Bulk Analysis of Stainless Steels (Corrosion and Heat-Resistant Steels)

Significance of the Topic

Stainless steels are widely used in environments demanding corrosion and heat resistance across industries from chemical processing to energy production Precise control of alloy composition is critical to meet performance specifications and to manage raw material costs Routine bulk analysis ensures that both producers and end users verify material grade and prevent costly failures

Objectives and Study Overview

This application note assesses the performance of the LECO GDS900 glow discharge atomic emission spectrometer for rapid and accurate determination of major and trace elements in various stainless steel grades The goals include evaluation of analytical precision, calibration linearity, sample throughput, and instrument stability under production conditions

Methodology

Sample Preparation Stainless steel specimens were ground using a 120 grit zirconium oxide belt or polished with a wet disk Accessories included a LECO BG belt grinder and LECO PX polisher

Calibration and Drift Control Calibration curves for elements such as chromium and nickel were established with certified reference materials from suppliers including Brammer ARMI NIST and MBH Homogeneous setup standards were employed for drift correction to maintain accuracy over extended runs

Analysis Protocol Glow discharge sputtering removes material uniformly without melting the surface Up to three discrete analyses can be performed in a single spot within 90 seconds Typical cycle times include a 60 second start up and preburn followed by three 10 second measurements

Instrumentation Used

• LECO GDS900 atomic emission spectrometer with glow discharge plasma and CCD detection
• LECO BG belt grinder and LECO PX polisher for sample surface preparation

Main Results and Discussion

Precision and accuracy were demonstrated across a range of stainless steel families including ferritic austenitic and precipitation hardened grades such as 410 316L 347 303 17-4PH and 17-7PH Major alloying elements exhibited relative standard deviations below 1 percent Trace elements including sulfur and boron showed RSD values typically under 5 percent Calibration curves were inherently linear over wide concentration ranges and no spectral carryover was observed

Benefits and Practical Applications

• High throughput analysis supports rapid quality control and production monitoring
• Linear response across trace to high concentration simplifies method setup
• Nonmelting glow discharge source enables reliable analysis of volatile species such as sulfur
• Reduced spectral interferences deliver robust results for complex alloy matrices

Future Trends and Potential Applications

Advances may include expansion of glow discharge techniques to nonferrous and advanced alloy systems Integration with automated sample handling and inline process control can further increase throughput Analytical software enhancements and machine learning approaches are poised to improve spectral deconvolution Development of compact portable instruments may enable field analysis in remote or on site environments

Conclusion

The LECO GDS900 glow discharge atomic emission spectrometer offers reliable rapid and precise bulk analysis of stainless steels Its linear calibration performance high throughput capability and reduced spectral interferences make it a valuable tool for both material producers and end users seeking to verify alloy composition and ensure product integrity

References

• LECO Corporation Form No 203-821-576 Bulk Analysis of Stainless Steels 2019
• Certified Reference Materials from Brammer ARMI NIST and MBH