Simultaneously increasing the strength and ductility of hot work die steels is of significant interest for broad applications. The in-situ development of a nano-phase in steels is a promising method for achieving this objective. However, little success has been reported so far. In this study, trace amounts of TiC nanoparticles were successfully introduced into a high-Cr hot work die steel (HHD) through an innovative method using a nano-TiC/Al master alloy. Upon adding 0.02 wt% nano-TiC, an incompletely recrystallized ferrite phase was observed in the HHD containing nano-TiC. Moreover, more globular pearlite was distributed at the ferrite grain boundaries in the HHD with nano-TiC than in the unmodified HHD. The added nano-TiC provided nucleation sites for γ-Fe dendrites and prevented γ-Fe growth during solidification and an austenitizing heat treatment. Furthermore, it noticeably increased the precipitation of more uniform nanoscale chromium carbides and significantly refined the carbides in the HHD during quenching and tempering. Finally, adding nano-TiC simultaneously enhanced the strength and toughness of the HHD. After quenching at 1353 K and tempering at 833 K, the yield strength, tensile strength, tensile strain, and impact toughness of the HHD with nano-TiC were 1330 MPa, 1620 MPa, 14.4 % and 460 J/cm², respectively, which are all higher than those of the HHD without nano-TiC.

同时提高热作模具钢的强度和延展性对于广泛的应用具有重要意义。钢中纳米相的原位开发是实现这一目标的有前途的方法。然而，到目前为止，几乎没有成功的报道。在这项研究中，通过使用纳米 TiC/Al 中间合金的创新方法，将痕量 TiC 纳米颗粒成功引入高铬热作模具钢 (HHD)。添加 0.02 wt% 纳米 TiC 后，在含有纳米 TiC 的 HHD 中观察到未完全再结晶的铁素体相。此外，与未改性的 HHD 相比，具有纳米 TiC 的 HHD 中铁素体晶界处分布的球状珠光体更多。添加的纳米 TiC 为 γ-Fe 枝晶提供了形核位点，并在凝固和奥氏体化热处理过程中阻止了 γ-Fe 的生长。此外，它显着增加了更均匀的纳米级碳化铬的沉淀，并在淬火和回火过程中显着细化了 HHD 中的碳化物。最后，添加纳米 TiC 同时增强了 HHD 的强度和韧性。在1353 K淬火和833 K回火后，纳米TiC的HHD的屈服强度、拉伸强度、拉伸应变和冲击韧性分别为1330 MPa、1620 MPa、14.4 %和460 J/cm 添加纳米TiC同时增强了HHD的强度和韧性。在1353 K淬火和833 K回火后，纳米TiC的HHD的屈服强度、拉伸强度、拉伸应变和冲击韧性分别为1330 MPa、1620 MPa、14.4 %和460 J/cm 添加纳米TiC同时增强了HHD的强度和韧性。在1353 K淬火和833 K回火后，纳米TiC的HHD的屈服强度、拉伸强度、拉伸应变和冲击韧性分别为1330 MPa、1620 MPa、14.4 %和460 J/cm²，分别高于没有纳米TiC的HHD。