It was previously reported that there was possibility for excellent improvement of the creep strength of TIG-welded joints by using the filler metals contained minor elements such as B, Zr and REM. The twenty-two laboratory heats of Hastelloy X filler metals contained minor elements of various amount lebels were produced for the weldability studies in this work, and mechanical properties of weld metals and weld crack sensitivity by TIG-welding method were examined. The main results are as follows:
1. A ductility of weld metals by using the filler metals contained minor elements was more excellent than that by using the filler metals without any minor element on the tensile test at elevated temperature.
2. Some fissures were observed in weld metal on the fissures bend test for welded joints by exceeding a suitable amount lebel of addition of minor element.
3. The filler metals contained minor element did not so much influenced on the weld hot-crack sensitivity, and there was no trouble in the practical welding performance using such filler metals.
4. A possibility was found that remarkable improvement of the creep strength of Hastelloy X TIG-welded joints was performed by using the filler metals contained minor elements, but its amount of addition had to be controlled sufficiently to keep the good weldability of Hastelloy X.
