| Title |
Research Paper - Solidification - : Microstructure Evolution of AISI 430 Stainless Steel Strip by Twin - Roll Strip Caster |
| Authors |
최주태(Ju Tae Choi); 김용희(Yong Hee Kim); 오규환(Kyu Hwan Oh); 나형용(Hyung Yong Ra); 정성인(Seong In Jeong); 윤종칠(Jong Chil Yoon) |
| Abstract |
AISI 430 stainless steel strip was fabricated by laboratory scale twin-roll strip caster. Microstructure of ascast strip consists of ferritic α matrix, (Fe,Cr)_(23)C_6 carbides and lath martensite at grain boundary, observed in transmission electron microscopy. Martensite was transformed from retained austenite at grain boundary due to rapid cooling of strip casting. The martensitic formation can be suppressed by the slow cooling after roll nip point. The lower value of hardness at the strip surface was obtained because primary ferrite remained due to higher cooling rate. As it goes from center region to edge region, the solidification end point is located above average height and the white band zone at the central layer become wide. The zone of negative segregation results from squeezing out near the central layer of the liquid which has high phosphorus and sulfur content. |