Abstract
The effects of the width of the "Synthetic Impact Test" specimen are investigated. Width of the specimen are changed from 0.4cm to 1.0cm. By these tests the brittle parts of the Heat-affected zone can be recognized from the appearences of the fractures. As the results of these experiments followings are known:
1) The impact value changes approximately linearly with the width of the specimen when the notch shape is not so severe.
2) In this impact test the side of parent plate creavage first, so that the brittle range of the Heataffected zone can be recognized.
