Why Does Nitriding of Grain‐Oriented Silicon Steel Become Slower at Higher Temperature?

The nitriding process plays an essential role in the production of grain‐oriented silicon steel (GOSS) via the acquired‐inhibitor process. It is surprising at first glance to find that the increase of temperature from 840 to 930 °C retards the nitriding of GOSS rather than accelerating it. By both extensive microstructural characterization and thermodynamic calculations, this is attributed to the formation of austenite at high temperature in the...