Effect of Coal Liquefaction Solvents on Fatigue Crack Initiation in 2 1/4 Cr-1 Mo Steel and 316L Stainless Steel

Blunt notch fatigue crack initiation tests were carried out on 2.25 Cr – 1 Mo steel and 316L stainless steel in room temperature air and in the process solvent from the Wilsonville, Alabama coal liquefaction pilot plant at 100°C. The crack initiation lifetime in the coal liquids at 100°C was an order of magnitude greater than the crack initiation lifetime in air for the 2.25 Cr–1 Mo steel. The crack initiation lifetime in the coal liquids for the 316L stainless steel was increased a factor of five over the crack initiation lifetime in air. The improvement in crack initiation lifetime was attributed to the coal liquids shielding the materials from atmospheric embrittlement. The coal liquids did not show any tendency to form sulfide corrosion products at 100°C.