Homogeneity analysis of Y-bearing 12Cr ferritic/martensitic steel fabricated by vacuum induction melting and casting

Advanced oxide metallurgy technique was adopted to produce 100-kg Y-bearing 12Cr ferritic/martensitic steel via vacuum induction melting and casting route. Subsequently, nine specimens at top, middle and bottom regions of the sheet were characterized to evaluate the homogeneity of chemical composition, microstructure and mechanical properties. The small vibration of hardness (200-220 HBW), ultimate tensile strength (672-678 MPa), yield strength (468-480 MPa), total elongation (26.2%-30.5%) and Charpy energy at room temperature (98-133 J) and at - 40 degrees C (12-40 J) demonstrated that mechanical properties' homogeneity of Y-bearing steel was acceptable although slight Y segregation and inhomogeneous microstructure occurred at the bottom. Furthermore, the effect of Y content on microstructure characteristics and mechanical properties was explained and the comparison of failure mechanism for the dual-phase steel between tensile test (i.e., quasi-static loading) and Charpy test (i.e., dynamic loading) was discussed in detail.