| 摘要 |
PCT No. PCT/JP91/00505 Sec. 371 Date Dec. 18, 1991 Sec. 102(e) Date Dec. 18, 1991 PCT Filed Apr. 17, 1990 PCT Pub. No. WO91/16167 PCT Pub. Date Oct. 31, 1991.In a method of automatically welding rails, welding of bottom portions of the rails is carried out as root pass welding of a first layer according to CO2 gas shielded arc weld technique, and as continuous multilayer welding of layers above the first layer according to CO2 gas shielded arc weld technique without discontinuing the welding of a second layer and upper layers. In welding of ankle portions (R2) of the rails, a flux is rapidly added to promptly shift to electroslag weld. Then, welding is conducted to head surfaces (R5) of the rails by continuing electroslag weld technique. This automatic welding method enables high efficiency field welding of rails, obviating the need for any complicated switching operation of the electric power source and use of several kinds of welding materials. |
