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Vol.56, No.7, 499 ~ 505, 2018
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| Title |
| Effects of Si on the Characteristics of FCA Multi-Layer Weld Metal with 460 MPa Yield Strength Grade Steels for Ships and Marine Structures |
| 김종식 Jong-sig Kim , 이명수 Myeong-soo Lee , 정종민 Jong-min Jung , 최한글 Han-geul Choi , 정상훈 Sang-hoon Jeong , 강창룡 Chang-yong Kang |
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| Abstract |
| This study investigated the effect of Si on the characteristics of FCA multi-layer weld metal with 460 MPa yield strength grade steels for ships and marine structures. The effect on microstructure was evaluated by tensile, charpy impact and CTOD testing of 4 FCAW welds containing various C and Si contents. C content affected weld metal properties depending on Si content, microstructure, strength and impact value. With lower C content, strength and impact value increased when Si content was reduced, because of higher AF volume fraction. With higher C content, those properties were little affected by Si content. These phenomena indicate that C affects phase transformation more than Si. The CTOD value was higher with lower Si and higher C content. This was interpreted to mean that a lower volume fraction of not only PF, FS but also the M-A phase, can affect crack initiation sites, due to higher C and lower Si contents.
(Received April 5, 2018; Accepted May 16, 2018) |
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| Key Words |
| impact toughness, strength, CTOD, microstructure. FCAW, Si |
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