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pISSN : 1598-706X / eISSN : 2288-8381


한국주조공학회지 (14권6호 566-575)

The Effects of Centrifugal Casting Conditions on the Structure and Mechanical Properties in Fabrication Development of Super Heat-Resisting Steel Pipe of HP Alloy Modified with Nb

Nb을 첨가한 HP 초내열강관의 제조개발에 필요한 원심주조 조건이 조직과 기계적성질에 미치는 효과

Sang-Ho Choi

Dong-Yang Tech College.


The effects of varying the pouring temperature and the die preheating temperature in producing centrifugally cast HP alloy modified with Nb was evaluated on the basis of the resultant macrostructure, microstructure and hardness of these castings. Increased die preheating temperatures and pouring temperatures resulted in an increase in the thickness of the columnar dendritic zone, the primary and secondary dendrite arm spacing and the thickness of the zone of porosity at the casting I.D.(inner diameter). Lower die preheating temperature and pouring temperatures result in increased grain fineness and an increased zone of equiaxed grains. A higher hardness was achieved toward the casting O.D.(outer diameter) compared to the casting I.D., attributable to alloy segregation toward the casting I.D. and segregation differences resulting from reduced solidification cooling rates toward the casting I.D. Also, a higher hardness was realized at the cold end of the casting attributed to a more uniform distribution of carbides.