Quantitative Analysis of Total and Insoluble Elements and Inclusion Composition in Metal by Laser Ablation ICP-MS Method.

Abstract

The development of a rapid and accurate method for determining soluble and insoluble contents of elements and inclusion composition is indispensable to the quality control of steels. The laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) has been successfully applied to the direct analysis of steel composition [1][2][3][4][5][6] and to the determination of trace element concentrations in geological minerals and rocks. [7][8][9][10][11][12] The LA-ICP-MS technique is characterized by the quick analysis with high precision (approximately 5 to 15% for most of elements). 1,4,5,[8][9][10][11][12] Up to now, only total concentration of elements in a metal sample has been determined by this technique, but the application to the analysis of inclusion composition has not been made despite of the fact that the accurate control of inclusion composition is of considerable importance to the high quality steel production.This study is concerned with the application of the LA-ICP-MS technique to the quantitative analysis of total (M total ) and insoluble (M insol Apparatus and Operating ConditionsThe Hewlett-Packard HP 4 500 inductively coupled plasma mass spectrometer with the LSX-100 laser ablation system was used for the analysis of metal samples.A schematic diagram of the LA-ICP-MS system is shown in Fig. 1. A sample is sealed in an ablation chamber where it is irradiated by a laser under flowing Ar carrier gas. The Nd:YAG laser is operated in Q-switched mode, producing a highly collimated beam (Ͻ0.8 mrad divergence) and near-Gaussian beam energy profile. The laser beam focuses onto the sample surface via the objective ISIJ International, Vol. 41 (2001) KEY WORDS: quantitative analysis; steel; total and insoluble elements; inclusion composition; laser ablation ICP-MS.

Analysis of Composition and Size Distribution of Inclusions in Fe-10Mass%Ni Alloy Deoxidized by Al and Mg Using Laser Ablation ICP Mass Spectrometry

“…The precision and accuracy of the LA-ICP-MS analysis is found to be 2 to 5 % for Al 2 O 3 , MgO and CaO content in synthetic particles of CaO-Al 2 O 3 , CaO-Al 2 O 3 -MgO and MgO-Al 2 O 3 systems. 1,2) The difference between the size of synthetic particles in the range of 10Յd V Յ40 mm obtained by LA-ICP-MS and that by SEM is on the average 1.7 mm by using Al 2 O 3 calibration line and 2.4 mm by using MgO calibration line. 3) In this study, the LA-ICP-MS has been used for the determination of the inclusion composition and size distribution of oxide particles with d V Ͻ10 mm in an Fe-10mass%Ni alloy deoxidized by Al followed by Mg and Mg followed by Al addition.…”

“…Detailed explanation and some characteristics of LA-ICP-MS system are already given in previous article. 1,3) The standard samples and metal samples were ablated and analyzed by using the following parameters; laser scan rate of 0.01 mm/s, laser energy of 2.0 mJ/shot, frequency of laser shots of 20 Hz, defocus of laser beam of 0 mm, and integration time of 0.1 or 0.01 s. The width and depth of laser track on metal surface were on the average 25 and 50 mm, respectively at given ablation parameters. Total ablated area was 0.7 to 1.0 and 0.2 to 0.4 mm 2 for the samples in Exp.…”

“…The analysis of standard samples was made every 1 h since the slope of calibration line changes with ablation time. 1,3) …”

“…1,3) In this study, the size of cluster observed on film filter by SEM was estimated by using image analyzer as equivalent-area diameter of a circle having the same area as a measured cluster. In LA-ICP-MS measurement, the size of cluster in metal was estimated as spatial diameter of hypothetical sphere having the same volume as an ablated cluster.…”

“…In previous works, [1][2][3][4][5] it has been demonstrated that the composition and size of oxide particles in metal and other materials can be measured by using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The precision and accuracy of the LA-ICP-MS analysis is found to be 2 to 5 % for Al 2 O 3 , MgO and CaO content in synthetic particles of CaO-Al 2 O 3 , CaO-Al 2 O 3 -MgO and MgO-Al 2 O 3 systems.…”