The addition of rare earths to steel can alter the composition and morphology of endogenous inclusions and play a role in the purification of steel.Therefore,it is widely used in many low alloy steels.However,the mechanism by which different states of rare earth elements affect the properties of steel remains unclear.The presence of rare earth elements in steel leads to a complex morphology due to their strong affinity with non-metallic elements such as oxygen and sulfur.This complexity poses challenges in the classification and quantitative characterization of rare earth inclusions in steel.A combination of continuous acquisition of multi-field images for scanning electron microscopy(SEM),automatic identification of characteristic particles and high-performance energy dispersive spectrometer have been used to achieve the characterization of the location,composition,size and amount of rare earth inclusions in oil well pipe steel over a wide range of dimensions.The impact of varying Ce contents on the types,quantities and sizes of rare earth inclusions in steel has been studied.When the Ce content is low,more Ce-containing inclusions encapsulate or embed Al2O3 and MnS.As the Ce content increases,single Ce inclusions gradually form.These inclusions are spherical or long ellipsoidal with particle sizes ranging mainly between 1 and 4 μm.These particles are dominated by Ce-O,Ce-O-S,and Ce-S.Phosphides of Ce are formed at higher Ce content.The P-containing rare earth inclusions exhibit banding in the test area.
关键词
稀土油井管用钢/Ce夹杂物/定量统计分布表征/扫描电镜/能谱
Key words
rare earth oil well pipe steel/Ce-containing inclusion/quantitative statistical distribution/scanning electron microscope/energy spectrum
维普
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