Cryogenic stability of retained austenite in Fe–Cr–Ni weld metals obtained by laser welding

Xin, Dongqun; Lu, Shun; Cai, Yan; Hua, Xueming

doi:10.1007/s10853-021-06150-3

Cited by 2 publications

(2 citation statements)

References 33 publications

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“…In the weld metal specimens, the notch was positioned at the center of the welds (figure 2(a)). The CTOD tests were conducted at −120 °C [3,4]. When conducting a −120 °C low-temperature CTOD test, a specialized environmental chamber is used to control the temperature.…”

Section: Methodsmentioning

confidence: 99%

“…304L austenite stainless steel is usually used as pipes, valves or support plates that directly connect to the tank. Recently, autogenous laser welding between SA645 and 304L stainless steel has received great attention [3,4]. However, low-temperature properties such as cryogenic toughness and ductility of the weld is generally weak because of full martensite structure of the fusion zone.…”

Section: Introductionmentioning

confidence: 99%

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Effect of microstructure heterogeneity on the cryogenic fracture toughness of the dissimilar joint between SA645 and 304L made by laser welding

Zhou,

Wu,

et al. 2023

Mater. Res. Express

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The cryogenic fracture toughness of the SA645/304L dissimilar weld, produced using continuous wave IPG fiber laser welding with a 0.3 mm beam offset towards the 304L side, and the microstructural effects on the fracture behavior were systematically investigated. The weld metal consists of ∼89% columnar dendritic martensite and ∼11% retained austenite (RA), where the ununiform distribution of constituent phases as well as the distinctions between martensite and RA in terms of morphology and mechanical properties lead to the microstructure heterogeneity of weld metal. Pop-in phenomenon appears on the Force-Displacement (F-V) curve during the crack tip opening displacement (CTOD) test for the weld. The CTOD value for the weld is ∼0.057 mm, about 8 times less than that when pop-in effect is ignored (∼0.563 mm). Rapid propagation of the pre-fatigue crack tip along the center of the weld leads to the pop-in phenomenon. Fracture surface in pre-fatigue crack tip (PCT) region shows quasi-cleavage features, while fracture surface in stable crack propagation (SCP) region presents a ductile-fractured surface with dimples. The crack propagation path in SCP region is frequently deflected. Inhibition effect of grain boundaries on crack propagation and TRIP effect of retained austenite (RA) result in the improvement in fracture toughness of the SCP region.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%