Enhancing strength-toughness synergy of Cu-containing marine steel via regulating precipitation behavior
The multi-microalloying treatment was applied to Cu-bearing marine steel to regulate its precipitation behavior with aim of reinforcing the balance between strength and toughness. The results indicated that the incorporation of Ti created cuboidal Ti(C,N) particles alongside a quantity of finer sphe...
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| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-05-01
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| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425013134 |
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| Summary: | The multi-microalloying treatment was applied to Cu-bearing marine steel to regulate its precipitation behavior with aim of reinforcing the balance between strength and toughness. The results indicated that the incorporation of Ti created cuboidal Ti(C,N) particles alongside a quantity of finer spherical (Ti,V)C precipitates. The formation of rich-Ti carbonitride refined the prior austenite grains (PAGs) and facilitated the nucleation of Cu-rich particles, leading to an increase in the content while inhibiting their coarsening and structural transformation. The strengthening contributions from grain boundary and precipitation enhanced by co-precipitation of Cu and MC carbonitrides were sufficient to compensate for the loss of dislocation strengthening and solid solution strengthening caused by the consumption of C content in the matrix due to the formation of MC carbides. Consequently, V–Ti steel exhibited better tensile properties and excellent tempering stability, with its yield strength (YS) exceeding that of V steel by 78 MPa after tempering at 620 °C. Simultaneously, the presence of MC and M3C carbides diminished the precipitation kinetics of M23C6 carbides, mitigating the adverse effects on interfacial bonding strength due to the decrease in content. Combining the softening effect resulting from the reduced C concentration in the matrix and the preventing effect of high angle grain boundaries (HAGBs) increased by grain refinement on cracks propagation, the transverse cryogenic impact toughness of V–Ti steel was significantly improved, with an impact energy maintained at ∼50 J after tempering at 460–580 °C, and even increased to 75 J at 620 °C because of further recovery/recrystallization. |
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| ISSN: | 2238-7854 |