EFFECT OF POST-PROCESSING ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ULTRA-LOW CARBON STEEL FABRICATED BY SELECTIVE LASER MELTING

摘要

In this study, the effects of heat treatments and hot-isotactic pressing (HIP) on the microstructure and mechanical properties of ultra-low carbon steel produced using selective laser melting (SLM) were investigated. Powder and prototypes characterizations including XRD phase analysis, microstructural observations, and hardness were performed. It was found that heat treatments at 1000 °C and HIP process improved inter-particle bonding very slightly. Significant increases in the grain size were observed for the annealed specimens at 600°C and above as well as after HIP due to recrystallization and further grain growth, which coincide with the drop in hardness.