Quantification of retained austenite by X-ray diffraction and saturation magnetization in a supermartensitic stainless steel

• The phase transformation during secondary tempering temperatures was observed.
• Phases were quantified by X-ray diffraction and DC-saturation magnetization.
• More retained austenite forms with increasing secondary tempering temperature.
• The retained austenite is mainly located at the grain and lath boundaries.

The good performance of supermartensitic stainless steels is strongly dependent on the volume fraction of retained austenite at room temperature. The present work investigates the effect of secondary tempering temperatures on this phase transformation and quantifies the amount of retained austenite by X-ray diffraction and saturation magnetization. The steel samples were tempered for 1 h within a temperature range of 600–800 °C. The microstructure was characterized using scanning electron microscopy and electron backscatter diffraction. Results show that the amount of retained austenite decreased with increasing secondary tempering temperature in both quantification methods.

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