| 摘要 |
PURPOSE:To prevent the generation of cracking in a covering owing to drying it the stage of drying a coated arc welding electrode with low and high temp. treatments by providing a preliminarly drying stage before the low temp. drying stage and subjecting the electrode to preliminary drying under a specific condition. CONSTITUTION:A coated arc welding electrode 1 is placed on a belt conveyor 2 and is first subjected to preliminary drying in a preliminary drying stage 5 and is thereafter subjected successively to a drying treatment by a low temp. drying stage 3 and a high temp. drying stage 4. A double logarithmic graph of a drying time and a drying temp. is made in this stage 5 and the preliminary drying is performed in the initial period of the drying stage for the at the drying time and drying temp. in the region enclosed with the quadrilateral ABCD formed by the point A for 10sec, 1,000 deg.C, the point B for 10sec, 600 deg.C, the point C for 200sec, 100 deg.C and the point D for 600sec, 100 deg.C. Only the surface of the covering of the electrode 1 is thus uniformly solidified, by which the cracking in the covering is prevented. |
