Conditions for the Efficient Crushing of the As-Cast Microstructure of 30Cr10Ni Duplex Stainless Steel

The hot-deformation behavior of as-cast 30Cr10Ni duplex stainless steel was investigated with the aim to understand the conditions better that lead to the occurrence of cracking. Because of the increased content of Cr, Ni, and C, the 30Cr10Ni ferrous alloy exhibits a complex microstructure, especially in the as-cast state in which, in addition to the ferrite, austenite, and sigma phases, carbides also are present; this leads to a very complex hot-deformation behavior. Hot-compression tests on specimens with an as-cast initial microstructure in the temperature range 1223 K (950 °C) to1573 K (1300 °C) and strain rates of 0.1 to 5.0 s⁻¹ were carried out. To find the most appropriate sequence of initial hot-deformation steps for the effective crushing of the as-cast microstructure, a special experimental procedure was developed. The results indicate that in the temperature range 1423 K (1150 °C) to 1523 K (1250 °C), the as-cast microstructure exhibits increased workability, whereas below this temperature, the microstructure is prone to cracking. As such, the as-cast microstructure should be crushed in the high-temperature range to avoid the occurrence of cracking.