Influence of Oxygen Content on the Inclusion Formation and Pitting Corrosion Resistance of Hyper Duplex Stainless Steels

Jeon, Soon-Hyeok; Hur, Do Haeng; Kim, Hye Jin; Park, Yong Soo

doi:10.2320/matertrans.m2014164

Cited by 17 publications

(11 citation statements)

References 23 publications

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“…Another challenge in AM is minimizing the occurrence of defects such as porosity, cracking, and lack of fusion, as defects will deteriorate the mechanical properties [ 35 ]. Another factor is the component chemical composition, particularly oxygen and nitrogen contents, since oxygen affects the ductility and toughness, and nitrogen influences phase balance and therefore properties [ 49 , 50 ]. The most important factor is the microstructure, governing properties, which was investigated in the present study as presented in this and earlier papers [ 3 , 4 ].…”

Section: Discussionmentioning

confidence: 99%

Wire Laser Metal Deposition Additive Manufacturing of Duplex Stainless Steel Components—Development of a Systematic Methodology

et al. 2021

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A systematic four-stage methodology was developed and applied to the Laser Metal Deposition with Wire (LMDw) of a duplex stainless steel (DSS) cylinder > 20 kg. In the four stages, single-bead passes, a single-bead wall, a block, and finally a cylinder were produced. This stepwise approach allowed the development of LMDw process parameters and control systems while the volume of deposited material and the geometrical complexity of components increased. The as-deposited microstructure was inhomogeneous and repetitive, consisting of highly ferritic regions with nitrides and regions with high fractions of austenite. However, there were no cracks or lack of fusion defects; there were only some small pores, and strength and toughness were comparable to those of the corresponding steel grade. A heat treatment for 1 h at 1100 °C was performed to homogenize the microstructure, remove nitrides, and balance the ferrite and austenite fractions compensating for nitrogen loss occurring during LMDw. The heat treatment increased toughness and ductility and decreased strength, but these still matched steel properties. It was concluded that implementing a systematic methodology with a stepwise increase in the deposited volume and geometrical complexity is a cost-effective way of developing additive manufacturing procedures for the production of significantly sized metallic components.

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Section: Discussionmentioning

confidence: 99%

Wire Laser Metal Deposition Additive Manufacturing of Duplex Stainless Steel Components—Development of a Systematic Methodology

et al. 2021

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“…Equations (1)–(3) consider only the elements that have a positive effect on the resistance to pitting corrosion, but they do not consider the harmful impurities of sulfur and oxygen [ 6 ], which form non-metallic inclusions (NMIs) that reduce the corrosion resistance of steels [ 20 , 21 , 22 , 23 ]. The distribution, quantity, size, and composition of NMIs depend on the technology of steel melting and deoxidation [ 24 ], and affect the corrosion resistance [ 25 ]. For example, pitting often occurs at the interface between inclusions and the metal matrix [ 25 , 26 ].…”

Section: Introductionmentioning

confidence: 99%

“…The distribution, quantity, size, and composition of NMIs depend on the technology of steel melting and deoxidation [ 24 ], and affect the corrosion resistance [ 25 ]. For example, pitting often occurs at the interface between inclusions and the metal matrix [ 25 , 26 ]. However, at present there is no unequivocal opinion on the contribution of certain NMIs to the formation of corrosion resistance [ 23 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

“…For example, pitting often occurs at the interface between inclusions and the metal matrix [ 25 , 26 ]. However, at present there is no unequivocal opinion on the contribution of certain NMIs to the formation of corrosion resistance [ 23 , 25 ]. Complex inclusions containing aluminum, magnesium, calcium, and silicon oxides, as well as spinel-like NMIs containing chromium, manganese, iron, and aluminum, are the most harmful NMIs [ 25 ].…”

Section: Introductionmentioning

confidence: 99%

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Development of a Methodology for the Quality Management of Duplex Stainless Steels

et al. 2022

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The use of traditional materials leads to failures and breakdowns of expensive equipment, so advanced materials are needed that can provide reliable and durable solutions. The ability to control the quality of duplex stainless steels (DSSs) can greatly help with the development of new compositions or choosing existing DSSs. In this case, it is necessary to consider the final consumer properties—corrosion resistance and mechanical properties, which depend on the phase composition, contamination with non-metallic inclusions (NMIs), and the presence of undesirable secondary phases. In this research, specimens of cast DSSs of different grades, produced at laboratory and industrial scales, were studied. A technique for quantifying the microstructure of DSSs was developed. A thermodynamic database was chosen that adequately describes the processes of phase formation in DSSs. The effects of heat treatment on the microstructure and corrosion properties of cast DSSs were studied. The effects of the structural state on the changes in consumer properties of the final product are shown. It is shown that using various deoxidation technologies, it is possible to obtain both NMIs that are dangerous in terms of corrosive activity and ones that are relatively safe.

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“…Another aspect that was specifically investigated in this work was if oxygen pick-up could be a concern in LMDw of duplex stainless steels. It is well-known that oxygen content is detrimental for pitting corrosion resistance due to the formation of oxide inclusions that act as pit initiation sites [30] and for mechanical properties, especially for impact toughness [31] in duplex stainless steel weldments.…”

Section: Introductionmentioning

confidence: 99%

Microstructure of laser metal deposited duplex stainless steel: Influence of shielding gas and heat treatment

et al. 2020

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This research work is the first step in evaluating the feasibility of producing industrial components by using Laser Metal Deposition with duplex stainless steel Wire (LMDw). The influence of Ar and N2 shielding gases was investigated in terms of nitrogen loss and in the microstructure and austenite content of different deposited geometries. The evolution of the microstructure in the build-up direction of the Ar and N2-shielded blocks was compared in the heat-treated and as-deposited conditions. The susceptibility for oxygen pick-up in the LMDw deposits was also analyzed, and oxygen was found to be in the range of conventional gas-shielded weldments. Nitrogen loss occurred when Ar-shielding was used; however, the use of N2-shielding prevented nitrogen loss. Austenite content was nearly doubled by using N2-shielding instead of Ar-shielding. The heat treatment resulted in an increase of the austenite content and of the homogeneity in the microstructure regardless of the shielding gas used. The similarity in microstructure and the low spread in the phase balance for the as-deposited geometries is a sign of having achieved a stable and consistent LMDw process in order to proceed with the build-up of more complex geometries closer to industrial full-size components.

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Influence of Oxygen Content on the Inclusion Formation and Pitting Corrosion Resistance of Hyper Duplex Stainless Steels

Cited by 17 publications

References 23 publications

Wire Laser Metal Deposition Additive Manufacturing of Duplex Stainless Steel Components—Development of a Systematic Methodology

Wire Laser Metal Deposition Additive Manufacturing of Duplex Stainless Steel Components—Development of a Systematic Methodology

Development of a Methodology for the Quality Management of Duplex Stainless Steels

Microstructure of laser metal deposited duplex stainless steel: Influence of shielding gas and heat treatment

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