20SiMn低合金钢在不同砂粒粒径的多相流中的损伤行为

DAMAGE BEHAVIOR OF 20SiMn LOW ALLOY STEEL IN SLURRY WITH DIFFERENT PARTICLE SIZES

利用旋转圆盘仪对20SiMn低合金钢在6种砂粒粒径下的多相流损伤进行了研究。结果表明,失重随粒径变化有明显的转折点;大粒径下空蚀的存在对失重有显著的影响,而小粒径影响很小,小粒径和大粒径下材料的损伤形貌差别很大,分析表明,粒径的变化引起了材料损伤机制的变化,小粒径时为选择性冲蚀破坏机制,大粒径时为犁削破坏机制。

The damage mechanism of 20SiMn low alloy steel in slurry with different particle sizes was studied using a rotating disk system. The results indicate that the curve of mass loss vs particle size exhibits a clear transition point beyond which the mass loss increases sharply. The SEM images of specimens suffering erosion and cavitation of big particles are obviously different from those of small particles. The damage mechanisms under conditions of small particle and big particle are selective erosion of relative soft ferrite phase and ploughing, respectively. Cavitation adds little effect to slurry erosion under condition of small particles, and obvious effect under condition of big particles.