Abstract
The material characteristics of steels are different according to the manufacturing period. In the maintenance of many aged steel railway bridges, it is important to understand the material characteristic of the aged steels. In this study, the material tests were executed for steel material of the various manufacturing period to investigate the material characteristic. In addition, the influence of a given prestrain on the strength and the impact toughness of the aged steels were clarified.
As a result, it was found that the impact toughness of the aged steels decreased as increasing of the given prestrain than that of the recent steels.
