Fracture failure analysis and research on solid expandable tubular with joint thread. (November 2021)

• Record Type: Journal Article
• Authors: Shi, Changshuai; Tan, Ling; Zhu, Xiaohua; Chen, Kailin; Cheng, Feilong
• Is Part Of: Engineering failure analysis. Volume 129(2021)
• Publication Date: 2021-11
• Subjects: Solid expandable tubular (SET) -- Thread -- SEM -- Failure analysis -- Finite element analysis; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2021.105658
• Languages: English
• ISSNs: 1350-6307

Abstract

Highlights: The expansion tube thread joint bears great stress in the expansion process. 316L steel is more suitable for expansion tube material than 20G steel. Irregular deformation of threads leads to stress concentration during process. Expansion tube thread joints are at great risk of fracturing during expanding. Threaded joints need materials with strong plastic deformation ability and high strength. Abstract: Fracture failure occurred in solid expandable tubular with thread joint during bulging experiment. The mechanical properties and microstructure of fracture shell were investigated by scanning electron microscopy and tensile test. Tensile tests show that the plastic deformation capacity and strength of box thread joint material (AISI 316L) are better than that of pin thread joint material (SAE 1020). Dimples and cleavage facets can be observed in the fracture surface. The finite element analysis shows that the threaded joints carry great compressive stress in the axial and annular directions during the solid expandable tubular bulging. The irregular deformation of the threaded joints during bulging leads to stress concentration at the thread root. There is a great risk of cracking in the case of insufficient strength thread material, and finally leads to the fracture of the joint thread.