Study of low-temperature effect on the fracture locus of a 420-MPa structural steel with the edge tracing method

• Published in: Fatigue & Fracture of Engineering Materials & Structures
• Main Authors: Tu, Shengwen, Ren, Xiaobo, Kristensen, Tore Andre, He, Jianying, Zhang, Zhiliang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Arctic
• Online Access: http://hdl.handle.net/11250/2577677; https://doi.org/10.1111/ffe.12803

Quasi-static tensile tests with smooth round bar and axisymmetric notched tensile specimens have been performed to study the low-temperature effect on the fracture locus of a 420-MPa structural steel. Combined with a digital high-speed camera and a 2-plane mirror system, specimen deformation was recorded in 2 orthogonal planes. Pictures taken were then analysed with the edge tracing method to calculate the minimum cross-section diameter reduction of the necked/notched specimen. Obvious temperature effect was observed on the load-strain curves for smooth and notched specimens. Both the strength and strain hardening characterized by the strain at maximum load increase with temperature decrease down to −60°C. Somewhat unexpected, the fracture strains (ductility) of both smooth and notched specimens at temperatures down to −60°C do not deteriorate, compared with those at room temperature. Combined with numerical analyses, it shows that the effect of low temperatures (down to −60°C) on fracture locus is insignificant. These findings shed new light on material selection for Arctic operation. submittedVersion This is the pre-peer reviewed version of an article, which has been published in final form at [https://doi.org/10.1111/ffe.12803]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.