Steel analysis: ARL X900 Simultaneous/Sequential X-Ray Fluorescence Spectrometer

Importance of the Topic

Ferrous base materials are fundamental to construction, automotive and manufacturing industries, requiring precise chemical analysis for quality and compliance.

Objectives and Study Overview

• Assess analytical performance of the Thermo Scientific ARL X900 Series for steel analysis using wavelength dispersive X-ray fluorescence (WDXRF).
• Determine limits of detection, precision, repeatability and accuracy across various steel matrices.

Methodology and Instrumentation

The ARL X900 spectrometer combines fixed monochromator channels (up to 32) and a proprietary Moiré fringe goniometer for simultaneous-sequential WDXRF analysis.
Key features include:

• High-power X-ray tube (up to 4200 W) with dual detectors (flow proportional counter and scintillation).
• Fixed channels for major alloy elements and optional high-counting channels for Ni, Co and Mo.
• Counting times of 20 s for routine throughput and 100 s for enhanced detection limits.
• Calibration using certified reference materials and user samples for turnkey installation.

Main Results and Discussion

Limits of detection in an iron matrix ranged from below 1 ppm for trace elements (e.g., Mo 0.8 ppm at 100 s) to tens of ppm for heavier elements (e.g., Ta 9.3 ppm at 100 s).
Short-term precision tests (20 s counting) yielded relative standard deviations below 0.01 % for major components and below 2 % for trace levels. Long-term repeatability over 38 h demonstrated stability within 0.005 %–0.01 % RSD for key alloying elements. Accuracy evaluation against five reference materials showed deviations below 0.05 % for major constituents and within 0.1 % for minor elements.

Benefits and Practical Applications of the Method

• Rapid multi-element analysis in under one minute, supporting high-throughput workflows.
• Excellent precision and accuracy across diverse steel grades, from low-alloy to high-alloy and stainless steels.
• Turnkey calibration reduces commissioning time and simplifies routine QA/QC and R&D tasks.
• Versatile instrumentation accommodates a wide element range from boron to californium.

Future Trends and Opportunities

• Integration with automated sample handling and process control systems.
• Advanced data analysis and artificial intelligence for real-time quality monitoring.
• Expanded fixed-channel libraries and improved detector technologies for lower detection limits.
• Adoption in additive manufacturing and on-site metallurgical analysis.

Conclusion

The Thermo Scientific ARL X900 Series offers robust, precise, and accurate XRF analysis of ferrous materials with minimal setup, high throughput and flexible instrumentation, making it ideal for both routine production monitoring and advanced research applications.

References

• Thermo Scientific Application Note AN41423: X-ray Fluorescence Steel Analysis with ARL X900 Series