Background The field of metallurgy utilises an ever-increasing array of steel and alloy compositions in addition to a large number of processing techniques employed in material production through to product finishing. Surface analysis has a role to play in the characterisation of these materials from their microstructure to large-scale customer complaints. The high sensitivity of techniques such as secondary ion mass spectrometry (SIMS) can be invaluable in establishing the material chemistry, particularly for low level additives, impurities or contaminants.
Benefits to Customer· Location of ppm/ppb levels of elements in microstructure
· Clear and precise determination of the cause of corrosion
· Potential detection of corrosion products before the appearance of visual evidence
· Detection of low levels of corrosion accelerators such as chlorine
Case Study: Microstructure of Treated SteelAn example of the use of secondary ion mass spectrometry (SIMS) to reveal microstructure can be seen in the image of boron and hydrogen obtained from boron doped (50ppm) stainless steel sample heat treated at 1070°C in a dissociated NH3 atmosphere. The heat treatment causes the formation of an almost uniform layer of boron nitride at the stainless steel surface which also extends for some distance into the bulk. SIMS imaging discloses not only the presence of hydrogen at the grain boundaries but also AlN, CrN, SiN and complex carbide-boride-nitrides