Analysis of low transformation temperature welding (LTTW) consumables – distortion control and evolution of stresses

Thomas, Siby; Liu, S.

doi:10.1179/1362171814y.0000000199

“…In the present work martensitic transformation which formed in 3rd pass was used to produce compressive stresses on 2nd pass, hence tensile stresses were reduced and cracks were prevented. Because of elastic modulus increase with decreasing of metal temperature; the amount of compressive stresses generated from martensitic transformation increased with decreasing of TMs [13,14].…”

Section: Effect Of Tms Value On Type II Grain Boundary Conditionsmentioning

confidence: 99%

Prevent Cracking in Deposition of Carbon Steel on Inconel 625

Morsy

¹

,

Koussy

²

,

Farag

³

2019

MATEC Web Conf.

0

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Welding procedure of clad steel including deposition of carbon steel on nickel base alloy usually gives unaccepted mechanical properties. Cracks were formed along type II boundary in nickel base alloy pass and a martensitic layer was formed in carbon steel pass. In this paper, cracks along type II boundary were prevented by lowering the martensitic start temperature (TMs) of the martensitic layer. Decreasing of TMs was obtained by two methods: Dilution method and Grain refining method. Three levels of TMs (approximately 350, 200, and 50⁰C) are obtained. The results showed that: cracks along type II boundary were prevented at TMs lower than 200⁰C; however type II boundary itself was prevented at TMs lower than 50𠜌. Also post weld heat treatment was necessary to achieve accepted impact properties.

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“…In the present work martensitic transformation which formed in 3 rd pass was used to produce compressive stresses on 2 nd pass, hence tensile stresses were reduced and cracks were prevented. Because of elastic modulus increase with decreasing of metal temperature; the amount of compressive stresses generated from martensitic transformation increased with decreasing of TMs [13,14]. Because of quantitative measurements of stresses at type II grain boundary are hard to conduct, a qualitative method was used to give an indication about stress level.…”

Section: Effect Of Tms Value On Type II Grain Boundary Conditionsmentioning

confidence: 99%

“…U sadašnjem radu korišćena je martenzitna transformacija nastala u 3. prolazu da bi se proizvele pritisna naprezanja na 2. prolazu, pa su smanjeni zatezni naponi i sprečene su prsline. Zbog toga što se modul elastičnosti povećava sa smanjenjem temperature metala; količina pritisnih napona stvorena martenzitnom transformacijom, povećana je sa smanjenjem T Ms [13,14] Zato što je kvantitativno merenje naprezanja na granici zrna tipa II teško sprovesti, upotrebljena je kvalitativna metoda da se dobije indikacija o nivou napona. Ova tehnika je nastavljena posmatranjem bilo kakvih prslina u blizini granice stapanja, tj.…”

Section: Effect Of Tms Value On Type II Grain Boundary Conditionsunclassified

Prevent cracking in deposition of Carbon steel on Inconel 625

Farag¹,

Morsy²,

El³

2019

Zavariv zavar konstrukcije

0

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Welding procedure of clad steel including deposition of carbon steel on nickel base alloy usually gives unaccepted mechanical properties. Cracks were formed along type II boundary in nickel base alloy pass and a martensitic layer was formed in carbon steel pass. In this paper, cracks along type II boundary were prevented by lowering the martensitic start temperature (TMs) of the martensitic layer. Decreasing of TMs was obtained by two methods: Dilution method and Grain refining method. Three levels of TMs (approximately 350, 200, and 50 o C) are obtained. The results showed that: cracks along type II boundary were prevented at TMs lower than 200 o C; however type II boundary itself was prevented at TMs lower than 50 o C. Also post weld heat treatment was necessary to achieve accepted impact properties. Rezime Tehnologija zavarivanja platiranog čelika, uključujući nanošenje ugljeničnog čelika na leguru nikla, obično daje neprihvatljiva mehanička svojstva. Prsline su formirane duž granice tipa II u prolazu od legure nikla i formiran je martenzitni sloj u prolazu od ugljeničnog čelika. U ovom radu, prsline duž granice tipa II su sprečene smanjenjem martenzit start temperature (T Ms) martenzitnog sloja. Smanjenje T Ms je postignuto na dva načina: metodom razblaživanja i metodom rafinacije zrna. Dobijena su tri nivoa T Ms (približno 350, 200 i 50°C). Rezultati su pokazali da su: prsline duž granice tipa II bile sprečene kod T Ms nižih od 200 o C; međutim, sama granica tipa II bila je sprečena kod TM niže od 50 o C. Takođe je bila potrebna toplotna obrada nakon zavarivanja da bi se postigle prihvatljive karakteristike udarnih osobina.

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“…There have been rising interests in the development of LTTW filler alloys for various applications in the past two decades (Refs. [9][10][11][12][13][14][15][16]. In these reported studies, the LTTW consumables contained up to 15…”

Section: Introductionmentioning

confidence: 99%

Control of Weld Residual Stress in a Thin Steel Plate through Low Transformation Temperature Welding Consumables

Wu¹,

WANG²,

Yu³

et al. 2020

WJ

5

0

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Low transformation temperature welding (LTTW) consumables are characterized by a low martensite start temperature and a large fraction of martensite forming in the weld. It can efficiently reduce the tensile residual stress because the volume expansion associated with the martensitic transformation compensates for the thermal contraction during cooling. In this work, a LTTW wire, designated as EH200B, was created for the arc welding of advanced high-strength steel thin plates. In comparison to conventional ER70S-3 wires, this LTTW wire generated an opposite distortion pattern. Neutron diffraction measurements along the center thickness of the welded plates showed the maximum residual stress along the longitudinal direction (LD) in the weld region, and the heat-affected zone (HAZ) immediately adjacent to the weld region was reduced from ~330 MPa to below 240 MPa by using the LTTW wire. A finite element (FE) model was developed to predict the residual stress distributions of the plates welded under these two wires. The simulation results showed reasonable agreement with the volume-average neutron diffraction data. Compressive residual stress in the weld region using the LTTW wire was predicted by the FE method. Electron backscattered diffraction and x-ray diffraction measurements confirmed ~90% martensite was present in the LTTW weld. The fatigue life of DP980 steel lap joint panels using EH200B wire nearly doubled that of ER70S-3 wire. This improvement was attributed to the high strength and low LD residual stress in the weld and HAZ immediately adjacent to the weld.

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Analysis of low transformation temperature welding (LTTW) consumables – distortion control and evolution of stresses

Cited by 26 publications

References 18 publications

Prevent Cracking in Deposition of Carbon Steel on Inconel 625

Prevent Cracking in Deposition of Carbon Steel on Inconel 625

Prevent cracking in deposition of Carbon steel on Inconel 625

Control of Weld Residual Stress in a Thin Steel Plate through Low Transformation Temperature Welding Consumables

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