Effects of Solution Aging on Carbide Morphology and High Temperature Compressive Strength of Cr-Mo-V Alloyed Ductile Iron

Based on the composition design and heat treatment principles of hot work die steel and high-temperature alloys, the horizontal continuous casting technology was employed to prepare Mo, Cr, and V-alloyed ductile iron. The alloy was then subjected to solution-aging heat treatment. The microstructure of the samples was analyzed using optical microscopy（OM） and X-ray diffraction（XRD）, while the mechanical properties were tested using Rockwell hardness and hightemperature compression tests at 500 ℃. The mechanisms by which alloy elements and carbon atoms influenced the strength and hardness of the Mo-Cr-V alloyed ductile iron were explored. The results show that, some primary carbides do not decompose, even with elevated solution temperatures and prolonged solution time. The microstructure obtained under a solution temperature of 1050 ℃ and a solution time of 1 h is most favorable for subsequent aging treatment. At a solution temperature of 1050 ℃, a solution time of 1 h, and an aging temperature of 500 ℃, the Mo-Cr-V alloyed ductile iron achieves the best mechanical properties, with a Rockwell hardness of 55.9 HRC and a high-temperature compressive strength of 2144.6 MPa. Additionally, the friction coefficient of the alloy decreases as the load in the friction and wear tests increases.