Airborne emissions and corrosion of stainless bellows under simulated semiconductor halide environment

Stainless steel bellows in semiconductor pump-scrubber systems are prone to halide-induced corrosion, releasing airborne fine particles and transition metals. This study examined the emissions and surface degradation of AISI 316Ti and Alloy 926 under simulated halide-rich conditions over 72 h. Particle size distributions were measured using a Scanning Mobility Particle Sizer and Optical Particle Sizer; surface morphology and pit depth were analyzed via stereo microscopy and SEM-EDS. Airborne metals were collected with a three-stage cascade impactor and quantified by ICP-MS; halide ions were determined by ion chromatography. After 72 h, peak particle diameters were 850 nm for 316Ti and 950 nm for Alloy 926, with respective concentrations of (3.861 ± 0.772) × 10⁷ and (5.913 ± 1.183) × 10⁶ particles/cm³ . Total airborne Cr from 316Ti reached (1.168 ± 0.189) × 10⁴ µg/m³ , exceeding the occupational exposure limit for Cr(VI) (1 µg/m³) and indicating a clear inhalation hazard. Surface examination revealed pit depths of 3-15 µm for 316Ti, compared with 0.5-3 µm for Alloy 926.The 72 h exposure simulated cumulative halide loading and environmental release potential in mixed halide fluoride/chloride (F⁻/Cl⁻) conditions observed in wet and burn-wet scrubbers. Findings provide emission data for predictive environmental and occupational exposure modeling, supporting corrosion-resistant alloy selection, proactive maintenance, and inspection strategies to mitigate airborne contamination in high-tech manufacturing.