Analysis of Welding electrodes with the Thermo Scientic NITON

®

XL3t 800 Series

NITON XL3 Series Handheld Analysers — Simply Superior XRF

Application Method Several types of welding electrodes are produced for specic applications and are available in different sizes and compositions. For example, tungsten (W) electrodes are used for tungsten inert gas (TIG) welding and usually have an added element to improve performance. These elements include zirconium (Zr), thorium (Th), cerium (Ce), and lanthanum (La) at concentrations up to 2 percent. The Thermo Scientic NITON XL3t analyzer with its powerful 50 kV x-ray tube can be used to quantify these elements in welding electrodes for both quality control (QC) and positive material identication (PMI). Selecting the correct tungsten electrode is necessary for producing high-quality welds. Rods with the wrong additive element, or with incorrect amounts of the specied element (out of specication), can damage the work, leading to lost production time and costly rework.
F or this application study, four types of electrodes were analyzed: pure tungsten, thorium dioxide doped tungsten, cerium dioxide doped tungsten, and lanthanum oxide doped tungsten. The electrodes were analyzed as received from the supplier using an XL3t 800 Series alloy analysis. Five 30-second readings were taken of the sample electrodes. Results Table 1 shows the results obtained from the XL3t 800 Series instrument. The concentration range specied by the manufacturer for each type of electrode is given in the second column. The values obtained for each element are given along with the 95 percent condence interval in the remaining columns.
EWTh-21.6-1.9 Th1.8 +/-0.08Table 1: Comparison of manufacturer’s-specified range with NITON Xrf analysis results, based on the average of five 30-second readings for each electrode