RECENT DEVELOPMENTS OF ADVANCED AUSTENITIC …

super austenitic stainless steels with high Mo, Ni, Cr and N contents [3], super duplex stainless steels [4] and the recently developed hyper duplex stainless steels [5]. This paper will provide an overview on the development, properties and applications of these advanced materials for oil & gas and process industry.

Comparative study of mechanical, corrosion and erosion

Duplex stainless steels (DSSs) used in subsea structures and desalination industries require high corrosion and erosion resistance as well as excellent mechanical properties. The newly introduced cast duplex grade ASTM A890 7A has a unique composition and is expected to have a much better resistance to corrosion and erosion …

UNS S32707 hyper-duplex stainless steel processed by …

UNS S32707 hyper-duplex stainless steel (HDSS) was prepared by powder injection molding (PIM) and supersolidus liquid-phase sintering from powder prepared by a plasma rotating-electrode process, and the nitrogen content and relative density of the sintered parts were 0.37% and 97.9%, respectively. The densification and nitrogen …

Detection of Secondary Phases in UNS S32760 Superduplex Stainless …

Duplex stainless steels (DSS), with a microstructure of an approximately equal mixture of ferrite (α) and austenite (γ) phases, are susceptible to the formation of undesirable phases if manufacturing processes are not carefully controlled. In particular, sigma phase (σ) is a Cr- and Mo-rich intermetallic phase, formed generally when DSS …

SAF™ 2707 HD hyper-duplex stainless steel — Alleima

SAF™ 2707 HD is a hyper-duplex stainless steel; a high-alloy duplex steel with a PRE value of min. 48*. The grade is characterized by excellent chloride corrosion resistance, …

CORRELATION BETWEEN MICROSTRUCTURAL AND …

In this work was investigated the duplex stainless steel modified by boron by spray-forming, in order to characterize the using different techniques, optical microscopy, SEM-FEG, X-ray diffraction, Rama spectroscopy and hardness (VH) and Thermo-Calc software, with goal of determining the corrosion resistance. The corrosion resistance test …

Mixed potential model for passivity characters of hyper-duplex

Hyper‐duplex stainless steel (HDSS) 2707 is a competitive material for application in extremely caustic environments. In this study, different annealing temperatures ranging from 1020°C to 1200 ...

SAF™ 3207 HD — Alleima

SAF™ 3207 HD is a hyper-duplex (austenitic-ferritic) stainless steel for service in highly corrosive conditions where also high mechanical strength is necessary. …

Effect of Boron Distribution on the Intergranular

[1] Kajimura H., Ogawa K. and Nagano H. 1991 Effect of α/γ phase ratio and N addition on the corrosion resistance of Si-bearing duplex stainless steel in nitric acid ISIJ Intl. 31 216 Crossref Google Scholar [2] Pardo A., Otero E. and Hernaez J. 1991 Influence of microstructure on the intergranular corrosion resistance of 24.4Cr/7.4Ni duplex …

Point defect model for passivity breakdown on hyper-duplex stainless

However, the available information on pitting mechanisms of the duplex stainless steels, especially the hyper-duplex stainless steel is still very rare. In this paper, the PDM is employed to investigate the pitting predictions as a function of temperature, Br-concentration, pH and potential scan rate, and gives the pitting parameters of HDSS 2707.

Metals | Free Full-Text | Characterization of the …

This study investigates the microstructure, mechanical properties, and corrosion resistance of a friction-stir-welded joint of the hyper duplex stainless steel SAF2707. Friction stir welding (FSW) is performed at a tool rotation rate of 400 rpm and a welding speed of 100 mm/min. The microstructure of the joints is examined using …

Subsea tubes in duplex and super-duplex steel — Alleima

Alleima's range of subsea tubes includes steels of ASTM 316L type, SAF™ 2205 duplex stainless steel and SAF 2507 super-duplex stainless steel. New material for subsea …

Early Stages of Deleterious Phases in Super and Hyper Duplex Stainless

Duplex stainless steels combine excellent mechanical properties with good corrosion resistance. Consequently, they are in frequent use in various highly demanding applications, like Oil & Gas, chemical processing, pulp and paper, and desalination plants. Due to their high alloying contents, super and hyper duplex are susceptible to the …

Microstructure and Corrosion Studies on Different Zones of Super Duplex

The influences of microstructure and elemental distribution on pitting corrosion resistance and passive film in different regions of a super duplex stainless steel welded joint were investigated. The banded microstructure disappeared after welding and transformed to the coarse equiaxed ferrite grains in the heat-affected zone. Three types of austenitic …

(PDF) Influence of multiple welding cycles on microstructure …

Super duplex stainless steels, defined as duplex stainless steels w ith a PREN – value (PREN = % Cr +3.3% Mo + 16%N) exceeding 40, present exc ellent corrosion resistance and superior strength.

Duplex stainless steel — Alleima

SAF™ 3207 HD hyper-duplex stainless steel. SAF™ 3207 HD is a hyper-duplex stainless steel with a PRE value of min. 50* for service in highly corrosive conditions where also very high mechanical strength is required. This makes the grade ideal for use in deep-water umbilicals and a range of other oil and gas applications. Read more about SAF ...

INTRODUCTION TO DUPLEX STAINLESS STEELS

Penn Stainless Products, Inc • 190 Kelly Road • Quakertown, Pennsylvania 18951 USA P PS S P P Toll Free: 1-800-222-6144 • Phone: 215-536-3053 • Fax: 215-536-3255 • E-mail: [email protected] CHEMICAL COMPOSITION The duplex stainless steels are loosely divided into categories depending on the level of alloying or …

Investigation of the sensitization and intergranular corrosion …

Hyper duplex stainless steels (HDSSs) are defined as highly alloyed DSSs with a pitting resistance equivalent number (PREN = wt.% Cr + 3.3 (wt.% Mo + 0.5 wt.% W) + 16 wt.% N) of 45–50 [2]. The corrosion resistance of DSSs is determined by the proper fractions of α and γ-phases and by the Cr-depleted zone adjacent to secondary phases …

Effect of Austenite Reformation on Localized Corrosion

The materiality of duplex stainless steels for deep-sea applications, where high corrosive conditions prevail, was studied in the present work. The effect of annealing temperature on the phase balance of the new hyper-duplex grade and subsequent variation in their corrosion resistance at hot chloride environments were estimated. ASTM A890 …

Sandvik duplex stainless steels

Sandvik SAF 2707 HD is a hyper-duplex steel that is designed to resist corrosion in the most severe chloride containing environments. Sandvik SAF 2707 HD can also serve as …

Hyper Duplex Stainless Steels and Their Weldability

Hyper duplex stainless steels (HDSS), which are the most advanced products of the duplex stainless steel class, containing ferrite and austenite phases in high densities, still have a very niche ...

Investigation of the sensitization and intergranular corrosion of …

The effects of thermal aging of hyper-duplex stainless steel (HDSS) 2707 at 900℃ for various aging times up to 26 h on the localized, selective corrosion were investigated by electrochemical methods. The results demonstrate that the optimum test condition is 2 M H 2 SO 4 + 1.25 M HCl + 0 0.001 M KSCN with the scan rate of 1.5 …

Effect of nitrogen protection on weld metal microstructure …

Duplex stainless steel (DSS) is one of the preferred structural materials for nuclear power plants. Compared with other stainless steels, DSS has the advantages of high strength and good corrosion resistance. ... al. Influence of the shielding gas composition on the passive film and erosion corrosion of tube-to-tube sheet welds of …

Scienceirect ScienceDirect

In order to meet these challenges, hyper duplex stainless steels have recently been developed. These materials have nitrogen contents up to about 0.5% and PRE-values close to 50, and show both highest

Effects of W substitution on the precipitation of

In this study, to elucidate the effects of W substitution on the precipitation of secondary phases and associated pitting corrosion in hyper duplex stainless steels, potentiodynamic anodic polarization test, a scanning electron microscope–energy dispersive spectroscope (SEM–EDS) analysis, thermodynamic calculation using Thermo-Calc …

Analysis of Sigma Formation Mechanisms in Aged Hyper Duplex Stainless …

In this study, the evolution of sigma-phase development in a 2205 duplex steel was studied following thermal ageing in the temperature range 750-850 A degrees C for periods up to 100 h.

Experimental investigation on dry sliding wear

ASTM A890 grade 7A is the newest addition to the family of duplex stainless steels with a unique composition having small amount of rare earth elements. This work is aimed at comparing the sliding wear behaviour of commercially used 5A, 6A and recently developed 7A grades of duplex stainless steel at high sliding velocities.

Studies on the degree of sensitization of hyper-duplex stainless …

The effects of thermal aging of hyper-duplex stainless steel (HDSS) 2707 at 900℃ for various aging times up to 26 h on the localized, selective corrosion were investigated by electrochemical methods. The results demonstrate that the optimum test condition is 2 M H 2 SO 4 + 1.25 M HCl + 0 0.001 M KSCN with the scan rate of 1.5 …

Predictive computations of intermetallic σ phase evolution in duplex

1. Introduction. In duplex stainless steels (DSS), there is an ideal 1:1 ratio of α-ferrite and γ-austenite which ensures the outstanding mechanical and corrosion resistance of the materials [1].Processing of these steels is a challenging task due to complex precipitation and phase transformations during heat treatment [2].Intermetallic phases …

Welding guidelines for duplex, super duplex and hyper duplex stainless

Abstract and Figures. When welding duplex and super-duplex steels, the biggest challenge is to maintain an optimized balance between the austenite- ferrite microstructure in the final weld metal ...

Microstructures and element distributions in an aged hyper duplex

The microstructures and the distribution of alloying elements in alloy and intermetallic phases forming in a hyper-duplex stainless steel during aging at temperatures in the range of 750°C–1050°C are characterized by Electron probe micro analysis. Due to long aging times of up to 48 h, close-to-equilibrium configurations are obtained over ...

Duplex stainless steel — Alleima

Microstructure and Corrosion Studies on Different Zones of Super Duplex

of tube-to-tube sheet welds of hyper duplex stainless steel in acidified chloride. environments. Corros. Sci. 64, 164–173. doi: 10.1016/j.corsci.2012.07.014. Leif, (2012). Welding duplex ...

Super Austenitic vs. Duplex/Super/Hyper Duplex Stainless …

Super Austenitic vs. Duplex/Super/Hyper Duplex Stainless Steels Super Austenitic vs. Duplex/Super/Hyper Duplex Stainless Steels FOM1 (Mechanical) (OP) 8 Feb 22 12:34. I'm searching for the most definitive guide & reference for corrosion resistance factors, such as PREN, CCCT & CPT for the super austenitic (254/64SMO, 904L & …