Abstract
This study investigates the effect of electron beam welding (EBW) on SA508 Gr.3 Cl.1 Mn-Mo-Ni low alloy steel, focusing on changes in the microstructural and mechanical properties of the weld and heat-affected zone (HAZ) under various post-weld heat treatment (PWHT) conditions. The rapid cooling inherent in the EBW process led..... More

Abstract
This study examines the thermal aging behavior and associated changes in mechanical properties of austenitic stainless steel welds (ASSW) used within reactor vessel internals (RVI). ASSW specimens were fabricated employing the Gas Tungsten Arc Welding (GTAW) technique, adhering to the welding procedure specifications for RVI, and were thermally aged at..... More

Abstract
To apply the leak-before-break (LBB) concept to the main steam line piping of nuclear power plants, the use of SA508 Gr.1A low-alloy steel is being considered. To increase the LBB safety margin, it is essential to improve the strength and toughness of the material. In this study, intercritical heat treatment..... More

Abstract
To analyze the effects of intercritical heat treatment on the temper embrittlement of SA508 Gr.4N steels, two model alloys with different phosphorus (P) contents were fabricated. Each sample was heat treated by applying a conventional heat treatment process (quenching-tempering) with/without an intercritical heat treatment process (IHT) and a step-cooling heat..... More

Abstract
The creep properties of Alloy 690, used as a steam generator tube material in nuclear power plants, were evaluated at 650°C, 750°C, and 850°C. The parameters of creep life prediction models were derived using the Larson-Miller (LM), Manson-Haferd (MH), and Orr-Sherby-Dorn (OSD) models, to use as mechanical properties under a..... More

Abstract
The small punch (SP) test is one of the small specimen test techniques, and standardization of the SP test method for evaluating the mechanical properties of metallic materials is in progress. In this study, the impact transition temperature of reactor pressure vessel steels (RPV) in nuclear power plants was estimated..... More

Abstract
In this study, the effects of microstructural variations in heavy-section reactor pressure vessel (RPV) steels on tensile and Charpy impact properties were investigated. Two PRV blocks, OPR1000 and APR1400 (ORV, ARV) were taken from the archive materials used in Korea standard nuclear power plants. Test specimens were sampled from five..... More