In recent years, industrial demands for superior mechanical properties of powder metallurgy steel components with low cost are rapidly growing. Sinter hardening that combines sintering and heat treatment in continuous one step is cost-effective. The cooling rate during the sinter hardening process dominates material microstructures, which finally determine the mechanical properties of the parts. This research establishes a numerical model of the relation between various cooling rates and microstructures in a sinter hardenable material. The evolution of a martensitic phase in the treated microstructure during end quench tests using various cooling media of water, oil, and air is predicted from the cooling rate, which is influenced by cooling conditions, using the finite element method simulations. The effects of the cooling condition on the microstructure of the sinter hardening material are found. The obtained limiting size of the sinter hardening part is helpful to design complicate shaped components.

• 박효욱(포항공과대학교, 신소재공학과) | Hyo Wook Park
• 주수현(포항공과대학교, 항공재료연구센터) | Soo-Hyun Joo
• 이언식(포항산업과학연구원, 재료공정연구소) | Eon Sik Lee
• 권기혁(포항산업과학연구원, 재료공정연구소) | Ki Hyuk Kwon
• 김형섭(포항공과대학교, 신소재공학과, 포항공과대학교, 항공재료연구센터) | Hyong Seop Kim Corresponding Author