Effect of Cryogenic Temperature on Low-Cycle Fatigue Behavior of AISI 304L Welded Joint

Dongjin Oh,Namkyu Kim,Myunghyun Kim,Sangwoo Song

doi:10.3390/met8090657

Dongjin Oh, Namkyu Kim + Show 2 more

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https://doi.org/10.3390/met8090657

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Abstract

The aim of this study is to investigate the low-cycle fatigue (LCF) properties of an AISI 304L welded joint based on experimental data. The influential parameters on the LCF such as the specimen thickness, strain ratio and cryogenic temperature were considered in this experimental study. In order to investigate the thickness effect on the LCF behavior, two types of specimens with thicknesses of 5 mm and 10 mm were used in an LCF test. In addition, the fatigue tests were conducted under strain control with three different strain ratios of R = −1, 0, and 0.5 at room and cryogenic temperatures. Based on the results obtained by this experimental study, no significant effect involved with the thickness and the strain ratio were observed. However, it was clearly observed that LCF performance at room temperature is lower than that at cryogenic temperature. Finally, an LCF design curve that can be used in design of the liquefied natural gas (LNG) applications is suggested.

Highlights

Austenitic stainless steel is one of most important structural materials used in various engineering fields owing to its excellent strength, toughness, and sufficient corrosion resistance [1,2].Among austenitic stainless steels, AISI 304L is commonly employed to manufacture liquefied natural gas (LNG) cargo tanks because of its higher performance in a cryogenic environment
Based on the results obtained by this experimental study, no significant effect involved with the thickness and the strain ratio were observed
It was clearly observed that low-cycle fatigue (LCF) performance at room temperature is lower than that at cryogenic temperature

Summary

Introduction

AISI 304L is commonly employed to manufacture liquefied natural gas (LNG) cargo tanks because of its higher performance in a cryogenic environment. This material exhibits a special characteristic called secondary hardening owing to stress- or strain-induced phase transformation [3,4]. This state, called the martensitic transformation, leads to hardening behavior during low-cycle fatigue. The cryogenic temperature that is required to liquefy the natural gas affects the mechanical properties as well as the fatigue strength of LNG carriers

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