Abstract
This paper reports the effect of post-heating on the bending test result in manual arc welding of the rail joint when the joint type, the electrode type, and prenehting conditions are properly determined.
The results are summarized as follows:-
1. A satisfactory joint can be obtained when low hydrogen electrodes (E 7016, E 8016) are applied to shovel shape joints, preheating bases and webs of rails at 400°C, and head at 200°C. And applying the post-heating at 600°C for 30min. directly after welding has an appreciable effect on improving joint ductility.
2. Statistically no significant difference could be observed between the breaking load of as welded and of post-heated weld joints in head up bending test with 1 m. span length, but the bending deflection and the fracture energy obviously show the excellence of the post-heated weld joint. Therefore, it is proper to adopt the bending deflection or the fracture energy as a criterion of the bending test in addition to the breaking load.
3. As a result of this experiment, the authors propose to adopt the fracture energy over 3000 kg-m or the deflection over 45mm in addition to the breaking load over 90 tons as the tentative standard of manual arc weld joint of 50 kg/m P. S. rail.
4. C% and Ceq% of the rail materials seem to have a considerable effect on the bend ductility of the weld joints.
