Solidification behavior of austenitic stainless steel filler metals

David, S. A.; Goodwin, G.M.; Braski, D.N.

doi:10.2172/5563513

Cited by 21 publications

(24 citation statements)

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“…in stainless steels, the solidification path near the Fe-rich corner of the ternary system has been extensively studied by many researchers. 6,[8][9][10][11][12][13][14][15] Except for a relatively low Cr and Ni region where a peritectic reaction (Lϩd→g) takes place, a wide compositional range of FeCr-Ni alloys solidify in a eutectic manner (L→dϩg), 8,10,12) with a primary phase formed from the liquid first being d…”

Section: Introductionmentioning

confidence: 99%

The Effect of Alloy Solidification Path on Sulfide Formation in Fe–Cr–Ni Alloys

et al. 2009

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Solidification and sulfide precipitation in Fe-Cr-Ni alloys were investigated. Five samples containing 0.3 wt% S and 1.5 wt% Mn were investigated and each sample chemistry was adjusted to solidify as primary austenite, primary ferrite or eutectic by tailoring the Cr and Ni contents. 355© 2009 ISIJ or g, depending on the balance between Cr and Ni contents. In the 70wt%Fe-Cr-Ni system, if Ni content is less than 10-12 wt%, the alloy will encounter the d-liquidus first and begin to form d phase when it is cooled down from the liquid state, while if Ni content exceeds 10-12 wt% it will solidify as g phase first after passing the g-liquidus during cooling. 8,10,16) At this stage of solidification, the partition of Fe, Cr and Ni between the liquid and the primary solid phase is dependent on the slope of liquidus surface; i.e., the primary solid phase is rich in Fe and the remained liquid is rich in Cr and Ni. 6,8,15) In the region where Ni content lies between 10-12 wt%, the remaining liquid undergoes a eutectic reaction at the latter stage of solidification where the three phases coexist. When the liquid composition reaches a eutectic valley, partitions of solute elements in d and g phases will occur through eutectic reaction; i.e., d phase is rich in Cr and g phase rich in Ni. In summary, as a result of a specific solidification path along which an alloy undergoes, significant partitioning of alloying elements take place. 6,8,9,11,[13][14][15]17,18) Numerous papers have been published on morphology and characterization of sulfides in steel. Among sulfides, manganese sulfide (MnS) is commonly observed and utilized in steel, especially in free machining grades, and extensive studies have been devoted to understanding the formation of MnS.19-25) When S content is small (e.g., less than 1 wt%), MnS will form either in a monotectic or a eutectic manner during solidification, depending on the amounts of other alloying elements such as C, Si and Al. 20,22) Although these elements are not constituents of sulfides, they can switch the formation process of MnS from monotectic to eutectic reaction by lowering melting temperature of the metal matrix or supplying nucleation sites for MnS, which results in the change in morphology of sulfides. 20,22) Besides this change in sulfide morphology potentially caused by these elements, solidification structures, d, g, or the mixture of d and g, can influence the sulfide morphology as well as distribution and composition because partitions of S and sulfide forming elements vary from phase to phase which has a specific solubility limit of sulfide. Since sulfide morphology, distribution and composition have a critical effect on hot crack susceptibility, it is necessary to have a basic understanding of how sulfides precipitate in different solidification modes.Several researchers carried out in-situ observation of sulfide formation using a confocal scanning laser microscope (CSLM). 26,27) In Si-killed and Al-killed steels, MnS was seen to form rapidly as a film on the surface of the interd...

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Section: Introductionmentioning

confidence: 99%

The Effect of Alloy Solidification Path on Sulfide Formation in Fe–Cr–Ni Alloys

et al. 2009

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“…Los AIA presentan cuatro modos de solidificación que han sido estudiados desde la década del 80 principalmente por David et al [15,16], Lippold y Savage [17] y Olson [18] por lo que es posible establecer una relación entre la cantidad y morfología de la ferrita δ y las propiedades mecánicas y de resistencia a la corrosión de las uniones. Los modos de solidificación se dividen en tipo A donde la transformación es completamente austenítica, tipo AF donde la transformación se da inicialmente como austenita y posteriormente se inicia la transformación ferrítica obteniendo una estructura de ferrita δ interdendrítica, el tipo FA en el cual la solidificación inicia como ferrita δ y posteriormente la austenita consume a la ferrita δ por medio de una reacción de difusión limitada.…”

Section: Transformaciones Microestructurales En Soldaduras Disímiles unclassified

“…Este tipo es el más común para los AIA y produce morfologías de ferrita δ vermicular o en listones. Finalmente está el tipo F caracterizado por una solidificación completa como ferrita δ y una posterior transformación ferrita δ -austenita en estado sólido, éste modo de solidificación es característico de los aceros inoxidables dúplex y presenta morfologías de ferrita δ acicular, globular o placas de austenita Widmanstätten [1,11,14,15,19]. Se han realizado uniones disímiles de AIA con AIF mediante soldadura por fricción [20,21] y soldadura por láser [22], estos procesos involucran cambios microestructurales diferentes a los de soldadura por arco eléctrico.…”

Section: Transformaciones Microestructurales En Soldaduras Disímiles unclassified

“…La solidificación se da completamente como ferrita, el inicio de la transformación ferrita-austenita ocurre en los límites de grano ferrítico, posterior a eso se nuclea la austenita en el límite de grano y se forman placas de austenita Widmanstätten, como ha sido referenciado, esta transformación no es masiva sino que obedece a una transformación difusiva [1,17]. Debe notarse que los granos de ferrita formados inicialmente en la ZFD con CA son de mayor tamaño que los formados en la ZFD con CB [1,15,17,19].…”

Section: Transformaciones Microestructurales En Soldaduras Disímiles unclassified

“…Los métodos predictivos como los diagramas de Schaeffler y WRC-92 no toman en cuenta las velocidades de enfriamiento que son un factor determinante en la cantidad de ferrita δ presente en los depósitos de soldadura [15][16][17][18][19]28,31,32,[34][35][36][37], además, el diagrama de Schaeffler no tiene en cuenta el contenido de Nitrógeno en su cálculo del Níquel equivalente, que para el electrodo dúplex es de 0,2%. La técnica de permeabilidad magnética (Ferritoscopio Fischer) presenta algunas limitaciones prácticas relacionadas con las dimensiones de la muestra, por ejemplo, al usar muestras de tamaño reducido pueden disminuir los valores de ferrita δ medidos debido al efecto de borde.…”

Section: Resistencia a La Tensión Dureza Y Cantidad De Ferrita Delta δunclassified

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Transformaciones Microestructurales en Soldaduras Disímiles de Acero Inoxidable Austenítico con Acero Inoxidable Ferrítico

2015

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Este es un artículo publicado en acceso (Open Access) abierto bajo la licencia Creative Commons Attribution NonCommercial, que permite su uso, distribución y reproducción en cualquier medio, sin restricciones siempre que sin fines comerciales y que el trabajo original sea debidamente citado.Recibido: 25 Set., 2014 Aprobado: 16 Mar., 2015 E-mail: sara.aguilar@udea.edu.co (SMAS)Resumen: En este trabajo se estudian los fenómenos metalúrgicos que ocurren en la soldadura SMAW de un acero inoxidable ferrítico AISI 430 con un acero inoxidable austenítico AISI 316L. Para el estudio se utilizaron dos tipos de electrodos: austenítico AWS E309L y dúplex AWS E2209-16, ambos con un diámetro de 3,2 mm. Las uniones soldadas se realizaron con un solo pase y se variaron simultáneamente la corriente y la velocidad de soldadura; las condiciones fueron 49 A y 2,4 mm.s -1 como valores bajos y 107 A y 4,3 mm.s -1 como valores altos. Se evaluó la influencia del tipo de electrodo y de los parámetros de soldadura en la evolución microestructural de las zonas afectadas por el calor y de las zonas de fusión, encontrando diferencias en la morfología y cantidad de ferrita delta para todas las condiciones estudiadas. Se evidenció crecimiento y refinación de grano ferrítico y formación de martensita en la zona afectada por el calor del metal base ferrítico. Se evaluó también la resistencia a la tensión hallando similitudes en todas las soldaduras.Palabras-clave: Soldadura de aceros inoxidables; SMAW; Metalurgia de la soldadura; Acero inoxidable austenítico; Acero inoxidable ferrítico. Microstructural Transformations in Dissimilar Welds between Austenitic Stainless Steel and Ferritic Stainless SteelAbstract: This research studies the metallurgical transformations taking place the SMAW welding of AISI 316L austenitic stainless steel with AISI 430 ferritic stainless steel. To perform the study were used two different electrodes, AWS E309L austenitic and AWS E2209-16 duplex stainless steels 3.2 mm diameter. The joints were made with a single-pass welding including current and welding speed variations; the low values were 49 A and 2,4 mm.s -1 and the high values were 107 A and 4,3 mm.s -1 . This study evaluated the influence of the type of electrode and the welding parameters on the microstructural evolution of heat affected and fusion zones. Also, differences were found on morphology and delta ferrite amount for all weld metals. The heat affected zone of the ferritic side showed grain coarsening and grain refinement with martensite at the grain boundaries. Tensile strength was similar for all welded joints. Key-words:Stainless steel welding; SMAW; Welding metallurgy; Austenitic stainless steel; Ferritic stainless steel. IntroducciónLos aceros inoxidables (AI) son ampliamente usados en aplicaciones a elevadas temperaturas cuando los aceros al carbono y los aceros de baja aleación no presentan una adecuada resistencia a la corrosión. Los aceros inoxidables austeníticos (AIA) tienen mejor resistencia a la corrosión que los aceros inoxidables ferríti...

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Weld Solidification Cracking in 304 to 304L Stainless Steel

Hochanadel¹,

Lienert²,

Martinez³

et al. 2011

Hot Cracking Phenomena in Welds III

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IntroductionThe fact that austenitic stainless steels may be susceptible to weld solidification cracking is not new. In fact, correlations between cracking susceptibility and both the primary solidification mode (PSM) and the impurity content of these alloys have been made for a number of years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. These investigations have shown that with sufficient specific impurities and primary solidification of austenite, the weld metal is susceptible to weld solidification cracking.In addition, constitution diagrams, such as the Schaeffler Diagram and the Welding Research Council (WRC) diagrams have been used to select filler metals and/or predict resulting weld metal constituents in stainless steel welds [16][17][18][19]. These constitution diagrams and weld cracking susceptibility diagrams are specific to welding conditions, such as cooling rate. Many investigators have shown that the primary solidification mode changes with changes in solidification rate [20][21][22][23]. It is still convenient, however, to refer to weldability diagrams as the arc welding or pulsed laser beam welding (LBW) weldability diagram, without considering potential variations in solidification within each category. Little work, however, has been done in documenting weld cracking susceptibility in "similar alloy", dissimilar heat austenitic stainless steel welds [23][24]. Hochanadel, et al.,[24] have shown that weldability diagrams may be used to analyze the weldability of two "similar" dissimilar materials by noting the composition end-points and utilizing a tie-line between the two points. In changing an existing process from pulsed LBW to pulsed GTAW, the weldability is typically expected to be improved in that the "no cracking" region of the weldability diagram is expanded in the GTAW case. This work was done to investigate the weldability response of welding two dissimilar austenitic stainless steel heats together and comparing the response when welding with both a pulsed LBW and pulsed GTAW.

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Solidification behavior of austenitic stainless steel filler metals

Cited by 21 publications

References 3 publications

The Effect of Alloy Solidification Path on Sulfide Formation in Fe–Cr–Ni Alloys

The Effect of Alloy Solidification Path on Sulfide Formation in Fe–Cr–Ni Alloys

Transformaciones Microestructurales en Soldaduras Disímiles de Acero Inoxidable Austenítico con Acero Inoxidable Ferrítico

Weld Solidification Cracking in 304 to 304L Stainless Steel

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