Ф6.71 m湿式球磨机衬板用75Cr2MoSiMnNi钢的热处理及耐冲蚀磨损性能

Heat treatment and erosion corrosion resistance of 75Cr2MoSiMnNi steel plate for Ф6. 71 m wet ball mill liner

对应用在Ф6. 71 m×9. 12 m湿式球磨机上的Cr-Mo系衬板材料75Cr2MoSiMnNi钢板进行了热处理工艺及冲蚀磨损性能研究。结果表明:经不同温度加热及喷雾冷却后,随着加热温度的升高,材料的硬度增加,冲击性能下降;经880℃×2 h加热及喷雾冷却,并580℃高温回火后,75Cr2MoSiMnNi钢具有最佳的强韧性配合。对热处理后的75Cr2MoSiMnNi钢板进行冲蚀磨损试验研究,结果表明:随着冲蚀角度的增加,75Cr2MoSiMnNi钢的磨损量呈现先增加后减少的趋势,在冲蚀角为60°时,磨损量最大,因此在工程应用中应避免该冲蚀角的出现;在固定冲蚀角的情况下,随着冲刷速度的增加,固-液双相流对材料的作用力急剧增大,腐蚀产物膜脱落,液相在脱落坑的周围形成湍流,促进了腐蚀产物的产生和脱落,因此在保证工程应用正常进行的情况下,应尽量减小冲刷速度。

Heat treatment process and erosion wear behaviour of Cr-Mo liner material 75 Cr2 MoSiMnNi steel plate applied to φ6. 71 m × 9. 12 m wet ball mill were studied. The results show that with the increase of quenching temperature,the hardness of the material increases and the impact property decreases. After austenitized at 880 ℃ for 2 h,and then spray cooled and tempered at 580 ℃,the 75 Cr2 MoSiMnNi steel has the best combination of strength and toughness. The results of erosion wear test show that,with the increase of erosion angle,the wear loss of the 75 Cr2 MoSiMnNi steel increases first and then decreases,and when the erosion angle is 60°,the wear loss is the largest,so such an erosion angle should be avoided in engineering application. Under the condition of fixed erosion angle,with the increase of scouring velocity,the force of solid-liquid two-phase flow on the material increases sharply,the corrosion product film can be shed off. The liquid phase forms turbulence around the shedding pit and promotes the production and exfoliation of corrosion products. Therefore,the scour speed should be minimized under the condition of ensuring the normal engineering application.