Elizabeth C. Buc, PhD, PE, CFI
Fire and Materials Research Laboratory, LLC, USA
Presented at International Symposium on Fire Investigation, 2012
NFPA 921 Guide for Fire and Explosion Investigations recognizes the need for specialists for certain aspects of fire cause investigations. One such area is metallurgical failure analysis. Examples of metallurgical aspects that overlap the fire investigation field include vessel and pipeline failures from corrosion or welded joint failures causing loss of containment (i.e., natural gas); wear and mechanical breaks or failures that generate sparks or frictional heating that cause ignition; and elucidation of heat or fire versus electrical arc damage to current carrying components, such as conductors, motor windings, contacts, and fuses. Equally important, metallurgy can be used to determine the effects of fire on low-melting temperature alloys, such as brass and brazed joints, to determine when damage occurred and if it contributed to the cause of a fire or was a result of fire exposure. Like fire investigation, metallurgical root-cause failure analyses are performed according to a recognized professional standard methodology that meets the criteria for admissibility. Here, key elements of a metallurgical-based failure analysis are highlighted with specific metallurgical-based fire cause investigation case studies.