Microstructure and impact toughness evolution in high-strength anchor chain steel: A Jominy test-based investigation
Ensuring the impact toughness of anchor chains remains challenging due to inhomogeneities in microstructure and mechanical properties induced by variations in cooling rates during quenching. In this research, the evolution of microstructure and impact toughness at different distances from the quench...
Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-06-01
|
| Series: | Materials & Design |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127525005337 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Ensuring the impact toughness of anchor chains remains challenging due to inhomogeneities in microstructure and mechanical properties induced by variations in cooling rates during quenching. In this research, the evolution of microstructure and impact toughness at different distances from the quenched end (dqe) of the Jominy test for a high-strength anchor chain steel were analysed though instrumented Charpy impact tests, microstructure characterization, phase transformation kinetics, and crystallographic analysis. Our results reveal that with the increase of dqe, the transformed microstructure gradually transits from full martensite (1.5 mm, dqe hereafter the same) to martensite dominant (9 mm) and bainite dominant (13–40 mm), accompanied by a monotonic decrease in Vickers hardness. The impact absorbed energy at 0℃ increases from 172.83 J (1.5 mm) to 215.24 J (9 mm) despite the reduced density of high angle grain boundary, due to the higher ductility at dqe of 9 mm enhancing both the crack initiation and propagation energy. Then the impact absorbed energy continuously decreases from 215.24 J (9 mm) to 124.97 J (40 mm), attributed to the higher ductile–brittle transition temperature for coarser microstructure at larger dqe, which increases the proportion of brittle fracture surface. The coarser microstructure at larger dqe can be explained by the severe variant selection during phase transformation. |
|---|---|
| ISSN: | 0264-1275 |