티타늄에 의한 페라이트계 스테인레스 주강의 분산강화

Abstract

SUS 430 강에 Mo을 2wt.% 첨가하여 고용강화 시키고 티타늄과 탄소를 첨가 시켜 분산강화한 주강의 고온강도를 측정하였다. 티타늄 탄화물의 형상은 구상이었으며 2wt.% Ti을 첨가하였을때 탄화물의 표면밀도가 7×105개/㎠로 최대이었고 탄화물의 크기는 평균 0.5∼3.0㎛ 이었다. 2wt.% Ti을 첨가시킨 강이 800℃에서 인장강도 값은 8.7㎏/㎟이고 파괴신율은 45%로서 고온강도와 인성이 가장 우수 하였다.

High temperature tensile strength of SUS430 steel strengthened by addition of Mo and Ti as alloying elements has been measured. The morphology of titanium carbides showed spherical in shape and their distribunion depends on the amount of alloying elements. Maximum density of 7×105/㎠ has been observed in the alloy containing 2.0 wt.% titanium and 0.5 wt.% carbon as alloying elements. The size of carbide particles is in the range of 0.5 to 3.0 ㎛ and the high temperature tensile strength of this alloy was the highest among the alloys tested in this research. The fracture mode of the alloys containing alloying elements less than 2.0 wt.% Ti showed intercrystalline fracture at room temperature, while the alloys containing higher than 2.0 wt.% Ti showed transcrystalline fracture. All of the alloys showed ductile rupture mode at elevated temperature.

High temperature tensile strength of SUS430 steel strengthened by addition of Mo and Ti as alloying elements has been measured. The morphology of titanium carbides showed spherical in shape and their distribunion depends on the amount of alloying elements. Maximum density of 7×105/㎠ has been observed in the alloy containing 2.0 wt.% titanium and 0.5 wt.% carbon as alloying elements. The size of carbide particles is in the range of 0.5 to 3.0 ㎛ and the high temperature tensile strength of this alloy was the highest among the alloys tested in this research. The fracture mode of the alloys containing alloying elements less than 2.0 wt.% Ti showed intercrystalline fracture at room temperature, while the alloys containing higher than 2.0 wt.% Ti showed transcrystalline fracture. All of the alloys showed ductile rupture mode at elevated temperature.