Many countries are developing various mechanical cutting technologies to dismantle nuclear facility. However, most of mechanical cutting technologies have a problem like the degradation of tool life due to the Hard-Machining materials. To solve this problem, lab-scale test was performed with a Plasma Assisted Machining (PAM) technology and 25 mm of thickness Inconel 600 plate. Commonly, the strength of metals decreases by exposure at high temperature. And, previous study reported that strength of Inconel 600 is degraded above 500°C. This softening effect was applied to Inconel 600 cutting test. The optimal conditions such as the plasma torch power and the feed rate were determined by this study. As a result, the surface temperature of Inconel 600 was reached up to 500°C under the conditions which is 8.4 kW of plasma torch power and 150–250 mm·min−1 of feed rate. And it was confirmed that the tool life was improved under the conditions. In order to apply PAM for various Hard- Machining materials, it is necessary to investigate the softening temperature of Hard-Machining materials, the plasma torch power and feed rate.

• Jeongsu Jeong(Central Research Institute, Korea Hydro & Nuclear Power Company Limited, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon)
• Sunghoon Hong(Central Research Institute, Korea Hydro & Nuclear Power Company Limited, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon)
• Seoyong Choi(Central Research Institute, Korea Hydro & Nuclear Power Company Limited, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon)
• Mingyu Choi(Central Research Institute, Korea Hydro & Nuclear Power Company Limited, 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon) Corresponding author