Effect of weld metal chemistry and heat input on the structure and properties of duplex stainless steel welds
15 Oct 2003-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing (Elsevier)-Vol. 358, Iss: 1, pp 9-16
TL;DR: In this article, a low heat input process viz., EBW and another commonly employed process, gas tungsten-arc welding have been employed for welding of duplex stainless steels with and without nickel enhancement.
Abstract: The excellent combination of strength and corrosion resistance in duplex stainless steels (DSS) is due to their strict composition control and microstructural balance. The ferrite–austenite ratio is often upset in DSS weld metals owing to the rapid cooling rates associated with welding. To achieve the desired ferrite–austenite balance and hence properties, either the weld metal composition and/or the heat input is controlled. In the current work, a low heat input process viz., EBW and another commonly employed process, gas tungsten-arc welding have been employed for welding of DSS with and without nickel enhancement. Results show that (i) chemical composition has got a greater influence on the ferrite–austenite ratio than the cooling rate, (ii) and even EBW which is considered an immature process in welding of DSS, can be employed provided means of filler addition could be devised.
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25 May 2011-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the laser welded ANSI 304 stainless steel joint was treated by laser shock processing (LSP) with different shocked paths, that is, single-sided LSP impacts and two-sided lSP impacts.
Abstract: The laser welded ANSI 304 stainless steel joint was treated by laser shock processing (LSP) with different shocked paths, that is, single-sided LSP impacts and two-sided LSP impacts. The tensile test of the tensile samples was carried out by MC electronic tensile testing machine, and the fractographes of the tensile samples were characterized by scanning electron microscope (SEM). Results showed that compared with single-sided LSP impacts, the mechanical properties (including the yield strength, the tensile strength, the elongation and the area reduction) of the laser welded ANSI 304 stainless steel was clearly improved by two-sided LSP impacts. Based on the analysis of the SEM observation, the ductility of the treated samples by two-sided LSP impacts was better than that by single-sided LSP impacts due to more and deeper elongated dimples in the fracture.
41 citations
TL;DR: In this article, the effect of microstructure on SCC susceptibility of DSS was examined in simulated white-liquor to see the impact of micro-structure properties on the susceptibility of steel to SCC.
Abstract: Duplex stainless steel (DSS) grades are used in pulp mills for their superior properties and resistance to general corrosion. However, stress corrosion cracking (SCC) of DSS equipment has been experienced in different pulp mills. The susceptibility of DSS grades to SCC can be mainly attributed to the various heating processes involved during the manufacturing of industrial equipments, especially welding. It is generally understood that heating cycles during welding may affect the dual microstructure (ferrite/austenite ratio) of the steel, making it more prone to cracking in aggressive environments such as chlorides and caustics and further exposure to high temperatures. Welded 2205 DSS failed in white liquor (mainly NaOH + Na2S) was examined for SCC crack morphology and microstructure. Heat-treated 2205 DSS samples were tested in simulated white liquor to see the effect of microstructure on SCC susceptibility. Austenite is more susceptible to SCC than ferrite, but the SCC susceptibility primarily depends on the composition of the alloy and the chemistry of the exposure environment.
40 citations
Cites background from "Effect of weld metal chemistry and ..."
...The dual microstructure provides unique properties such as high tensile and fatigue strength, good toughness and formability and excellent resistance to general corrosion and stress corrosion cracking (SCC) [1–3]....
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TL;DR: The ultrafine grained 2205 duplex stainless steel with an average grain size of 300nm was obtained by cold rolling down to 95% reduction in thickness and reversion annealing at 900°C for 200 s as mentioned in this paper.
39 citations
04 Feb 2019-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the microstructure dependence of impact toughness was studied for a 2205 duplex stainless steel in the temperature range of −196 to 25°C, where three markedly different austenite morphologies (i.e., rolled (R), equiaxed (E) and Widmanstatten (W)) were produced through different thermomechanical routes.
Abstract: In this study, the microstructure dependence of impact toughness was studied for a 2205 duplex stainless steel in the temperature range of −196 to 25 °C. Three markedly different austenite morphologies (i.e., rolled (R), equiaxed (E) and Widmanstatten (W)) were produced through different thermomechanical routes. It was found that while the room temperature impact toughness of all microstructures were quite similar, the microstructure dependence of impact toughness significantly increased with decreasing testing temperature. At cryogenic temperatures, microstructure R showed significantly higher toughness compared to microstructures E and W. Considering a 40 J criterion, the ductile to brittle transition temperature was estimated to be ∼ −80 °C for microstructures W and E, while microstructure R showed impact toughness values higher than 40 J even at −196 °C. The lamellar character of microstructure R and the termination of ferrite phase on the (100) plane orientation in this microstructure were found to have a positive effect on the toughness. The occurrence of deformation twinning within ferrite at low temperatures, facilitated by significantly coarser grain sizes in microstructures E and W compared to R, appeared to be the main reason behind the observed deterioration of the impact toughness of the former microstructures at these temperatures.
39 citations
TL;DR: In this article, the weldability of 6mm thick plates of super-duplex stainless steel by electron beam welding (EBW) process was investigated and tensile results corroborated that the joints obtained by EB welding process have better strength than the base metal.
39 citations
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01 Jan 1997
TL;DR: In this paper, the authors present a non-destructive testing of welds for service experience, based on the application of service experience in metallurgy and metallurgical applications.
Abstract: Developments, grades and specifications Alloy design Microstructure Forming and machining Physical and mechanical properties Corrosion Stress corrosion cracking Welding metallurgy Welding processes Weld properties Non-destructive testing of welds Applications Service experience.
449 citations