Fe-Cr-Al계 합금 빌렛의 상온 표면균열 원인에 관한 연구

김상원; 박종혁; 김인배; S.W. Kim; J.H. Park; I.B. Kim

Korean Journal of Materials Research, Vol.14, No.1, 19-27, January, 2004

DOI10.3740/MRSK.2004.14.1.019 Export Citation

Fe-Cr-Al계 합금 빌렛의 상온 표면균열 원인에 관한 연구

Study on the Origins of Surface Cracks at Room Temperature in Fe-Cr-Al Alloy Billets

김상원^†, 박종혁¹, 김인배¹

포항산업과학연구원 부품신소재연구센터 신금속연구팀
¹창원특수강 기술연구소

S.W. Kim^†, J.H. Park¹, and I.B. Kim¹

New Materials & Components Research Center, Research Institute of Industrial Science & Technology(RIST), Korea
¹Technical Research Laboratories, Changwon Specialty Steel Co., Ltd., Korea

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Metallurgical and mechanical experiments were performed to explain unexpected surface cracks encountered in fabricating ground rolled-billet of Fe-Cr-Al alloys at room temperature. The toughness of these alloys containing between 220 and 236 ppm (C+N) has been assessed using notched-bar impact tests. According to our results, with a larger grain size, a higher interstitial content of (C+N) or a smaller size of precipitates, ductile to brittle temperature(DBTT) increased and absorbed energy decreased at room temperature. These results suggest that the surface cracks at room temperature stem from a poor resistance to brittle fracture, due to dislocation movement by the finely dispersed carbides within grains under the condition of higher (C+N) content.

Keywords:Fe-Cr-Al allovs;embrittlement;toughness;DBTT

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[2] Metals Handbook Ninth Edition, 3, p.640, Metal park, Ohio (1980) (1980)

[3] Yamada S, Oosawa H, Denki Seik, 38(3), 136 (1967)

[4] Case SL, Van Horn KR, Aluminum in Iron and Steel, 265 (1953)

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[16] Plumtree A, Gullberg R, J. Test. Eval., 2(5), 331 (1974)