Mechanical properties of butt weldments made with E5515-G electrodes at high temperature: Fid-Bau Portal

Mechanical properties of butt weldments made with E5515-G electrodes at high temperature

Guo, Zhen / Qiao, Wenjuan / Jia, Xingzhi

Abstract The current design standards provide strict recommendations to ensure the quality of welds. In this study, the mechanical properties of welds subjected to elevated temperatures are investigated by performing steady-state tensile tests and transient-state tests on butt weldments composed of Q420B base metal and E5515G electrodes. Comparison of the results reveals that the welding heat-affected zone (HAZ) is vulnerable to fracture when subjected to reheating above 500 °C. it is more reasonable to use the results of the transient-state tests than those of the steady-state tests to deduce the reduction factors for the mechanical properties of weldments subjected to a temperature of 200 °C and higher. The physical stress fields and thermally induced stress fields are affected not only by the quantity of superposition but also by the time series. At 500 °C and higher, the butt welds are considered unsafe relative to the recommendation of the current design standards for the reduction factors of the yield strengths. Finally, it is still risky to use the recommendations of the current design standards directly to predict the mechanical properties of butt welds at a high temperature, particularly in the range of 500 °C to 800 °C.

Highlights • We conduct the tensile tests on butt welds at elevated temperature. • We provide the reduction factors of but welds in fire. • Current design standards are not suit for butt welds in fire. • It should use the results from the transient-state tests to deduce the reduction factors.