| Popis: |
In dissimilar weld joints such as ferritic steel and austenitic steel, properties of heat affected zone are by heat treat ment, but it accelerates diffusion of carbon producing decarburized and carburized zone around the weld bond. Then, we studied relations between conditions of post weld heat treatment and the characteristic of decarburized zone by means of dissimilar weld joint consisting of 21/4 Cr-1 Mo, 0.5 Mo and D309 Mo steel. Some of the results are summarized as below.(1) Width of decarburized zone in weld bond was calculated from heating temperature and time according to diffusion formula.(2) Properties of weld bond was much affected by the heating temperature than the holding time. Sharpy impact energy was lowered at 700°C×3hr in 21/4-1 Mo and 650°C×8hr in 0.5 Mo. |
