Fe-Base의 SNCM강에 대한 열처리 조건에 따른 기계적 성질에 관한 연구 : 열처리 조건에 따른 기계적 성질에 관한 연구 = A Study on the Mechanical Properties of Fe-Base SNCM Steel as a Function of Heat Treatment Conditions

국문 초록 (Abstract)

Abstract (※국문초록을 영문으로 번역) A Study on the Mechanical Properties of Fe-Base SNCM Steel as a Function of Heat Treatment Conditions KIM, KI HYOUN Advisor : Lee, Seung Hee Department of Metal & Chemical Materials Engineering Graduate School of Nambu University In this study, a new alloy steel (C: 0.45–0.50%, Ni: 3.9–4.05%, Cr: 1.43– 1.46%, Mo: 0.75%, V: 0.51–0.53%) was developed to improve the impact toughness and wear resistance of blades used for cutting steel scrap. The performance of the developed alloy was compared with that of conventional blade materials such as SKD11, SKD61, and STD11. The developed alloy was designed to enhance toughness and impact resistance through nickel (Ni) addition, while chromium (Cr) and molybdenum (Mo) additions provided improved hardenability and heat resistance. Furthermore, the fine vanadium (V) carbides contributed to grain refinement and enhanced wear resistance. Chemical composition analysis, Charpy impact testing, evaluation of impact energy variation with austenitizing temperature (950–1100 °C), surface hardness measurement, microstructural observation (optical and SEM), and grain size assessment (ASTM E112) were conducted. The results showed that the developed alloy exhibited the highest impact absorption energy at 1050 °C austenitizing temperature, outperforming SKD11 and STD11, and displayed approximately 25% higher toughness than SKD61. The microstructure consisted of uniform tempered martensite, and the dispersion of V carbides led to grain refinement and increased hardness. In conclusion, the developed Fe-based alloy demonstrated excellent durability and cutting performance under high-temperature impact conditions, suggesting that it has strong potential to replace SKD11 and STD11 as a material for steel scrap cutting blades.

목차 (Table of Contents)

• 표목차 ⅲ
• 그림목차 ⅳ
• 국문초록 ⅴ
• I. 서 론 1
• 1. 연구 배경 및 목적 1
• 2. 연구 범위 및 방법 2
• 3. 기존 연구의 고찰 3
• 4. 블레이드(컷터기)의 용도 및 특성 7
• 5. Fe-Base의 SNCM강의 합금원소의 역할과 기능 9
• II. 실험 방법 11
• 1. Fe-Base의 SNCM강의 화학적 성분 시험11
• 2. Fe-Base의 SNCM강의 충격 시험11
• 3. Fe-Base의 SNCM강의 고용화(Austenitizing) 온도에 따른 충격값, 표면경도, 조직, 결정입도 시험 12
• III. 실험 결과 및 고찰 13
• 1. Fe-Base의 SNCM강의 화학적 성분 시험 결과 및 고찰 13
• 2. Fe-Base의 SNCM강의 충격 시험 결과 및 고찰 14
• 3. Fe-Base의 SNCM강의 고용화(Austenitizing) 온도에 따른 충격값, 표면경도, 조직, 결정입도 시험 결과 및 고찰 15
• Ⅳ. 결론 22
• 참고문헌 25
• Abstract 26