Effect of Nano‐TiC Ceramic Particles on Microstructures and Properties of High‐Cr Steel under Different Heat‐Treatment Conditions

Abstract

Herein, to improve the service life of die steels, many methods are used to improve their properties. However, some properties may be weakened after different heat treatments. In this study, a novel method of nanoparticle treatment is used to improve the service performance of high‐Cr steel (HCS), and the effect of nano‐TiC ceramic particles on its microstructures and properties under different heat‐treatment conditions is investigated. After forging and isothermal spheroidization, the nano‐TiC ceramic particles treatment HCS has a mixed grain with equiaxed grain and striated grain. Under different heat‐treatment conditions, the nano‐TiC reinforced HCS has refined martensite laths, carbides, and a higher content of retained austenite. In contrast, the nano‐TiC ceramic‐particles‐reinforced HCS that have higher strength and strain, the yield strength (σ 0.2), tensile strength (σ b), fracture strain, product of strength and strain, and impact toughness of HCS‐51 with nano‐TiC (HCSN‐51) are 1349 MPa (1531 MPa), 1662 MPa (1770 MPa), 9.4% (12.1%), 12 405 MPa% (18 766 MPa%), and 266 J cm−2 (445 J cm−2), which is 13.5%, 6.5%, 28.7%, 51.3%, and 67.3% higher, respectively. The primary strengthening mechanisms included fine‐grain strengthening and precipitation strengthening. The main toughness mechanism was fine‐grain and transformation‐induced plasticity.