EFFECT OF YTTRIUM ADDITION AND BETA HEAT TREATMENT ON HYDROGEN RESISTANCE OF ZIRCALOY-4-0.1%MO AT 600OC AND 800OC TEMPERATURES

• Main Author: Alfatar, Ajra
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/63206
• Institution: Institut Teknologi Bandung

Electrical energy is a source of energy that is widely used and needed by humans. Many equipment that uses electrical energy as a source of energy. So that the need for electrical energy will increase along with the increase in the number of human population. Nuclear Power Plant is one solution to this problem. With the characteristics of being environmentally friendly, economical, safe, non-volatile, and non-intermittent, making it one of the most promising power plants. One of the important components in a nuclear reactor is the nuclear fuel element cladding which plays an important role in determining the life of the reactor. The nuclear fuel cladding material commonly used is Zircaloy, but the use of Zircaloy for a long time will be susceptible to embrittlement due to hydrogen penetration in Zircaloy alloys. This research was conducted to determine the effect of adding yttrium and beta heat treatment to the hydration resistance and mechanical properties of Zircaloy-4-0.1%Mo-xY alloy (x=0 wt%; 0.5 wt%; 1 wt%). Series of experiments were carried out by smelting Zircaloy-4, molybdenum, and yttrium molded into Zircaloy-4-0.1%Mo-xY buttons using a DC arc melting furnace. Furthermore, the button is cut into two parts using a low speed precise saw cutting machine and one of them is beta heat treatment at a temperature of 1000oC for 2 hours then water quenching is carried out. As cast samples and beta heat treatment samples were tested for hydrogen charging containing 88% Argon - 12% Hydrogen at temperatures of 600oC and 800oC for 5 hours using a horizontal tube furnace. After testing for hydrogen charging, the samples were characterized using an optical microscope, XRD, SEM-EDS, and Vickers Hardness Tester. The addition of yttrium causes an increase in the precipitate which is thought to be ?-Y while increasing the hardness of the alloy in both as cast alloys and beta heat treatment. Beta heat treatment decreased the alloy hardness due to the formation of more ?-Zr phase. Hydrogen resistance can be increased by adding yttrium because it acts as a ?-Zr phase stabilizer. Similarly, beta heat treatment can increase hydrogen resistance with the same method, namely increasing the amount of ?-Zr phase so that the hydrogen solubility increases. The addition of 1 wt% Y to Zircaloy-4-0.1% Mo alloy with beta heat treatment showed the best hydrogen resistance with a thickness of 6.24 ?m at 600°C and 545.5 ?m at 800°C.