Study of heterogeneities in steels and determination of soluble and total aluminium and titanium concentration by laser ablation inductively coupled plasma mass spectrometry

Abstract

A methodology for bulk analysis of Al and Ti and for determination of soluble and total Al and Ti concentration in steel samples by laser ablation inductively coupled plasma mass spectrometry was developed. The spatial distribution (both at surface and within the sample) of the insoluble fraction of Al and Ti was also qualitatively estimated. Certified reference materials (CRMs) SS-451 to 460 (carbon steel) and 064-1 (Nb/Ti interstitial free steel), from BAS, and JK 2D (carbon steel) and JK 37 (highly alloyed steel), from SIMR, were studied. It was demonstrated that the insoluble fraction of Al and Ti is heterogeneously distributed. A series of nine glass samples (fused beads) with fixed Fe content and different Al and Ti contents was prepared by melting appropriate amounts of Fe(2)O(3), Al(2)O(3) and TiO(2) with a lithium tetraborate-sodium carbonate mixture. Quantitative determinations were performed by using calibration graphs obtained from the synthetic fused beads, with (57)Fe as internal standard; line scan laser sampling mode was used, focusing the laser beam at the sample surface. The optimized laser operating parameters were: laser pulse energy of 1.5mJ, pulse repetition rate of 5Hz, scanning speed of 5microm s(-1) and preablation time of 20s. The concentrations obtained for bulk analysis of CRM samples corresponded with the certified values within the experimental uncertainty. An acceptable concordance between certified and found values was attained for the determination of soluble and total Al and Ti in CRM 064-1 sample.

A novel approach for the quantitative analysis of multiple elements in steel based on laser-induced breakdown spectroscopy (LIBS) and random forest regression (RFR)

“…In order to get a better quantitative performance, some simple pre-processing 80 methods(i.g smooth and de-noise) based on five points moving-average were used to improve the signal-to-background ratio validated by OOB estimation and 10-fold cross validation(CV). conjunction with the 10-fold and out-of-bag cross-validation 5 statistics, suggests that the model is useful for quantitative analysis of multi-elements in steels.…”

“…Relationship of OOB error rate with ntree and mtryTable 3shows the correlation coefficients(R) and root mean square error(RMSE) with different input data of RFR model by5 means of OOB estimation and 10-fold CV. As seen asFig.…”

Application of Laser Ablation ICP Mass Spectrometry for Analysis of Oxide Particles on Cross Section of Alloys and Steels

“…Since the ion intensity signal is directly proportional to the mass of element in ablated metal, the IAl(Me+P)/IAl(Me) ratio can be evaluated from Eqs. (8) and (9) as follows:…”

“…Other candidates for the rapid analysis of inclusion particles on a surface of steel sample are a Laser Ablation-Inductively Coupled Plasma-Atomic Emission Spectrometry (LA-ICP-AES) and a Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). In recent years, the LA-ICP-MS was applied for the direct analysis of steels and alloys concerning to the determination of the bulk composition, [5][6][7][8] the content of soluble and insoluble elements 7,8) the spatial and surface distribution of elements in steels and alloys, 8,9) and the mapping analysis of inclusions. [10][11][12][13][14] In this study, the LA-ICP-MS method is applied for the estimation of oxide particles containing Al2O3, MgO and other oxides on the cross section of Fe-10 mass% Ni alloy.…”

Laser ablation‐inductively coupled plasma mass spectrometry in archaeometric research

“…The use of the line‐profiling mode permits covering a wider area (typically some millimeters), which results in more representative results for inhomogeneous samples (Morrison et al, 1995; Motelica‐Heino et al, 1998; Günther, Jackson, & Longerich, 1999). Moreover, sensitivity is often enhanced with line‐profiling because, in the drilling mode, the ablation rate and the particle transport efficiency decrease as the beam penetrates deeper into the sample (Mank & Mason, 1999; Coedo et al, 2007). Finally, some authors have pointed out that line‐profiling reduces elemental fractionation (Neff, 2003).…”