The effects of vanadium content on the microstructural and mechanical properties of a newly developed hot-work die steel (MPS700V) at room and elevated temperatures have been investigated in this paper. It shows that the ultimate tensile strength (UTS) of MPS700V at room temperat
...
The effects of vanadium content on the microstructural and mechanical properties of a newly developed hot-work die steel (MPS700V) at room and elevated temperatures have been investigated in this paper. It shows that the ultimate tensile strength (UTS) of MPS700V at room temperature and 700 °C are both strongly dependent on the V content. With the increase of V content from 0 to 1.2% V, The UTS at room temperature increases from 1127 MPa to 1442 MPa, and the UTS at 700 °C increases from 400 MPa to 550 MPa. The transmission electron microscope (TEM) shows that the addition of V is beneficial to increase the nucleation rate and volume fraction of MC nano-carbides during the tempering process, and the size of the MC nano-carbides decreases with the increase of V content. The addition of V also increases the thermal stability of MC nano-carbides at 700 °C, which can be related to the reducing the interface mismatch between MC and matrix. Furthermore, a transformation from Orowan bypass strengthening mechanism to shearing strengthening mechanism caused by the V addition is proposed based on the theoretical analysis and TEM observation.@en