Bulk analysis of steel samples with surface scale layers by enhanced laser ablation and LIBS analysis of C, P, S, Al, Cr, Cu, Mn and Mo

Abstract

To control the steel composition during production in steel works, samples are taken from the melt. After solidification, the samples exhibit scale layers of about 0.1-1 mm thickness. At present, for analysis of the bulk composition, e.g. by optical emission spectrometry using arc/spark excitation, the scale layer is removed by grinding or milling and afterwards the prepared sample is measured. In this study we use multi-pulse bursts of a Nd:YAG laser at 1064 nm wavelength to ablate the scale layer of low-alloy steel samples locally in a first step, and the bulk material is analysed in a second step by laser-induced breakdown spectrometry (LIBS). With a LIBS set-up including a Paschen-Runge spectrometer, detection limits below 10 µg g(exp -1) are determined for elements such as C, P, S, Al, Cr, Cu, Mn and Mo. Production control samples with one original scale side and one ground side are analysed on both sides and the analytical results are compared. The values correlate with a coefficient of determination greater than 0.99 averaged over the observed elements

Laser Induced Breakdown Spectroscopy

“…Analytical curves with good correlations (r > 0.9, with the exception of sulfur) were obtained and detection limits in the range of 7 to 11 µg g -1 were found. In the second paper, 197 the elements quantified were C, P, S, Al, Cr, Cu, Mn and Mo. The performance of the triple-pulse configuration was compared with single-pulse and double-pulse configurations and an increase of detectivity was observed probably due to an enhancement of material ablation.…”

“…Sturm et al 196,197 and Vrenegor et al 198 investigated the use of the multi-pulse excitation LIBS in steel alloys. Triple laser pulses were generated by one laser source (modified to produce three separate lasers pulses) 196 or by two lasers sources (one producing double-pulses and other producing a single-pulse).…”

“…198 The main components of the LIBS systems were one 196,197 or two Q-switched Nd:YAG lasers 198 operating at 1064 nm with a pulse duration on the order of nanoseconds. The sample chamber was flushed with argon gas.…”

Application of Stand-off Double-Pulse Laser-Induced Breakdown Spectroscopy in Elemental Analysis of Magnesium Alloy

“…Many researchers designed and built collinear [22,23] or orthogonal [24,25] multi-pulse LIBS experiment systems, studied the characteristic under different conditions so as to obtain good signal intensity and stability. In addition, the stand-off LIBS technology which can analyze the sample from a certain distance is another research focus [26−28] .…”

Többimpulzusos lézer indukált plazmák jellemzése és atomspektroszkópiai alkalmazása

“…A kísérleteikhez használt Qkapcsolós Nd:YAG lézer három impulzus kibocsátására volt alkalmas, amely impulzusok energiája azonos, hosszuk pedig kb. 16 2004-es tanulmányukban felületi reve réteggel rendelkezı acélminták tömbfá-zisban történt analízisérıl számoltak be [132]. Az iparban az ilyen típusú mintákat általában SD-OES vagy XRF módszerrel vizsgálják be, azonban a mérések elıtt a felü-leti reve réteget csiszolással vagy maratással el kell távolítani.…”