Analysis of the ductility dip cracking in the nickel-base alloy welding overlay on heat exchanger tube sheet

Liu, Tong; Wang, Qiongqi; Guan, Kaishu

doi:10.1016/j.engfailanal.2023.107158

Cited by 3 publications

(2 citation statements)

References 19 publications

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“…These methods are based on different restraint conditions and involve observing post-weld cracking. Additionally, thermal simulation is used to study the tendency for weld seam cracking [17]. Due to the complexity of the constrained conditions in samples, which are pipes in this case, the thermal simulation method is employed to investigate the microstructure of different regions in the weld and the evolution of maximum hardness.…”

Section: Thermal Simulation Testmentioning

confidence: 99%

Failure Analysis of Cracked P110 Repaired Tubing Used for Gas Transmission

Zhang,

Xie,

et al. 2023

Materials

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With green and low-carbon developments in oil fields, an increasing amount of repaired oil tubing is being used as oil and gas transmission pipelines in China. However, due to differences in manufacturing standards between oil tubing and transmission pipelines, there are inevitably some issues during their use. This paper investigates a case of cracking failure in repaired oil tubing used as a gathering and transportation pipeline. The failure occurred after eight months of operation and was characterized by a circumferential crack at the male thread end of the tubing joint. To determine the root cause of the failure, a series of experiments were conducted on the oil tubing. The experiments included visual inspection, chemical composition analysis, mechanical properties testing, hardness testing, metallographic examination, and microstructure analysis. The results revealed that the thread of the cracked tubing was not tightened to the specified position; the connection between the tubing and the coupling was welded in a circumferential direction; and cracks occurred in the heat-affected zone of the weld. Chemical composition, tensile performance, and the Charpy impact of the tubing meet the requirements of API 5CT for P110 material, and no abnormalities were found in the metallographic structure. The microstructure at the weld toe of the fracture is martensite, and the hardness is 476 HV10. Based on the thermal simulation verification test, when the material of the tubing cools from 1200 °C, which is located in the coarse HAZ temperature zone, the base metal transforms into martensite with a little granular bainite, exhibiting its highest hardness value at 371 HV10, which is higher than the allowable hardness for carbon steel and indicates the material has poor weldability. The reasons for the cracking and failure of the tubing are that the P110 repaired tubing has a high carbon equivalent and poor weldability. During the welding process, martensitic structure was formed at the weld toe, and cold cracks appeared in the heat-affected zone, resulting in failure. To avoid the reoccurrence of such failure, recommendations are proposed.

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Section: Thermal Simulation Testmentioning

confidence: 99%

Failure Analysis of Cracked P110 Repaired Tubing Used for Gas Transmission

Zhang,

Xie,

et al. 2023

Materials

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“…It has been shown in the literature that excessive and prolonged hydrogen is one of the main causes of failure in heat exchanger materials in oil production, such as duplex stainless steels (Li et al, 2023a(Li et al, , 2023b and austenitic stainless steels (Kadoi et al, 2023). The high-temperature Incoloy 825 is also frequently used in the manufacture of hydrogenation heat exchangers because of its excellent corrosion resistance and mechanical properties (Liu et al, 2023).…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrogen on the pitting corrosion behavior of Incoloy 825

Li,

Yao,

Guan

et al. 2024

ACMM

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Purpose In this paper, the authors aim to study the effect of hydrogen on the pitting corrosion behavior of Incoloy 825, a commonly used material for heat exchanger tubes in hydrogenated heat exchangers. Design/methodology/approach The pitting initiation and propagation behaviors were investigated by electrochemical and chemical immersion experiments and observed and analyzed by scanning electron microscope and energy dispersive spectrometer methods. Findings The results show that hydrogen significantly affects the electrochemical behavior of Incoloy 825; the self-corrosion potential decreased from −197 mV before hydrogen charging to −263 mV, −270 mV and −657 mV after hydrogen charging, and the corrosion current density increased from 0.049 µA/cm2 before hydrogen charging to 2.490 µA/cm2, 2.560 µA/cm2 and 2.780 µA/cm2 after hydrogen charging. The pitting susceptibility of the material increases. Originality/value Hydrogen is enriched on the precipitate, and the pitting corrosion also initiates at that location. The synergistic effect of hydrogen and precipitate destroys the passive film on the metal surface and promotes pitting initiation.

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