Abstract
The purpose of this study is to clarify the actual condition and the structure of cold shut in 13%Cr steel casting. The materials used in these experiments were small blade-shape specimens, which were molten by high frequency induction furnace and poured into investment process mold at 1570°C.
On the surface of the cold shut, there was an oxide film which contained Al2O3, SiO2 and MnO. The boundaries between the oxide film and the fine ferrite surface layer were rich in Cr. The cold shut was along grain boundaries. Sulfur segregation such as in the hot tear did not exist. The fracture surface teared from the end of the cold shut demonstrated a dimple pattern on the pointed end, but on the inside there was a cleavage pattern. It was suggested that the cause was the effect of martensite - transition stress in 13%Cr steel.
