Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7971607 | Materials Science and Engineering: A | 2018 | 10 Pages |
Abstract
A high strength steel with Nb-V-Ti addition was heat treated by a series of isothermal bainite holding (IBH) processes and quenching and partitioning (Q&P) processes with different intercritical annealing temperatures. The microstructure observation showed that some martensite was formed during quenching in IBH condition with annealing temperature above 850â¯Â°C, mainly ascribed to heterogeneous carbon content distribution in parent austenite with relatively large size. Meanwhile, film-like RA in martensite, relatively coarser lath-like RA in bainite and blocky RA located in grain boundaries or phase boundaries were observed in both IBH and Q&P treatments. Moreover, Q&P process was proved to be more beneficial to retain austenite than IBH process, while the ability of austenite retention was similar in IBH conditions. An excellent combination of strength and ductility was obtained in Q&P process annealed at 880â¯Â°C with tensile strength of 1126â¯MPa and total elongation of ~â¯18%, attributing to TRIP effect mainly occurred in the latter part of strain and fine microstructure with homogeneous distribution.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Fei Peng, Yunbo Xu, Xingli Gu, Yuan Wang, Jianping Li, Hua Zhan,