Effect of Cold Rolling on Texture and Microstructure Development in Annealed Incoloy 800 Fabricated Using Selective Laser Melting.

Incoloy 800 is a Fe-based super alloy used primarily in high-temperature applications like boilerplates due to its ability to maintain its austenitic phase. Samples of 100 × 20 × 5 mm were manufactured in vertical orientation using selective laser melting (SLM) and were annealed at 980 °C for 15 min. Annealed samples were cold rolled at room temperature, in multiple passes to 20, 40, 60 and 80% reduction in thickness, perpendicular to the building direction. The aim of this study is to understand the strain hardening effect upon rolling and also to know the effect of cold rolling on texture, microstructure and hardness after rolling the annealed alloy. Microstructural features were observed under optical microscope and scanning electron microscope while the texture measurement was done using X-ray goniometer. Typical fish scale morphology was observed in the transverse plane of as-built condition, which was diminished in annealed samples. SEM study shows fine grains along with traces of lamellar cell morphology. Hardness increased with an increase in percentage reduction. Austenite (γ) phase was detected as the only phase in XRD analysis. The bulk texture of annealed sample revealed strong copper texture until 40% rolling, and thereafter, it reduced. Goss texture component showed a similar trend, while brass texture increased up to 60% rolling condition and thereafter diminished. [ABSTRACT FROM AUTHOR]