Danger of Fragmentation Failures of Composite Gas Fuel Cylinders with Micro- and Macrodamages of Inner Metal Shell

Abstract

Abstract Gas fuel cylinders (GFCs) for motor vehicles are a source of man-made danger with such damaging factors as thermal radiation, open flame, as well as shock air waves and fragments in a case of an explosive nature of depressurization. To increase reliability of GFC, it is urgent to study causes of their fracture under various conditions of operation, in particular in a cryolithozone. A purpose of this paper is analysis the fragmentation of GFC to identify factors affecting safety of operation of gas cylinder vehicles in the sharply continental climate conditions. A character and causes of premature destruction of two metal-composite cylinders for compressed natural gas, occurred in winter and summer time, were investigated. It is found that the destruction was induced by defects of an inner steel shell of the cylinders (mechanical damage, presence of a decarburized layer, and hydrogen degradation), which caused initial cracks formation according to a fatigue mechanism. The main natural and climatic factor that stimulated reaching a state of overload in GFC with the defects of the inner shell was environment temperature fluctuations. Results of the paper can be used to improve operational capability of GFC, to ensure the safety of their operation and development of compensatory measures.