In-situ neutron diffraction study of wrought and selective laser melted maraging stainless steels

摘要: Abstract Bulk phase transformations and dislocation density were monitored in a maraging stainless steel on bulk level using in-situ neutron diffraction up to 1340 °C, i.e. 30 °C below the melting temperature. Three materials with different initial microstructure and/or composition studied: wrought, as-built SLM-ed (selective laser melted) re-austenitized SLM-ed. In contrast wrought martensitic steel, was essentially ferritic. However, recovered usual microstructure. A δ-ferritic domain above 1200 °C confirmed for all studied. amount of δ-ferrite at point strongly depends upon composition. Additionally, it shown that (ferritic or martensitic) has little no influence re-austenization. Dislocation densities estimated from peak broadening. The ferritic SLM material contains high (~4 × 1014 m−2), which is however far less than (~5 × 1015 m−2). Dislocations start annihilate 550 °C / 600 °C studied, but measurable ~1013 m−2 still observed 950 °C 1000 °C.