Effect of Solid Solution Process on Dissolving Behavior of Precipitates in FB2 Steel

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The dissolution behaviors of the precipitates in FB2 steel after solid solution treatment at 900, 1000, and 1100 °C for 8 h and at 1100 °C for 2, 5, and 10 h are studied by optical microscopy, scanning electron microscopy, X‐ray diffraction, and electrolytic extraction experiments. In the experimental results, it is shown that with the increase of solid solution temperature, the precipitates dissolve obviously, and the martensite lath bundle size and grain size increase. After solid solution treatment at 1000 °C, M23C6 dissolves completely. After solid solution treatment at 1100 °C, BN is generated. With the extension of solid solution time, the precipitates dissolve significantly, the grain size increases, and the number density and volume fraction decrease. From the perspective of microstructure, precipitates evolution, and energy saving, the best solid solution process for FB2 steel is 1100 °C for 8 h.