| Autor: |
Kozłowska, Aleksandra, Grzegorczyk, Barbara |
| Předmět: |
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| Zdroj: |
Materials & Technologies / Materiali in Tehnologije; Sep/Oct2023, Vol. 57 Issue 5, p36-36, 1p |
| Abstrakt: |
The growing demands concerning the increase of fuel efficiency and passenger safety accelerate the development of Advanced High Strength Steels (AHSS). Currently, the research is focused mainly on the third generation of AHSS, especially medium-Mn steels containing from 3 to 12% of Mn. These steels show the superior combination of high strength and ductility due to the phase transformation of retained austenite into martensite during plastic deformation, which is called strain-induced martensitic transformation (SIMT). Quenching and Partitioning (Q&P) processing is the promising strategy of increasing the strength-ductility product of medium-Mn steels. The Q&P heat treatment consists of austenitization followed by quenching to the temperature between Ms and Mf to produce some fraction of martensite and then a heating step to a higher temperature is applied for C partitioning from the supersaturated martensitic laths into the austenite. Therefore, the Ms temperature of the C-enriched austenite is lower and some fraction of this phase can be stabilized to the room temperature constituting the retained austenite (RA). The aim of this study was to determine the effect of time-temperature parameters of quenching and partitioning heat treatment on the microstructure evolution of 0.17C-4.2Mn-1Al-0.9Si-0.05Nb steel. The heat treatment cycles were performed by means of dilatometry. The obtained microstructures were characterized by scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD) techniques. The quantitative analysis of the fraction of retained austenite after the heat treatment was carried out via X-ray diffraction (XRD). The obtained microstructures are composed of primary martensite formed during quenching, lath-type retained austenite and some fraction of secondary martensite formed during the final cooling. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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