Researchers gain a better understanding of the transformation of steel

Heating iron can alter its structure and is one of the methods for making various types of steel with different properties. That process is similar to the formation of frost flowers: one iron crystal structure transforms into another at a nucleus point, and the process expands further from that point. This type of nucleation in materials has the largest impact on their final properties, but is still the least understood in the field of metallurgy. For example, we still know little about how and where exactly this nucleation starts. Researchers at TU Delft have now shed new light on this subject in their publication ‘Preferential Nucleation during Polymorphic Transformations’ in Scientific Reports(Nature) of Wednesday 3 August.

The researchers demonstrated this nucleation process live by heating an iron sample to 1,000 degrees in a specially produced furnace at the European Synchrotron Radiation Facility in Grenoble, and monitoring the transformation process using X-rays. In this way, they were able to identify the places and their properties that were the most likely starting points for the nucleation process of the transition from ferrite to austenite.

Read more.