High-speed gas-solid two-phase flow erosion of 1Cr9Mo alloy

A self-made gas-solid erosion testing apparatus driven by shock wave was used to investigate the wear properties of 1Cr9Mo steel commonly used as manufacturing materials in the coal chemical industry, and SiO₂, Al₂O₃ and SiC particles were chosen as erosive particles. Combined with the surface morphology analysis of eroded specimens, high-speed erosion wear characteristics were studied under different conditions involving impact velocity, impact angle, particle hardness, particle size, and specimen temperature. The results show that when the temperature is 20 22 and 400 22, the erosion rate of 1Cr9Mo steel reaches its maximum value within an impact angle range of 15° to 25°, and the wear properties are characterized as ductile metal. At low impact angles the cutting of particles is the main mechanism; but at large impact angles the erosion mechanism is the exfoliation of platelets around the pits from the material surface, which is produced by the vertical impact of particles to the material surface. When the velocity exponent of 1Cr9Mo steel ranges from 2.3 to 3.2, the erosion rate is much dependent on particle hardness. Under the same erosion conditions, the erosion rate caused by Al₂O₃ and SiC particles is an order of magnitude higher than that caused by SiO₂ particles for they have higher hardness values. With the increase of particle size, the erosion rate increases first and then falls. The erosion rate caused by SiO₂ particles at 400 ℃ increases significantly, and the maximum erosion rate is 3 times as large as that at 20 22.