高铬铸铁在液-固两相流中的冲蚀磨损行为

Erosion Wear Behavior of High Chromium Cast Iron in Fluid-solid Two-phase Flow

研究不同Cr含量的高铬铸铁(Cr12、Cr15、Cr23和Cr28)在液固两相流(浓度为3.5的H2SO4+石英砂)的冲刷腐蚀磨损行为。采用光学显微镜(OM)、扫描电镜(SEM)、X射线衍射(XRD)等手段观察表面形貌特征和分析腐蚀产物的相组成,通过分析单位面积的质量损失研究冲蚀磨损行为。结果表明,基体首先遭受腐蚀,当Cr含量≤15%时,高铬铸铁腐蚀产物中无氧化膜或氧化膜为不致密的Fe_2O_3时,腐蚀和冲刷磨损之间的交互作用使单位面积的质量损失率不断增加。Cr含量≥23%时,高铬铸铁腐蚀产物主要为Fe_2O_3和Cr_2O_3,当Cr_2O_3膜的厚度增加到一定程度后,延缓了冲蚀磨损进程,单位面积的质量损失表现为先增加后又降低。

Erosion wear behavior of high chromium cast iron with different Cr content（Cr12,Cr15,Cr23 and Cr28）was observed in liquid-solid two-phase flow（H2SO4＋quartz sand）.Surface morphologies and the phase constituent of corrosion products were analyzed by means of optical microscope（OM）,scanning electron microscopy（SEM）and X-ray diffraction（XRD）.Erosion wear behavior was investigated by the analysis of weight loss per unit area.The results reveal that the matrix is firstly susceptible to corrosion,and corrosion products have an important influence on erosion wear behavior.When Cr content is lower than 15%,corrosion products have the absence of oxidation film or presence of Fe_2O_3 film,so weight loss per unit area is increased as a result of the interaction of corrosion and erosive wear.With more than 23% high chromium cast iron,the corrosion products are mainly composed of Fe_2O_3 and Cr_2O_3.With thickness of Cr_2O_3 film increased to a certain degree,the erosion wear behavior is delayed,so weight loss per unit area is increased firstly and then decreased.