Study Of The Laser-Induced Breakdown Spectroscopy Of Boiler Heating Surface Material With Different Mechanical Properties

Power plant boiler heating surfaces, for a long time, are survived in the harshenvironment where is high temperature and high voltage. Obviously, whose material insecurity and reliability have a significant impact on not only safety and economic productionin thermal power plants, but safe and stable operation of grids, as well as the nationaleconomic development.Laser-Induced Breakdown Spectroscopy(LIBS), whose analytical technique is based onthe atomic emission spectrometry, possessing a plenty of advantages such as the simplestructure, slight destruction on the analysis of the object and rapid multi-elementsimultaneous, long-distance and non-contact analysis, moreover, LIBS is able to adapt to avariety of harsh environments, real-time online measurement, even showing immensepotential applications in many fields. Meanwhile, LIBS exist obvious matrix effect, therefore,the traditional quantitative analysis should be reduced the effect in order to improve thereliability of the technical measurement.However, because of the existence of matrix effects, making the laser plasma spectralcharacteristics, to some extent, can reflect the characteristics of the substrate material,consequently, it can be used for material elements of the distribution, structure change andmaterial performance characteristics of qualitative analysis as well as material characteristicsdiagnosis in the industrial site.The essay will introduce the new type of atomic emission spectrometry technology--Laser-induced Breakdown Spectroscopy into the diagnostic field of the thermal heatingsurface material. Through theoretical and experimental studies, it provides evidence in LIBSfailure analysis of rapid diagnosis and application in the heating surface material. Thedissertation expounds the existing research at national and abroad based and grasps theablation process between the laser and the heating surface of the metal material samples andplasma generation mechanism. A experimental system using for analysis the metal materialsof the heating surface has been established. Then, various influencing parameters is analyzedsystematic to optimize the detection system, and all this may build a bridge to the nextresearch. Changes about mechanical properties in the failure process can be characterized bythe hardness indicator. The different hardness of12Cr1MoV samples obtained by heattreatment process are used for analyzing the spectral intensity and plasma characteristics ofdifferent hardness materials, combined with metallographic analysis. Finally, a principalcomponent analysis techniques to distinguish between samples of different hardness classified the initial failure degree of judgment.At last, the full essay is summed up, and the further research work of LIBS applied tothe heating surface material failure analysis will be done in future.