As product diversity increases and product life cycle gets shorter, lead time reduction and manufacturing cost saving of die & mold are getting important in machinery, automotive, and electronics industries. To develop a novel free-machining die & mold steel, we try to modify the chemical compositions of AISI P20 mold steel by adding boron, nitride, and sulfur. After making three types of mold steels which are base metal of AISI P20 mod., boron and nitrogen added, and boron, nitrogen, and sulfur added to the base metal. Milling tests are carried out using TiN, TiCN, and TiAlN coated WC end-mills under various cutting conditions. Boron and nitrogen added steel machined by TiN coated tool shows the most excellent tool wear and surface roughness characteristics. The results might come from BN inclusions in base metal acting as a stress concentration source and lowering strain resistance during cutting process. The relationship between tool wear and surface roughness are also discussed including feed rate effects.

ABSTRACT
 1. 서 론
 2. 실험 장치 및 방법
  2.1 시험편의 제작
  2.2 실험 장치 및 가공 조건
 3. 실험 결과 및 분석
  3.1 공구 마모
  3.2 공구 코팅별 공구 마모
  3.3 시험편 별 표면거칠기
  3.4 절삭 조건 별 표면 거칠기
 4. 결 론
 References

• 황성국(Chonbuk National Unversity) | Sung-Kug Hwang Corresponding Author
• 이정환(Chonbuk National University) | Jeong-Hwan Lee
• 류시형(Chonbuk National University) | Shi-Houng Ryu