@inproceedings{2b0bba971c6742f68cccf9264ed3dae2,
title = "The effect of niobium on the microstructure and phase transformation kinetics in low-carbon medium manganese steels",
abstract = "Medium-Mn steels are a promising candidate to fulfil the requirements of the 3rd generation of AHSS (Advanced High Strength Steels) which combine high strength with high ductiliy. A new approach is to add micro alloying elements, like niobium, to affect microstructural development. Using a quenching dilatometer, the kinetics of the phase transformations from austenite to its transformation-products at different cooling rates (100 K/s to 0.03 K/s) were investigated for two low carbon medium-manganese steels with different contents of niobium. With the results of optical microscopy (OM), quantitative metallography and scanning electron microscopy (SEM) continuous-cooling-transformation (CCT) diagrams were developed. Furthermore the influence of niobium on the microstructure after intercritical annealing was investigated. The amount of retained austenite (RA) was determined by X-ray diffractometry (XRD). Different etching-methods (Nital, Klemm-I) were applied to reveal different microstructural aspects. Besides considerable grain-refinement effects with increased niobium content, the phase-transformations were accelerated in the CCT-diagrams. The microstructure varies from 100% martensite to higher amounts of bainite, but also ferrite at lower cooling rates. Intercritical annealing results in different amounts of retained austenite.",
keywords = "Dilatometry, Medium-Mn steels, Metallography, Niobium, Retained austenite, X-ray diffraction",
author = "P. Pei{\ss}l and R. Schneider and M. Rahofer and L. Samek and E. Arenholz",
year = "2015",
doi = "10.3139/105.110273",
language = "English",
series = "European Conference on Heat Treatment 2015 and 22nd IFHTSE Congress - Heat Treatment and Surface Engineering from Tradition to Innovation",
publisher = "Associazione Italiana di Metallurgia",
booktitle = "European Conference on Heat Treatment 2015 and 22nd IFHTSE Congress - Heat Treatment and Surface Engineering from Tradition to Innovation",
address = "Italy",
note = "European Conference on Heat Treatment 2015 and 22nd Heat Treatment and Surface Engineering from Tradition to Innovation Congress, IFHTSE 2015 ; Conference date: 20-05-2015 Through 22-05-2015",
}