Analysis of microstructural variation and mechanical behaviors in submerged arc welded joint of high strength low carbon bainitic steel

Lan, Liangyun; Qiu, Chunlin; Zhao, Dewen; Gao, Xiuhua; Du, Linxiu

doi:10.1016/j.msea.2012.08.057

Cited by 73 publications

(29 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The peak temperature and the cooling rate are the most important factors in determining the microstructural evolution within each subzone of the welded joint [20,21]. The characteristics of the microstructures within each of the different sub-zones (SCHAZ, ICHAZ, FGHAZ, CGHAZ and FZ) of the laser welded joint were examined using an SEM and micrographs are presented in Fig.…”

Section: Microstructurementioning

confidence: 99%

“…During the laser welding process, if the peak temperature increases to a value between the Ac 1 and Ac 3 temperatures, some austenite grains will nucleate on the tempered martensite and lower bainite packets or grain boundaries [21,33,34]. During this partial transformation, the austenite becomes enriched in C and then, owing to the fast cooling rates associated with the laser welding process, this newly generated austenite transforms to high C martensite, which can increase the hardness and lower the toughness of this region [32,35].…”

Section: Microstructure Characteristics In Different Sub-zonesmentioning

confidence: 99%

See 1 more Smart Citation

Microstructure and mechanical properties of laser welded S960 high strength steel

et al. 2015

View full text Add to dashboard Cite

Section: Microstructurementioning

confidence: 99%

Section: Microstructure Characteristics In Different Sub-zonesmentioning

confidence: 99%

Microstructure and mechanical properties of laser welded S960 high strength steel

et al. 2015

View full text Add to dashboard Cite

“…19) The isolated martensite contained a small amount of remained austenite between laths. 19) Therefore, martensitic islands are frequently referred to as martensite-austenite constituents (MA). Detailed studies of upper bainite and martensite were conducted by EBSD analysis.…”

Section: Crystallographic Characteristics Of Bainite/mar-mentioning

confidence: 99%

Micro-tensile Behaviour of Low-alloy Steel with Bainite/martensite Microstructure

et al. 2016

View full text Add to dashboard Cite

Micro-tensile testing and numerical analysis using a crystal plasticity finite element method (CPFEM) were employed to elucidate the deformation behaviour of bainite/martensite structures of a low-alloy steel. The bainite single-phase specimens exhibited habit-plane-orientation-dependent yielding, similar to the martensite single-phase specimens. In the bainite/martensite dual-phase specimen, deformation concentrated in the bainite region oriented favourably for in-habit-plane slip, leading to low-ductility fracture. With consideration of the habit-plane-orientation-dependent yielding, the present CPFEM analysis successfully reproduced the anisotropic plastic deformation behaviour of the single-phase steels observed in the experiments. The numerical results for the bainite/martensite specimen showed slip localization in the bainite region and stress concentration near the interphase boundary. This suggests that the interphase boundary can be a site for the fracture origin.KEY WORDS: micromechanical characterisation; bainite; martensite-austenite constituent; crystal plasticity finite element analysis; plastic anisotropy; habit plane.tensitic phases hinders the understanding of the mechanical response of each phase.Mine et al. have analysed the mechanical characteristics of the microconstituents in the single-phase lath martensite structure of a low-alloy steel using micro-tensile testing.12) This study revealed that lath martensite structures with single packets exhibited moderate ductility and that the plastic deformation behaviour depended on the habitplane orientation relative to the loading direction. Thus, micro-tensile testing allows for the analysis of deformation behaviour on the microstructural scale. In addition, a microtensile test study by Ogata et al. indicated that pre-strained ferrite/martensite dual-phase steel was embrittled by ultra grain refinement in the ferrite region, rather than by cracking in the martensite region.13) This finding suggested that martensite was not always the main cause of embrittlement in high-strength steels. In the present study, microtensile testing was employed to characterise the mechanical response of each phase in a bainite/martensite structure. Additionally, numerical analysis with crystal plasticity finite element method (CPFEM) was performed to elucidate the microscopic mechanism of the experimentally observed deformation behaviour.The CPFEM analyses have helped in understanding plastic behaviours, 14,15) and studies on dual-phase steels successfully reproduced the observed deformation and fracture behaviours. 16,17) However, few studies have applied CPFEM to bainite/martensite dual-phase-structured steel. Therefore, in the present study, we confirm the applicability of a simple CPFEM with linear hardening laws to the deforma- ISIJ International, Vol. 56 (2016), No. 12tion behaviour of the bainite and martensite single-phase structures. Furthermore, by using the material parameters identified in the analyses of single-phase structures, the analysis of the bainit...

show abstract

“…The M-A constituents can exhibit various morphologies such as massive, slender, and small dot cleavage cracking [12,13]. The M-A constituents can exhibit various morphologies such as massive, slender, and small dot shapes [14,15]. Specifically, the M-A constituents with small dot as well as dispersed and distributed shapes to not significantly contribute to the decrease in toughness [16].…”

Section: Introductionmentioning

confidence: 99%

Effect of Martensite–Austenite Constituent on Low-Temperature Toughness in YS 500 MPa Grade Steel Welds

Kim

Nam

Lee

et al. 2018

Metals

View full text Add to dashboard Cite

Abstract:The effect of martensite-austenite (M-A) constituents and simulated microstructure on low-temperature toughness was investigated in YS 500 MPa grade structural steel welds. The specimens were fabricated using a direct quenching and tempering process. After simulated weld thermal cycles, the coarse-grained heat-affected zone (CGHAZ) and intercritically reheated coarse-grained heat-affected zone (IRCGHAZ) were produced using a Gleeble tester and real welded joint to support the simulation results. The largest low-temperature toughness was observed in the fine-grained heat-affected zone (FGHAZ) owing to the fine-ferrite microstructure. However, the toughness decreased in the IRCGHAZ because of the slender morphology of the M-A constituents that formed primarily along the prior austenite grain boundaries in the IRCGHAZ.

show abstract

Analysis of microstructural variation and mechanical behaviors in submerged arc welded joint of high strength low carbon bainitic steel

Cited by 73 publications

References 34 publications

Microstructure and mechanical properties of laser welded S960 high strength steel

Microstructure and mechanical properties of laser welded S960 high strength steel

Micro-tensile Behaviour of Low-alloy Steel with Bainite/martensite Microstructure

Effect of Martensite–Austenite Constituent on Low-Temperature Toughness in YS 500 MPa Grade Steel Welds

Contact Info

Product

Resources

About