[1] Rosado DB, Waele WD, Vanderschueren D, Hertelé S (2013) Latest developments in mechanical properties and mettalurgical features of high strength line pipe steels. 5th Conf on sustainable construction and design 4(1): 10-22.

[2] API Specifications 5L (2008) Specification for Line Pipe. 44th edn. In: American petroleum institute.

[3] Hashemi SH, Mohammadyani D (2012) Characterisation of weldment hardness impact energy and microstructure in API X65 steel. Int J Pres Ves Piping 98: 8-15.

[4] ASTM standard E1820 (2002) Standard test method for measurement of fracture toughness. In: Annual book of ASTM standards.

[5] Farrahi A, Hashemi SH (2013) Experimental evaluation of fracture toughness in spiral seam weld of thermomechanical steel. Journal of Solid and Fluid Mechanics 2(4): 25-35. (In Persian)

[6] Chen X, Lu H, Chen G, Wang X (2015) A comparison between fracture toughness at different locations of longitudinal submerged arc welded and spiral submerged arc welded joints of API X80 pipeline steels. Eng Fract Mech 148: 110-121.

[7] Yang Y, Shi  L, Xu Z, Lu H, Chen X, Wang X  (2015) Fracture toughness of the materials in welded joint of X80 pipeline steel. Eng Fract Mech 148: 337-349.

[8] Hashemi SH (2008) Apportion of Charpy energy in API 5L grade X70 pipeline steel. Int J Pres Ves Piping 85(12): 879-884.

[9] Hashemi SH, Mohammadyani D, Pouranvari M, Mousavizadeh SM (2009) On the relation of microstructure and impact toughness characteristics of DSAW steel of grade API X70. Fatigue Fract Eng Mater Struct 32(1): 33-40.

[10] Herrera DA, Hernández AA, Meléndez RC, Velázquez JL (2014) Fracture toughness in the circumferential–longitudinal and circumferential–radial directions of longitudinal weld API 5L X52 pipeline using standard C(T) and nonstandard curved SE(B) specimens. Int J Fract 188(2): 251-256.

[11] Neves BeltrÃO MA, Castrodeza E, Bastian FL (2010) Fatigue crack propagation in API 5L X‐70 pipeline steel longitudinal welded joints under constant and variable amplitudes. Fatigue Fract Eng Mater Struct 34(5): 321-328.

[12] Hashemi SH, Sedghi S, Soleymani V, Mohammadyani D (2012) CTOA levels of welded joint in API X70 pipe steel. Eng Fract Mech 82: 46-59.

[13] ASTM standard A370-14 (2014) Standard test methods and definitions for mechanical testing of steel products. In: Annual book of ASTM standards.

[14] Hashemi SH, Sabokrouh M, Farahani MR (2013) Investigation of weldability in multi-pass girth welding of thermomechanical steel pipe. Modares Mechanical Engineering 13: 60-73. (In Persian)

[15] Server WL (1978) General Yielding of Charpy V-Notch and Precracked Charpy Specimens. J Eng Mater Tech 100(2): 183-188.

[16] Sreenivasan PR, Ray SK, Samuel KG, Mannan SL (1992) An empirical relation between yield stress and general yield load for a charpy U-notch specimen. Eng Fract Mech 42(6): 1047-1049.

[17] British standard BS 7448-4 (1997) Fracture mechanics toughness tests–method for determination of fracture resistance curves and initiation values for stable crack extension in metallic materials.