Article ID Journal Published Year Pages File Type
7972686 Materials Science and Engineering: A 2018 12 Pages PDF
Abstract
A low carbon steel microalloyed with Nb-V-Ti were heat treated by means of two-step quenching and partitioning (Q&P) process after partial austenitization. Combined use of SEM equipped with EBSD, XRD and TEM showed that the microstructure was composed of intercritical polygonal ferrite, tempered lath martensite, secondary twin martensite and carbon-enriched retained austenite, as well as microalloyed carbides (mainly VC) precipitated inside ferrite and martensite. When increasing partitioning time from 0 s to 3600 s, the volume fraction of retained austenite increased up to 6.5% with mean carbon content in austenite keeping a constant level. The retained austenite kept K-S orientation relationship with adjacent tempered lath martensite and neighboring secondary twin martensite in different martensite packet. As partitioning time increased up to 3600 s, the initial lath martensite tempered gradually to ferrite without any cementite formation.
Related Topics
Physical Sciences and Engineering Materials Science Materials Science (General)
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