Heterogeneities in local plastic flow behavior in a dissimilar weld between low-alloy steel and stainless steel

Mas, Fanny; Martin, Guilhem; Lhuissier, Pierre; Bréchet, Y.; Tassin, C.; Roch, François; Todeschini, Patrick; Simar, Aude

doi:10.1016/j.msea.2016.04.082

Cited by 21 publications

(13 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In welds between a ferritic and an austenitic steel, the combination of the local chemical composition and the rapid cooling subsequent to welding creates a narrow band of martensite along the fusion line [15,20,28] that greatly influences carbon migration and microstructural evolutions during post-weld heat treatment [29][30][31] with a significant effect on the mechanical properties of the joint [10,32]. Another characteristic feature of ferritic/austenitic welds is the occurrence of Type-II grain boundaries on the weld metal side, next to the fusion line and almost parallel to it, that have been prone to premature cracking under stress [18] or hydrogen-rich environments [4].…”

Section: Introductionmentioning

confidence: 99%

Growth Morphologies and Primary Solidification Modes in a Dissimilar Weld between a Low-Alloy Steel and an Austenitic Stainless Steel

Mas

Tassin

Roch

et al. 2018

Metals

Self Cite

View full text Add to dashboard Cite

Dissimilar welds close to the fusion boundary exhibit a variety of solidification microstructures that strongly impact their service behavior. Investigations were therefore undertaken to clarify the origins of the morphological and microstructural evolutions encountered in a 18MND5/309L dissimilar joint produced by submerged arc welding, using a combination of microstructural characterizations, thermodynamic computations, and solidification modelling. An unexpected evolution was observed in the solidification mode, from primary austenite towards primary ferrite with increasing growth rate. Solidification of austenite at the fusion boundary was assigned to its epitaxial growth on the metastable austenitic structure of the base metal resulting from an incipient melting mechanism. The evolution of the solidification mode toward primary ferrite was explained based on computations of the solute built up between austenite cells followed using the so-called "interface response function model". Analyzing macro-and microstructural characteristic lengths with the published solidification model and data enabled evaluation of local values of the solidification rate, thermal gradient, and cooling rate close to the fusion boundary, thus providing useful data for numerical modelling of the submerged arc-welding process.

show abstract

Section: Introductionmentioning

confidence: 99%

Growth Morphologies and Primary Solidification Modes in a Dissimilar Weld between a Low-Alloy Steel and an Austenitic Stainless Steel

Mas

Tassin

Roch

et al. 2018

Metals

Self Cite

View full text Add to dashboard Cite

show abstract

“…Mas [1,20] a étudié l'influence des transformations de phase subies par la LBM inox pendant le soudage et le TTD sur ses propriétés mécaniques en identifiant une loi constitutive élasto-plastique isotrope pour chaque couche de la soudure à température ambiante. Plusieurs techniques expérimentales ont été utilisées à cet effet.…”

Section: Bibliographie Sur Le Comportement Mécanique Des Lbm Inoxunclassified

Brittle Fracture of Stainless Steel Dissimilar Metal Welds in the Upper Shelf of the Brittle-to-Ductile Transition Range

Salem¹,

Chapuliot²,

Blouin³

et al. 2020

Volume 6: Materials and Fabrication

View full text Add to dashboard Cite

Stainless steel dissimilar metal welds (SS DMW) are widely used within the French nuclear power plants where they connect the main components (pressure vessel, pressurizer, steam generator) made of low alloy ferritic steel to the primary circuit pipes made of austenitic stainless steel. Because of their heterogeneous microstructure and mechanical properties, these junctions are critical components for the structure integrity and their fracture resistance has to be demonstrated for all the nominal or accidental operating conditions. This work aims at building a model to evaluate the risk of brittle fracture of the SS DMW in the upper shelf of the brittle-to ductile transition range. The observation of the microstructures around the fusion line revealed a martensitic layer and a fully austenitic zone, which undergo an important carbides precipitation during the post-weld heat treatment and form a narrow hard layer of carburized martensite and austenite. Fracture toughness tests were then carried out on CT specimens in the brittle-to-ductile temperature range and helped identify the MA interface (between martensite and austenite) as the weakest region in the SS DMW because of an intergranular fracture mechanism initiated at the carbides-rich interface. This mechanism was consistently observed for specimens with fatigue precrack fronts in the hard layer. To model the brittle behavior of the MA interface, the stress distributions on the MA interface were calculated with FE numerical simulation of the fracture toughness tests and a 1D 3 parameters Weibull model based on a threshold stress and a threshold length was identified for the CT specimens. The temperature dependence of the model parameters was finally studied and the effect of temperature on the intergranular fracture mechanism of the MA interface was explored.

show abstract

“…Thus, several researches have been pursued to improve DWJ performance. One is to remove welding defects by the evaluation of welding parameters like current and gas flow [8]; the other is improve metallurgical behavior of DWJ by cooling rate and Post Weld Heat Treatment [9][10]. Despite these proposals, DWJ between HSLA and ASS constitutes a major challenge of researchers [7], especially for solving metallurgical problems of fusion zone (FZ) and heat affected zone (HAZ).…”

Section: Introductionmentioning

confidence: 99%

“…Despite these proposals, DWJ between HSLA and ASS constitutes a major challenge of researchers [7], especially for solving metallurgical problems of fusion zone (FZ) and heat affected zone (HAZ). These problems are concentrated around the fusion line, due to coarsening of microstructures, hardening precipitates and the formation of brittle phases during welding process [9][10]. In view of welding process application, thermal welding cycles provokes the diffusion of some alloying elements like C, Fe, Cr and Ni [10][11].…”

Section: Introductionmentioning

confidence: 99%

“…These problems are concentrated around the fusion line, due to coarsening of microstructures, hardening precipitates and the formation of brittle phases during welding process [9][10]. In view of welding process application, thermal welding cycles provokes the diffusion of some alloying elements like C, Fe, Cr and Ni [10][11]. Hence, carbide precipitations are found mainly in weld interfaces due to higher carbon content of HSLA than that of ASS [11].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study of the influence of wire metals on dissimilar welds

Benlamnouar

Bensaid

Badji

et al. 2022

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

The aim of this study is to investigate the effect wire metal on microstructure and mechanical properties of dissimilar welds between HSLA-X70 high strength steel alloy and 304L austenitic stainless steel produced by automatic tungsten arc welding (TIG). The weld joints were prepared using E304L, E316L, E2209L, and E7010 wire metal. The mechanical characteristics obtained from hardness, tensile and impact testing, were correlated to the optical and SEM microscopy, to establish a relationship between wire metal composition and the microstructures in different weld regions. It is concluded that E2209 wire metal lead to improve in the resilience characteristics and tenacity with a slight reduction in the ultimate tensile strength and hardness.

show abstract

Heterogeneities in local plastic flow behavior in a dissimilar weld between low-alloy steel and stainless steel

Cited by 21 publications

References 25 publications

Growth Morphologies and Primary Solidification Modes in a Dissimilar Weld between a Low-Alloy Steel and an Austenitic Stainless Steel

Growth Morphologies and Primary Solidification Modes in a Dissimilar Weld between a Low-Alloy Steel and an Austenitic Stainless Steel

Brittle Fracture of Stainless Steel Dissimilar Metal Welds in the Upper Shelf of the Brittle-to-Ductile Transition Range

Study of the influence of wire metals on dissimilar welds

Contact Info

Product

Resources

About