An 8 in. diam stainless steel black liquor feed pipe to a carbon steel digester had failed within one year of service. The material was type 316 molybdenum-containing austenitic stainless steel. The service environment was alkaline black liquor at 175 deg C (350 deg F). The pipe had developed cracks on the inside surface coincident with an external support gusset. The cracks initiated at wide corrosion grooves. The early stages were corrosion-assisted fatigue cracks. The cracks initiated at the corrosion grooves and propagated as transgranular SCC with characteristic branching. Evaluation indicated the cracks were localized in an area of...
D. G. Chakrapani, Failure of a Stainless Steel Black Liquor Feed Pipe, ASM Failure Analysis Case Histories: Pulp and Paper Processing Equipment, ASM International, 2019, https://doi.org/10.31399/asm.fach.pulp.c9001564
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