High-Temperature Cycle Deformation and Fracture Behavior of Advanced Austenitic Heat-Resistant Steel Sanicro25 Alloy for A-USC Power Plants

Lyu, Dechao; Cao, Tieshan; Zhou, Tongtong; Cheng, Chuan; Zhao, Jie

doi:10.1007/s11661-022-06628-y

Cited by 9 publications

(6 citation statements)

References 47 publications

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“…Furthermore, the distribution of higher geometrically necessary dislocation (GND) densities is examined adjacent to grain boundaries and Z phase/matrix interfaces (Figure 11C). During high‐temperature deformation, dislocation gliding/climbing movement assisted by thermal activation can be hindered to accumulate at grain boundaries and primary Z phase 8,29 . The weaker binding force of the phase interfaces (the primary Z phase and the M 23 C 6 at grain boundary 7 ) provides the priority site for creep void initiation 11 .…”

Section: Discussionmentioning

confidence: 99%

“…During high-temperature deformation, dislocation gliding/climbing movement assisted by thermal activation can be hindered to accumulate at grain boundaries and primary Z phase. 8,29 The weaker binding force of the phase interfaces (the primary Z phase and the M 23 C 6 at grain boundary 7 ) provides the priority site for creep void initiation. 11 With further strain accumulation, the increased stress concentration causes creep voids to coarsen and develops into microcracks at the grain boundaries and primary Z phase.…”

Section: Crack Initiation Mechanismmentioning

confidence: 99%

“…Under high-temperature cyclic loading, the strain accumulation of materials can be achieved through dislocation climbing motion with the assistance of thermal activation. 29 Dislocations move and gradually accumulate to the primary Z phase and grain boundaries during the strain progresses. The initiation and coarsening of voids were found at grain boundaries and the primary Z phase interface at different stress amplitudes as the strain entered the accelerated regime.…”

Section: Effect Of Cyclic Stress Amplitude On Damage Evolutionmentioning

confidence: 99%

“…Our research group has researched the high-temperature cyclic deformation mechanism and life prediction analysis for Sanicro 25 alloy. 29 The current study is focused on the damage evolution characteristics (cracking initiation and propagation) related to mechanical response for Sanicro 25 alloy under high-temperature cyclic loading.…”

Section: Introductionmentioning

confidence: 99%

“…Understanding the effect of stress amplitude on creep‐dominated deformation and damage characteristics is essential for predicting fracture life and safety in service for a candidate material working in the steam environment at high temperatures and pressure. Our research group has researched the high‐temperature cyclic deformation mechanism and life prediction analysis for Sanicro 25 alloy 29 . The current study is focused on the damage evolution characteristics (cracking initiation and propagation) related to mechanical response for Sanicro 25 alloy under high‐temperature cyclic loading.…”

Section: Introductionmentioning

confidence: 99%

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Effect of stress amplitude on damage and fracture characteristics of austenitic heat‐resistant steel Sanicro 25 at 973 K

Lyu

Cao

Cheng

et al. 2023

Fatigue Fract Eng Mat Struct

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High‐temperature damage characteristics related to the deformation behavior of Sanicro 25 alloy were investigated under stress‐controlled cyclic loading. The results show that the strain curves exhibited creep‐like strain characteristics. The increase in mean stress increased the strain rate and weakened the life. Comparatively, the increase in stress amplitude only accelerated the tertiary‐regime strain rate, leading to a decrease in life and fracture strain. Microcrack initiation at grain boundaries and primary Z phases at different stress amplitudes can be evidenced by the observation of micro‐voids and high geometrically necessary dislocation densities around them. Subsequently, the increase in stress amplitude can significantly affect crack propagation. Dislocation accumulation at the transgranular crack tip caused by cyclic stress can assist the propagation of the transgranular crack at higher stress amplitude (). Conversely, transgranular cracks are easily suppressed and stop propagating at grain boundaries under constant loading (). The main reason was that the stress concentration of the transgranular crack tip at grain boundaries was dissipated through discontinuous dynamic recrystallization.

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Section: Discussionmentioning

confidence: 99%