InSitu Analysis of Pipeline Metallurgy - dnV

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Where TT = Charpy transition temperature (°C)Si = silicon (%)Nf = free nitrogen content (%)P = phosphorous (%)d = ferrite grain size (mm)DNV (4) staff have observed that the relationship of toughness data to pipeline composition data derivedfrom OES analysis can be relatively consistent for pipes within a single population of pipe joints.However, for other populations of pipe different relationships of toughness to composition appear to fitbetter.Methods based on the automated ball indentation (ABI) test technique have been described andevaluated by various researchers and service providers. 12 The ABI method is nondestructive andcapable of measuring data regarding true stress-true strain characteristics from which tensile propertiescan be derived. More recent work has been aimed at demonstrating the ability to derive fracturetoughness properties as well. We have found no North American or European standard that covers theuse of ABI methods for measurement of tensile or fracture toughness properties.The power generation industry has used small punch test (SPT) specimens to estimate tensile andfracture toughness properties, but the procedures are not yet standardized by ASTM (5) or standardsorganizations in the European Union. The specimens encompass a range of sizes and shapes, agenerally ranging in size from 3 to 10 mm (0.12 to 0.40 in.) in diameter and between 0.1 to 0.75 mm(0.004 to 0.03 in.) thick. 13 Although the specimen thickness is small, a considerable amount of the wallthickness of a typical transmission pipeline could be affected by the machining operation that removesthe required material from which the specimen is made.(4)Det Norske Veritas (USA), Inc., 5777 Frantz Rd. Dublin, OH 43017.(5) ASTM International, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959.
ScratchesFigure 3:Typical appearance of the outsidesurface of seams made by A.O. Smith fromabout 1928 through about 1932. (Scale ininches)GrooveFigure 1: Surface of continuous butt weldseam pipe showing characteristic grooveand band of subtle scratches. (Scale ininches)Figure 4:Typical in-field use of portable OESchemical analysis equipment.1 in. (25mm)Figure 2: Stamp marks near the end of aseamless pipe identifying the manufactureras Youngstown Steel & Tube Co.
Page 1 and 2: In-situ Analyses to Characterize th
Page 3 and 4: careful removal of coating and clos
Page 5 and 6: from a pipe having a nominal origin
Page 7: In-situ MetallographyIn-situ metall
Page 11 and 12: Figure 10: Magnified view of a norm
Page 13 and 14: 11. B.L. Bramfitt, “Structure/Pro

InSitu Analysis of Pipeline Metallurgy - dnV

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