| Title |
Pesearch Paper / Mechanical Behaviors : Alloy Designing Study for Improving Mechanical Properties of SA 508 Steel for Nuclear Reactor Pressure Vessel |
| Authors |
김상호(Sang Ho Kim),임영록(Young Roc Im),이성학(Sang Hak Lee),이후철(Hu Chul Lee),오용준(Yong Jun Oh),홍준화(Jun Hwa Hong) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
This study is concerned with the development of low-alloy steels for nuclear reactor pressure vessel by investigating the effects of alloying elements on mechanical properties of base metals and heat affected zones(HAZ`s). Four kinds of steels with different alloying elements were fabricated by vacuum-induction melting and heat treatment, and their tensile properties and Charpy impact toughness were evaluated. Microstructural analyses indicated that coarse M₃C-type carbides and fine M₂C-type carbides were precipitated along lath boundaries and inside laths, respectively. In the steels having lower carbon content and higher molybdenum content, the amount of fine M₂C carbides greatly increased, while that of coarse M₃C carbides decreased, thereby leading to the improvement of tensile properties and impact toughness. Their simulated HAZ`s also had sufficient impact toughness after post-weld heat treatment. These findings suggested that low-alloy steels with high strength and toughness could be processed by reducing the amount of carbon and manganese and by raising the amount of molybdenum. |