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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Evaluation of DOT 3AL 6061-T6 Cylinders to Determine the Crack Initiation Site (CIS) Which Were Detected in Cylinder's Neck Threads

August 19, 2010

This research project is a part of Failure Investigation and Metallurgical Analysis of DOT 3AL cylinders that were rejected during requalification due to internal neck-cracks. The main purpose of this research was to analyze the cylinder heads in order to determine the crack initiation site (CIS), crack type, the extent of crack propagation and the common cause of this type of cracks. The results of this research and fatigue analysis have been used to assess root-cause of neck-cracks and determination of safe usage of other DOT 3AL cylinders of the same lot in transportation.

This research project has been initiated and managed by DOT/Hazardous Materials Technology. For technical question, contact Mr. Mark Toughiry, 202-366-4545