| OCR Text |
Show 5 possible to increase the high temperature strength of the radiant tubes by using more costly materials than steels of these alloys, the adoption of such materials would invite a large cost increase in the continuous annealing furnace, considering the large number of radiant tubes used in these facilities. For this reason, raising the heat resistance limit of radiant tubes by developing a new material cannot necessarily be considered advantageous. In contrast, considerable advantages can be expected if ~ T can be reduced without changing the radiant tube material,- because it would be possible not only to design a higher average temperature for the radiant tube, but also to reduce the stress originating in the temperature distribution. Likewise, positive effects can be expected if the stresses occurring in the radiant tube can be alleviated by optimizing the radiant tube support system and structural design. Based on the thinking described above,with the purpose of clarifying the cause of stress occurring in the radiant tube and behavior of radiant tube deformation was calculated by thermal stress analysis and the hot deformation was tested, and they were followed by verification of those characteristics. 2.3 Analysis of Radiant Tube Deformation Behavior Fig.3 (a) shows the stress occurring in the radiant tube immediately after its average temperature is raised from room temperature to 900°C |
