Shahrood University of Technology Journal of Solid and Fluid Mechanics 2251-9475 2 4 2013 09 03 Experimental Evaluation of Fracture Toughness in Spiral Weld of Thermomechanical Steel Pipe Experimental Evaluation of Fracture Toughness in Spiral Weld of Thermomechanical Steel Pipe 25 35 157 10.22044/jsfm.2013.157 FA Ali Farrahi Journal Article 2012 09 09 Assessment of fracture toughness in pipe weldment is important for pipeline engineers and designers as welded zone is the most critical site for crack initiation and propagation. This research reports the determination of fracture toughness in spiral seam weld of API X65 pipe steel. This steel pipe has vast usage in Iran’s gas transportation projects. To measure the material fracture toughness, single edge notch bend (SENB) specimens were machined from the pipe. For evaluating the fracture toughness in test material, two techniques were used (based on multi-specimen tests in ASTM E 1820 standard). These techniques were based on determination of crack tip opening displacement (CTOD), and JIC. A value of 0.23 mm was obtained for CTOD, and its equivalent KIC was 265 MPa√m from the first method. The second test method gave a value of 396 KJ/m2 for JIC, whose equivalent KIC was 332 MPa√m. A discussion on the reasons for KIC difference from the two test techniques, and comparison between the obtained results and similar data from the literature conclude the paper. Assessment of fracture toughness in pipe weldment is important for pipeline engineers and designers as welded zone is the most critical site for crack initiation and propagation. This research reports the determination of fracture toughness in spiral seam weld of API X65 pipe steel. This steel pipe has vast usage in Iran’s gas transportation projects. To measure the material fracture toughness, single edge notch bend (SENB) specimens were machined from the pipe. For evaluating the fracture toughness in test material, two techniques were used (based on multi-specimen tests in ASTM E 1820 standard). These techniques were based on determination of crack tip opening displacement (CTOD), and JIC. A value of 0.23 mm was obtained for CTOD, and its equivalent KIC was 265 MPa√m from the first method. The second test method gave a value of 396 KJ/m2 for JIC, whose equivalent KIC was 332 MPa√m. A discussion on the reasons for KIC difference from the two test techniques, and comparison between the obtained results and similar data from the literature conclude the paper. https://jsfm.shahroodut.ac.ir/article_157_8e7f6a835d129f05a39f7e66f33960e2.pdf