저탄소 주강의 고온연성에 미치는 유화물의 영향

Abstract

The influence of sulfide inclusions on the hot ductility of low carbon steel castings was studied by hot tensile test using Gleeble test equipment. The Gleeble heating tensile test and cooling tensile test was performed at 1340, 1360, 1380 and 1400 ℃, respectively. On the heating tensile test, test temperature was gradually higher, it was found that the ductility fracture was transformed into the brittle fracture, the hot ductility decreased. On the other hand, on the cooling tensile test, the ductility fracture and the brittle fracture were observed at the same test temperature, the hot ductility was . The results from microstructure on the cooling tensile specimens, sulfide inclusions were found in grain boundary in case of brittle-fractured specimen, in grain in case of ductile-fractured specimen. Components of sulfide inclusions analyzed by EPMA. The results show that sulfide inclusions in grain boundary had FeS, those in grain had MnS.