Effect of W and Mo contents on the microstructural evolution and properties in the 9% Cr martensitic rotor steel during long-term aging at 630 °C

• DOI: 10.1016/j.jmrt.2024.07.069
• Publication Date: 2024-07-15T19:57:33Z
• Authors: Jiajia Qiu; Xikou He; Zhengdong Liu; Zhengxin Tang; Xitao Wang; Jinshan He
• Keywords: Laves phase; Yield strength; Mining engineering. Metallurgy; W and Mo elements; M23C6 carbides; TN1-997; 02 engineering and technology; 0210 nano-technology; 9% Cr martensitic rotor steel

The evolution of tensile properties and microstructure in three 9% Cr martensitic rotor steel with varying contents W Mo elements is investigated after aging at 630 °C for different durations, a primary focus on the characteristics martensite laths blocks, grain boundaries, dislocations, precipitates. results indicate that presence not only influences precipitation coarsening behavior Laves phases but also M23C6 carbides, which differs from conventional beliefs. elevated content reduced leads to reduction equilibrium concentration, promoting enhanced atoms increases nucleation sites carbides. During treatment, carbides 2.0W0.5Mo exhibits highest lowest rate. strength primarily through dislocation strengthening boundary strengthening. fine effectively immobilizes dislocations interfaces, resulting exceptional stability minimal yield strength.