Journal article
Kinetics modeling of delta-ferrite formation and retainment during casting of supermartensitic stainless steel
Centre for oil and gas – DTU, Technical University of Denmark1
Department of Mechanical Engineering, Technical University of Denmark2
Manufacturing Engineering, Department of Mechanical Engineering, Technical University of Denmark3
Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark4
The kinetics model for multi-component diffusion DICTRA was applied to analyze the formation and retainment of δ-ferrite during solidification and cooling of GX4-CrNiMo-16-5-1 cast supermartensitic stainless steel. The obtained results were compared with results from the Schaeffler diagram, equilibrium calculations and the Scheil model in Thermo-Calc, and validated by using microscopy and energy dispersive X-ray spectroscopy for chemical analysis on a cast ingot.
The kinetics model showed that micro-segregation from solidification homogenizes within 2–3 s (70 °C) of cooling, and that retained δ-ferrite originates from the incomplete transformation to austenite. The kinetics model predicted the measured amount of δ-ferrite and the partitioning of Cr and Ni reasonably well.
Further, it showed that slower cooling for the investigated alloy leads to less retained δ-ferrite, which is in excellent agreement with experimental results.
| Language: | English |
|---|---|
| Year: | 2017 |
| Pages: | 138-145 |
| ISSN: | 18734197 and 02641275 |
| Types: | Journal article |
| DOI: | 10.1016/j.matdes.2017.01.026 |
| ORCIDs: | Nießen, Frank , Tiedje, Niels Skat and Hald, John |
