Investigation of fatigue and fracture characteristics for low-temperature metals considering the effects of various alloying components

Abstract

In the past few decades, low-temperature metals such as SUS304L, nickel alloys, and high-manganese steels have been widely used for liquefied natural gas (LNG) storage tanks to satisfy the structural integrity requirements at low temperature. Many researchers have conducted studies to characterize the fatigue and fracture performance of low-temperature metals. However, only a limited number of studies have considered the effects of various welding processes and consumables. This study addresses the fatigue and fracture performance of low-temperature metals while considering the effects of various alloying components. Moreover, we investigated the fatigue and fracture performance of various welding processes. Flux core arc welding (FCAW) was employed for both SUS304L and 9 wt.% nickel alloy steel, while tungsten inert gas (TIG) and shield metal arc welding (SMAW) were applied to SUS304L and 9 wt.% nickel alloy steel, respectively. Submerged arc welding (SAW) was employed for high-manganese steel. Fatigue and fracture tests were conducted according to ASTM E647 and BS 7448. The mechanical properties of the weld metals were systematically analyzed. SUS304L with FCAW exhibited excellent crack tip opening displacement (CTOD) and fatigue crack growth rate (FCGR). We also observed the microstructure of weld metals and discuss the mechanisms related to the fatigue and fracture performance in the parent and weld metals.