激光诱导击穿光谱法对钢中夹杂物类型的表征

摘要

激光诱导击穿光谱( LIBS)不仅可以对材料整体成分进行分析,还可进行微区及成分分布分析。本实验采用激光诱导击穿光谱对两牌号钢铁样品进行扫描分析,尝试对34CrNiMo6钢中的MnS夹杂物和重轨钢中的Si-Al-Ca-Mg复合夹杂物进行表征。结果表明,34CrNiMo6钢中元素信号的二维强度分布及元素通道合成后,个别位置Mn及S两元素的信号强度同时异常高,可确定试样中存在较多MnS夹杂物；重轨钢中元素的二维强度分布及元素通道合成后,个别位置Si、Ca、Mg及Al元素的信号同时异常高,可确定试样中存在Si-Al-Ca-Mg复合夹杂物。采用扫描电子显微镜/能谱法( SEM/EDS)对上述样品中夹杂物的对比分析结果表明,两种方法对夹杂物类型的判定结果一致。%ScanningElectronMicroscopy/EnergyDispersionSpectrum(SEM/EDS),ElectronProbe Microanalysis ( EPMA ) and Optical Microscopy ( OM ) are the traditional methods for inclusion type identifying at present. The disadvantages such as inconvenient sample preprocessing, low sensitivity and time consuming limited their application. Laser-Induced Breakdown Spectroscopy ( LIBS) is not only performing in bulk analysis field but also in elemental distribution and depth profile information field, so it causes great concern in material science. In this paper, 34CrNiMo6 steel and heavy railway steel samples were analyzed by LIBS in scanning mode to characterize the inclusion type. For 34CrNiMo6 steel, 2D intensity distribution and channel combination revealed the spectra line intensity of Mn and S were abnormal high simultaneously at some region, which indicated there were some MnS inclusion existed in these samples. And for heavy railway steel, 2D distribution and channel combination revealed the spectra line intensity of Si, Ca, Mg and Al were abnormal high simultaneously at some region, showed the existence of Si-Al-Ca-Mg inclusion in these samples. The SEM/EDS analysis result of above-mentioned samples showed agreed well with LIBS.