Time-variant burst strength of pipe with corrosion defects considering mechano-electrochemical interaction

Experimental study of the effects of semi-elliptical defects on the API X52 pipeline and its reparation by welding

“…journal.ump.edu.my/jmes ◄ At the semi-elliptical form a/t = 0.2 as the first casewhere the maximum value of stress reached to 488 MPa and its elongation 12.71%, in the second form is considered by the ratio of a/t = 0.5, where the stress is 311MPa and its elongation 7.36%, in the third form a/t = 0.8, where the stress is 160 MPa and its elongation 1.98 %. The obtained results explain that the crack phenomenon with semi-elliptical form lead to crack API X52 pipeline which characterized by a reduction of the ultimate stress from the value of 558 MPa for the base metal specimen to 160 MPa for the cracked specimen [17][18][19]. Depending on these characteristics, which have directly relationship with specimen with defect of the depth (a), where the elongation value decreased from 40.86% to 1.98% led to degradation of piping systems.…”

“…In order to show the effect of crack on the piping systems through the ratio 0<a/c ≤1, where the experimental results clearly explain that the various forms of semi-elliptical of the defected specimens are lower resist than the base metal specimen. Figure 12 clearly explained that the difference between the both results of the ultimate stresses are very significantly, where three ratios (a/c) for 1, 0.7 and 0.4 of defected specimens gave values of 311 MPa, 306 MPa and 259 MPa, respectively which compared with the base metal specimen of 558 MPa [17][18][19]. journal.ump.edu.my/jmes ◄ In order to reach an explanation of the semi-elliptical defects through the ratio a/c that the experimental results of the ultimate stresses for three shapes of 0<a/c≤1 are lower than the experimental result of the base metal specimen as shown in the Figure 12.…”

“…In addition, the corrosion phenomenon which is one of the dangerous advanced steps, leads to weak of the structures of the piping systems and damaged under burst pressure of defects general corrosion [14,15], including the small cracks or different cracks that become critical zones [15,17]. Due to the occur of the complex chemical reactions, the corrosion issue in the piping systems influenced to loss of mineral represented by the brown layer and to decrease of the thickness in lifetime, where the pitting forms change and turn into semi-elliptical depth or length depending on the nature of materials and operating conditions [17][18][19]. These problems have become great obstacles on the piping systems including elbows [19][20][21], valves, and components of piping installations, where many studies were performed the impact of defects on the structures, which lead to change the mechanical characteristics, thus it must need to repair by welding [20][21][22][23] or by material composites [23][24][25][26].…”

Numerical Simulation of Fretting Fatigue Damage Evolution of Cable Wires Considering Corrosion and Wear Effects

“…The corrosion morphology and fracture strength of the wire rope with time change were obtained. Wang et al [12] established a numerical model of mechano-electrochemical interaction, and studied the influence of single and two adjacent local corrosion defects on the burst strength of pipelines. Then they assessed the buckling behavior of axial compressed H-shape column with time-variant corrosion defects, based on the userdefined UMESHMOTION subroutine, the rules of corrosion morphology and collapse force of axial compression H-shape column changing with time are obtained [13].…”