Fracture behavior of carbon steel pipe with local wall thinning subjected to bending load

To evaluate the structural integrity of power plant piping, munotonic bending tests are conducted on 4- and 3.5-in. diameter full-scale carbon steel pipe specimens with local wall thinning. The local wall thinning is simulated as erosion/corrosion metal loss. The eroded area olʹ the wall thinning is subjected to tensile or compressive stress by applied bending moment. The deformations or fracture behaviors at maximum moments are found to be classified into three types. When the eroded area is subjected to tensile stress, ovalization or crack initiation/growth occurs at the maximum moment. When an eroded area is subjected to compressive stress, ovalization or local budding occurs. The occurrence of ovalization, crack initiation/growth, or local buckling depends on the initial size olʹ local wall thinning. From the relationships among ovalization, crack growth and local buckling, allowable sizes for local wall thinning arc proposed. © 1999 Elsevier Science S.A. All rights reserved.