Seven samples of austenitic stainless steel strip about 1.5mm thick were produced by the strip casting process. The Creq/Nieq ratio of the stainless steel strips was varied from about 1.23 to 1.95. The solidification structures and the corresponding tensile properties of the as-cast strips were studied. The experimental results show that the solidification mode of austenitic stainless steel strips is dependent on the Creq/Nieq ratio. When the Creq/Nieq ratio is less than 1.48, primary austenite forms during solidification and the strips consist of cellular austenite. However, when the Creq/Nieq ratio is greater than 1.48, primary δ-ferrite forms initially and transforms to an austenite phase through peritectic reaction. As a result, the solidification structures contain about 4-10 vol% δ-ferrite among the austenitic dendrites. The content of δ-ferrite increases with an increase in the Creq/Nieq ratio of the strips. According to the tensile tests, the flow stress at 0.2% elongation and the UTS vary independently of the Creq/Nieq ratio, with the elongation tending to decrease for those strips with a Creq/Nieq ratio less than 1.48 or greater than 1.81. It appears that this is related to micro-shrinkage porosity in the austenitic structures and to interfacial tears in the γ/δ dendritic structures.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys