Low temperature impact toughness of the main gas pipeline steel after long-term degradation

Abstract

Abstract:The correlation of microstructure, temperature and Charpy V-notch impact properties of a steel 17G1S pipeline steel was investigated in this study. Within the concept of physical mesomechanics, the dynamic failure of specimens is represented as a successive process of the loss of shear stability, which takes place at different structural/scale levels of the material. Characteristic stages are analyzed for various modes of failure, moreover, typical levels of loading and oscillation periods, etc. are determined. Relations between low temperature derived through this test, microstructures and Charpy (V-notch) toughness test results are also discussed in this paper.

Deformation and Energy Parameters of Fracture of Steel of the Main Gas Pipeline

“…The results obtained by the authors assist in improving the validity of monitoring the condition of the gas pipeline material, since they show the relationship between the structure, fracture toughness and deformation parameters of the material [14][15][16][17]. In our opinion, they can be an effective supplement to the non-destructive control methods.…”

“…The energy intensity of fracture depends not only on the size of the specimen fracture surface, but on the hardness of the stress-strain state of the material volumes in these areas [16]. Moreover, while at the macroscale level the deformed material undergoes shear deformation and detachment, and at the mesolevel -shear and turn, at the microlevel it undergoes shear, turn and local extension.…”

Evaluation of dynamic fracture toughness parameters of locomotive axle steel by instrumented Charpy impact test

“…However, the long‐term operation and the effect of corrosive media can lead to the formation of defects on the surface of wheelset axles . Therefore, the investigation of the material impact toughness, which allows assessing the material condition and its resistance to impact loading in the presence of stress concentrators, is important . In some papers, physically grounded evaluation parameters of strength and fracture toughness of materials are developed, which allow linking energy efficiency of failure to the physical mechanisms of deformation at different structural levels of the material.…”

Effects of Alloy Content on Impact Toughness in X80 Pipeline Steel

“…Besides, the project also under severe conditions of higher pressures and low temperatures, it can be abruptly fractured when cracks initiate and propagate rapidly by impact, explosion, or earthquake. Therefore, the performance of pipeline steel plate put forward higher requirements, especially for impact toughness [1][2][3].…”

“…Besides, the project also under severe conditions of higher pressures and low temperatures, it can be abruptly fractured when cracks initiate and propagate rapidly by impact, explosion, or earthquake. Therefore, the performance of pipeline steel plate put forward higher requirements, especially for impact toughness [1][2][3].Based of the advanced hot rolling mill, the company successfully developed and manufactured the X80 pipeline steel for the third-line project of west to east gas transmission project. In order to accord the high toughness requirements, the alloying elements Mo, Ni, Cu, Cr, Nb, V and Ti, et al have been employed, combining with TMCP process.…”