A nanoindentation study on the micromechanical characteristics of API X100 pipeline steel

초록

The hardness characteristics of constituent micro-phases (ferrite and bainite) in a dual-phase API X100 pipeline steel were analyzed by nanoindentation experiments. The measured nano-hardness of the bainite phase is from 3.8 GPa to 4.9 GPa, which is much higher than that of the ferrite phase, which ranged from 1.75 GPa to 2.3 GPa. With the hardness and volume fraction of each micro-phase, attempts were made to predict the overall hardness by applying a simple rule-of-mixture. A comparison between the predicted overall hardness value and the experimentally measured value revealed that the rule-of-mixture can be successfully applied for prediction purposes. The results are discussed in terms of the grain boundary strengthening effect and the indentation size effect.

키워드