| Title |
Improvements of Impact toughness and Castability of Steel by the Addition of Calcium - Silicon |
| Authors |
이종수(Jong Soo Lee); 이경섭(Kyung Sub Lee); 김성만(Sung Man Kim); 소찬영(Chan Young So) |
| Abstract |
Effects of CaSi wire feeding on the impact toughness and the castability of Al-killed steel have been studied in full-scale industrial trials. The steel samples taken from a 40ton VAD vessel were subjected to the tensile and the Charpy impact tests for determining mechanical properties. In addition, the tundish nozzles through which Al-killed and Al-killed and Ca-treated steels had been cast were Xray diffractometrically examined. Calcium treatment of Al-killed steel remarkably increases the impact toughness of steel, which is considered to be due to uniformly distributed globular and small inclusions. In the Ca-added steel, the conversion of alumina into molten calcium aluminate inclusions substantially improves the steel castability. Since the aluminum retention is extremely small, it deems necessary to determine if an improved aluminum deoxidation could be obtained with the A1 wire feeding practice. |