Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters

Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties pipes, their fracture behaviour, depend on the characteristics both, base metal, and weld metal. In this work, two seam pipes are considered having diameters manufactured P235TR1 steel. Hardness microstructure were examined samples which contained zone, to capture influence heterogeneity. Fracture resistance pipeline material, i.e. both metals seams, was determined by experimental examination recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between tested heterogeneity caused joint, comparison crack growth curves. Effects initial concentrator shape, machined or fatigue pre-crack discussed.