. larger than the atm. contained therein. CONSTITUTION:The preceding end part of a known W electrode rod contg. thermion releasable materials such as ThO2, ZrO2 or the like is immersed in an ethcing soln. such as an aq. alkali soln. of red prussiate of potash or the like, whereby said part is etched. By the etching, the W on the surface of the blank material for the electrode rod is etched and the thermion releasable materials in the amt. larger than the amt. contained beforehand therein are exposed on the surface thereof. As a result, the arc starting characteristics are improved, the arcing is stabilized, and the reliability of welding and the quality of weld zones are improved. Further, it is possible to extend the working time for welding by increasing the execution times of welding. |
