【摘要】 表面硬度是表征钢铁特性的重要参量之一,表面硬度的检测可以把关工业生产质量。在自行搭建的LIBS实验平台获取激光诱导击穿光谱(LIBS),控制激光能量为30 mJ,比较了基体元素FeⅠ404.58 nm和合金元素MnⅠ403.07 nm的光谱强度与6个不同D2钢硬度的样品(经过不同热处理得到不同硬度)之间的相关性,发现合金元素Mn的光谱强度与硬度的决定系数(0.934)高于基体元素Fe的决定系数(0.916)。采用LIBS中Fe的离子与原子光谱强度比及激光诱导等离子体温度表征不同热处理的D2钢硬度,选择FeⅡ275.57 nm和FeⅠ276.75 nm的两条特征谱线作为分析谱线,建立了表面硬度与光谱信号之间的关系(决定系数为0.964);激光诱导等离子体温度作为等离子体重要参数与硬度建立了很强的正相关性(决定系数为0.977)。D2钢表面硬度可以通过不同热处理改变组织进而改变硬度,同时加入合金元素(例如通过加入Mn可以细化晶粒改善钢的硬度)也可以改变硬度。实验同时建立了不同含量Mn的D2钢硬度与光谱强度(MnⅠ403.07 nm)之间的相关性, D2钢的硬度不随Mn含量的增加而单调增加,而光谱强度却随硬度有一致性变化。实验结果表明利用基体元素Fe、合金元素Mn, Fe元素离子与原子光谱强度比和等离子体温度可以与不同硬度D2钢建立正比关系,光谱强度有效地表征了不同热处理得到的D2钢硬度;不同Mn含量得到的D2钢硬度有效地验证了光谱强度表征硬度的可行性。因此, LIBS光谱技术表征钢铁材料硬度特性得到了实验验证,展现了工业现场控制中的应用前景。更多还原

【Abstract】 Surface hardness is a critical parameter to characterize steel properties. Its monitoring plays a key role in Industry. In the present paper, the spectral line intensities between element Fe Ⅰ 404.58 nm and Mn Ⅰ 403.07 was compared with 6 different hardness samples by using laser induced breakdown spectroscopy(LIBS) in self-built device in which laser energy was 30 mJ. The coefficient of determination for Mn(0.964) was better than Fe(0.916). The ratio of the Ferrum ionic to atomic spectral lines intensities(Fe Ⅱ/Fe Ⅰ)and laser induced plasma temperature have been characterized by the hardness of D2 steel for different heat treatments. The relationship has been obtained between surface hardness and the ratio of the Ferrum ionic to atomic spectral lines intensities(the coefficient of determination was 0.964). Fe Ⅱ 275.57 nm and Fe Ⅰ 276.75 nm were selected as analytical spectral lines. The relationship between surface hardness and laser induced plasma temperature has been established too(the coefficient of determination was 0.977). The hardness of D2 steel could be changed by different heat treatments, as well as the addition of alloying elements. For example, adding manganese into D2 steel could improve the hardness by refining grains. The correlation between Rockwell hardness of D2 steel for different content of manganese and Spectral signal intensity(Mn Ⅰ 403.07 nm) was established. The hardness of D2 steel does not increase monotonically with the increase of Mn content, but the spectral intensity changes consistently with the hardness. The experimental results validated that the element Fe and Mn, the Fe Ⅱ/Fe Ⅰ spectral lines intensities and laser induced plasma temperature had a good linear correlation with the hardness of D2 steel. And the different hardness obtained by different addition of Mn in D2 steel had a good linear correlation with a spectral intensity which verified the relation between hardness and spectral intensity. The determination of the surface harness via LIBS shows the feasibility of using LIBS as a reliable method for in situ industrial application for production control.更多还原