| 摘要 |
PROBLEM TO BE SOLVED: To prevent melt-down of non-solidified metal at a joining part by starting the joining in specific range from the one end of the joining parts of a preceding steel material and a succeeding steel material and completing the joining in specific range from the other end joining parts. SOLUTION: In the running joining of the preceding steel material and the succeeding steel material for hot-continuous rolling, at the time of joining with a laser beam welding method or an arc welding method as the joining means, the starting point and the completing point of the irradiation of laser beam or the discharge of arc are made to the range of 10-20mm from the both ends of the joining part. By this method, the flow-out i.e., the melt-down of the non- solidified metal at the end parts of the joining parts is prevented by enlarging heat absorbing quantity of the base materials at the end parts of the joining parts and dispersing the laser beam energy or the arc energy. Further, the breakage in a finish rolling process and the deterioration of the quality of the steel plate obtd. with the finish-rolling can be prevented. |
