Spectrochemical Analysis of Stainless Steel Using 355 nm and 1064 nm Nd:YAG Laser-induced Breakdown Spectroscopy

Stainless steel is a notably beneficial product and is widely used in many applications. Controlling the quality of steel products by determining their trace elemental content is essential. The content of trace elements such as Cr in steel protects the alloy from corrosion and enhances its lifetime, especially in the case of steel embedded in concrete structures. This article presents a quantitative analysis of the trace element Cr in steel samples using advanced laser-induced breakdown spectroscopy (LIBS) with an Nd:YAG laser at wavelengths of 355 and 1064 nm. The LIBS emission intensity of Cr at a laser wavelength of 355 nm was improved compared to that at 1064 nm. Notably, the calibration curves exhibit a zero intercept using the LIBS technique at the third harmonic (355 nm) and fundamental (1064 nm) wavelengths generated by the Nd:YAG laser. The detection limits for Cr in steel were determined as 21 and 36 parts per million using the laser wavelengths of 355 and 1064 nm, respectively. This study demonstrated that the wavelength of 355 nm is significantly more suitable for the quantitative analysis of stainless steel than 1064 nm in laser-induced spectroscopy.