Thermal degradation of stainless steel
Metallers are adversely affected by high temperatures. Oxides on the surface, thermal fatigue and creep are some of the negative effects that high temperatures bring.
Alloys such as stainless steels contain a complex chemical composition to avoid these negative effects. If this balance of alloying elements is upset, the negative effects can be amplified.
The project investigated how heat treatments affected a number of different castable stainless steels with different additions of alloying elements. Among other things, the project was able to show that an addition of titanium improved the adhesion of the oxide layer to the surface, while a higher silicon content led to a poorer adhesion. Silicon also contributed to a greater proportion of sigma phase, a harmful and brittle phase, being formed in the material.
In the project, SEM and EDS were used to verify oxide thicknesses and its composition. EDS mapping was used to understand how segregation of alloying elements could lead to new phases.
The project was financed by Hjalmar Lundbohm's research center (HLRC) and LKAB.

Updated:
Page author: Contact us