Fatigue performance of friction stir welded weathering mild steels joined below A1 temperature

Wang, Yixun; Tsutsumi, Sadami; Kawakubo, Takumi; Fujii, Hidetoshi

doi:10.1016/j.ijfatigue.2021.106667

Cited by 13 publications

(5 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…27 The strain distribution on the X-Y plane of the LFW specimen was measured using DIC during the monotonic testing, and the DIC equipment used in this research was the same as in previous studies. 10,17,18,26,28 The fatigue experiment was carried out on a total of 14 LFW specimens by a servo hydraulic testing machine at a loading rate of 16 Hz and stress ratio R = 0.1. The loading rate was decreased to 0.01 Hz every 1000 cycles so that the DIC could be used to measure the strain distribution on the Y-Z surface of the specimen.…”

Section: Methodsmentioning

confidence: 99%

“…The monotonic tensile experiment was conducted at a cross‐head speed of 0.1 mm/min according to JIS 27 . The strain distribution on the X‐Y plane of the LFW specimen was measured using DIC during the monotonic testing, and the DIC equipment used in this research was the same as in previous studies 10,17,18,26,28 . The fatigue experiment was carried out on a total of 14 LFW specimens by a servo hydraulic testing machine at a loading rate of 16 Hz and stress ratio R = 0.1.…”

Section: Methodsmentioning

confidence: 99%

“…The welded joints with no defects were obtained, and the embrittlement caused by a high phosphorus content was overcome. Based on these studies, Wang 17,18 conducted monotonic and fatigue tests on the FSW joined weathering steels. The welded joints illustrated a joint efficiency as high as 100%, and the fatigue strength of the welded joints was comparable to that of the base metal (BM).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fatigue strength and fracture characteristics of linear friction welded joints of weathering mild steel

Wang

Tsutsumi

Kawakubo

et al. 2022

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

Weathering steel with high phosphorus content usually cannot be joined by fusion welding due to the possible solidification crack. The present study successfully joined the unweldable weathering steel SPA‐H by linear friction welding (LFW) above the A3 temperature. The microstructure, microhardness, and residual stress were measured and analyzed. The stress concentration factor (SCF) of LFW joints was assessed by the finite element method (FEM). The influence of flash on the fatigue strength and fracture characteristics was investigated. The results suggest that the weld center zone (WCZ) consisting of ferrite and bainite shows a necking shape. The ductile fracture of LFW joints occurred at the base metal, resulting in a joint efficiency close to 100%. The possible unbonded flash at the edge of the LFW joints greatly reduced the fatigue life. The proposed S‐N curve illustrates a much higher fatigue strength than the FAT90 design curve.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fatigue strength and fracture characteristics of linear friction welded joints of weathering mild steel

Wang

Tsutsumi

Kawakubo

et al. 2022

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

show abstract

“…Similar limitations also exist in friction stir technologies, like microstructural transition zones and tool contact-based geometrical discontinuities or residual stresses. Consequently, limiting the endurance limit to 2 × 10 6 cycles may be acceptable [27,28].…”

Section: Fracture Surfacesmentioning

confidence: 99%

Fatigue and Impact Behavior of Friction Stir Processed Dual-Phase (DP600) Steel Sheets

Yilmaz,

Ozturk Yilmaz,

Saray

2024

Metals

View full text Add to dashboard Cite

This study investigates the impact of friction stir processing (FSP) on the deformation behavior of 1.1 mm-thick DP600 steel sheets under both static and dynamic loading scenarios, with a focus on the automotive applications of the material. During the process, the large plastic shear strains imposed by FSP resulted in a maximum temperature of 915 °C, leading to a morphological transformation of the martensite phase from well-dispersed fine particles into lath martensite and grain refinement of the ferrite phase. DP600 steel showed an almost two-fold increase in static strength parameters such as the hardness value, yield strength, and ultimate tensile strength. As-received and processed DP600 steel exhibited a plastic deformation behavior governed by strain hardening. However, uniform elongation and elongation to failure after FSP took lower values compared to those of the as-received counterpart. Following the improvement in the static strength of the steel, the fatigue strength of the steel increased from 360 MPa to 440 MPa after the FSP. The finite-life fatigue fracture surfaces of the as-received samples were characterized by the formation of fine bulges due to the variation in the crack propagation path in the vicinity of the martensite particles/clusters. After FSP, the transformation of the martensite particles into coarser lath martensite also transformed the fracture surface into a step-like morphology. The microstructural evolution after FSP caused a decrease in the absorbed impact energy and maximum striker reaction force from 239 J and 37.6 kN down to 183 J and 33.6 kN, respectively. However, the energy absorption capacity of the processed steel up to failure was higher than the absorbed energy value of the as-received steel at the same impact displacement. The simultaneous decrease in both impact energy and reaction force is attributed to the higher cracking tendency of the processed microstructure due to the lower volume fraction of the ferrite phase. The experimental results reported in this study mainly show that FSP is an easy-to-apply and functional solution to significantly improve the static and cyclic strength of DP600 steel. However, it is clear that the reduced total impact energy absorption capacity after FSP may be taken into account in design strategies.

show abstract

“…Currently, the DIC method has been widely used in the measurement of full-field strain in the FSW joints during static tension testing and has achieved good results. In the fatigue, the correlation between the inhomogeneous microstructure of the FSW joint and selective strain localization in fatigue has been investigated in some previous studies (Deng et al, 2017;Infante et al, 2016;Besel et al, 2019;Wang et al, 2022;He et al, 2015). It was reported that the difference of the microstructure generally leads to the selective strain localization in the weld, which is closely associated with the fatigue crack initiation location and results in the final fracture of the specimen.…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous deformation of friction stir welded aluminum alloy 6061 in tension and high cycle fatigue

DAI

Liu

Zhan

et al. 2022

IJSI

View full text Add to dashboard Cite

PurposeThe investigations provide a basis for the optimization of the alloy 6061-T6 friction stir welding (FSW) process to improve the mechanical properties of welded joints.Design/methodology/approachThe local deformation of the FSW joint in tension and fatigue test were experimentally investigated by digital image correlation (DIC) technique.FindingsThe local stress-strain behaviors of the sub-regions show that the plastic strain always concentrated at the heat affected zone (HAZ) on the advancing side both in tension and high cycle fatigue and eventually leads to the final fracture. The evolution of the plastic strain at very low stress is extremely slow and accounts for most of the total fatigue life. However, the local deformation exhibits a sudden increase just before the fatigue failure.Originality/valueBased on the experimental data, the result indicates that the HAZ is the weakest zone across the weld and the strain localization in high cycle fatigue is very harmful and unpredictable for the FSW joints.

show abstract

Fatigue performance of friction stir welded weathering mild steels joined below A1 temperature

Cited by 13 publications

References 34 publications

Fatigue strength and fracture characteristics of linear friction welded joints of weathering mild steel

Fatigue strength and fracture characteristics of linear friction welded joints of weathering mild steel

Fatigue and Impact Behavior of Friction Stir Processed Dual-Phase (DP600) Steel Sheets

Heterogeneous deformation of friction stir welded aluminum alloy 6061 in tension and high cycle fatigue

Contact Info

Product

Resources

About