激光诱导不同表面状态TP347H钢的等离子体光谱特性

The LIBS Plasma Characteristics of Different Surface State of TP347H Steel

选用火力发电厂锅炉受热面现场服役TP347H作为研究对象,研究不同样品表面状态(打磨和未磨)的等离子体光谱特性.实验结果表明:随着激光击打次数的增加,两种不同状态条件下获得的光谱数据的变化趋势存在较大差异;对于未磨样品,在击打的过程中可连续探测到很强的Ca的特征谱线;而对于打磨样品,只在刚开始的几个激光脉冲中存在Ca的特征谱线.对TP347H本身含有的元素Fe、Mn来说,未磨状态时,随着激光击打次数的增加,绝对光谱强度先迅速增加,然后又慢慢减小;打磨后的样品,随着激光击打次数的增加,绝对光谱强度先迅速增加,之后在一定范围内趋于稳定.未磨样品表面存在积灰黏结以及氧化层,会在一定程度上增强探测的光谱强度、等离子体温度及电子密度,而打磨之后有助于获取更加稳定的光谱数据.

Choosing the TP347H steel which is used for the boiler heating surface in the thermal power plants as a research object, the characteristic of plasma spectral of the samples with different surface states（the unground and the ground） was analyzed. The experiment results show that, the change trends of the acquired spectral data of the two surface states are great difference with the increase of the laser hitting times. For the unground samples, the characteristic spectral line of Ca can clearly be detected in the whole experiment process. For the ground samples, the characteristic spectral line of Ca only exists in the beginning. For the unground TP347H samples containing of the elements of Fe and Mn, the absolute spectral intensity increases rapidly then reduces with the increase of the laser hitting times. For the ground TP347H samples, the absolute spectral intensity increases rapidly firstly then keeps relatively stable within a certain range with the increase of the laser hitting times. The unground samples exists fouling and slagging on the surface, which can enhance the spectral intensity, plasma temperature and electron density in a certain extent. But the spectral data stability of ground partis is better than that of the ground samples.