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Determination of chemical composition and hardness of railway steels in air by means of LIBSтезисы доклада
- Авторы: Sergey Zaytsev, Timur Labutin, Andrey Popov, Andrey Kuznetsov, Vadim Dyundin, Radmir Garaev, Nikita Zorov
- Сборник: The 8th International Conference on Laser-Induced Breakdown Spectroscopy
- Тезисы
- Год издания: 2014
- Место издания: Tsinghua University Beijing
- Первая страница: P-115
- Последняя страница: P-115
- Аннотация: The world production of railway rails and its quality requirements increase every year. It is caused by the construction of new railways as well as repair and replacement by new ones, providing higher wear resistance and durability. The quality of rails is primarily determined by elemental composition of steels – both of main and alloying components contents. LIBS is highly suitable for direct steel analysis. Moreover, LIBS can be helpful in online diagnostics of the physical state of railways. While the chemical composition of rails actually does not change during exploitation, mechanical properties can be varied significantly, especially on a rolling surface. It is known, the physical properties influence parameters of laser-induced plasma. Thus, rapid analysis by LIBS gives an advantage during the production of steel and rails and the field inspection of railroad track. The present work was aimed at analysis of railway steels in air only to simplify the technique and instrumentation. We used Nd:YAG laser for ablation (532 nm, 60 mJ/pulse, fluence was ~10 GW/cm2) and Cherny Turner spectrometer equipped with ICCD camera for emission registration. The range of analyzed elements included manganese, titanium, vanadium, aluminum, silicon and carbon. Analytical lines were Mn I 404.14 nm with internal standard of iron line Fe I 395.67 nm, Ti II 457.20 nm, V I 437.92 nm, Al I 394.40 nm, Si I 212.41 nm and C I 833.51 nm. For determination of carbon in steels the second laser was used for collinear double pulse LIBS. The small interpulse delay time (1 μs) provided the best conditions for carbon emission enhancement. Principal Component Regression was implemented to eliminate strong interference of iron lines. We achieved the sufficient SNR for analysis within the required ranges of concentrations of the elements in the optimal experimental conditions and provided an analysis of the sample of real rail, which allowed identifying of steel grade. Finally, we found the correlation between hardness of several rail samples with the different quenching (HB varied in the range 300 - 650) and electron density of laser plasma, estimating by width of Hα 656.3 nm line. The density was decreased with the increasing of hardness.
- Добавил в систему: Попов Андрей Михайлович