Corrosion fatigue crack growth of laser additively-manufactured 316L stainless steel in high temperature water. (October 2017) - Lou, Xiaoyuan
Highlights: Stress-relieved additively-manufactured (AM) 316L stainless steel shows columnar microstructure and anisotropic corrosion fatigue cracking behaviour with the fast crack path along the building direction. Solution-annealed AM 316L stainless steel shows equiaxed microstructure and similar corrosion fatigue crack growth rate to its wrought counterpart. Retained unrecrystallized grains in the high-temperature annealed AM 316L stainless steel shows minimum impact on the corrosion fatigue crack growth behaviour. As the loading frequency decreases, the effects of material conditions created by heat treatment, crack orientation and applied cold work slightly increased. High-temperature recrystallization annealing may be necessary to AM 316L stainless steel for nuclear applications Abstract: Corrosion fatigue crack growth of laser additively-manufactured 316L stainless steel was studied in oxygenated 288 °C water. Effects of heat treatment, crack orientation, and applied cold work were evaluated. Stress-relieved material showed higher crack growth rate than annealed material. Their difference was not significant when the loading frequency was high. When the loading frequency decreased, the effects of material conditions created by heat treatment, crack orientation and applied cold work slightly increased. Retained unrecrystallized grains in an annealed material did not affect significantly the cracking susceptibility. High-temperature recrystallization treatment of an AM 316L component may be necessary for nuclear applications.