Super duplex stainless steels

1992 ◽  
Vol 8 (8) ◽  
pp. 685-700 ◽  
Author(s):  
J.-O. Nilsson
Keyword(s):  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Super Duplex Stainless Steels

Hot Cracking Susceptibility in Duplex Stainless Steel Welds

2018 ◽  
Vol 941 ◽  
pp. 679-685
Author(s):  
Kazuyoshi Saida ◽  
Tomo Ogura
Keyword(s):  
Stainless Steels ◽  
Laser Beam Welding ◽  
Austenitic Stainless Steels ◽  
Hot Cracking ◽  
Duplex Stainless Steels ◽  
Solidification Cracking ◽  
Solidification Mode ◽  
Gas Tungsten Arc ◽  
Varestraint Test ◽  
Super Duplex Stainless Steels

The hot cracking (solidification cracking) susceptibility in the weld metals of duplex stainless steels were quantitatively evaluated by Transverse-Varestraint test with gas tungsten arc welding (GTAW) and laser beam welding (LBW). Three kinds of duplex stainless steels (lean, standard and super duplex stainless steels) were used for evaluation. The solidification brittle temperature ranges (BTR) of duplex stainless steels were 58K, 60K and 76K for standard, lean and super duplex stainless steels, respectively, and were comparable to those of austenitic stainless steels with FA solidification mode. The BTRs in LBW were 10-15K lower than those in GTAW for any steels. In order to clarify the governing factors of solidification cracking in duplex stainless steels, the solidification segregation behaviours of alloying and impurity elements were numerically analysed during GTAW and LBW. Although the harmful elements to solidification cracking such as P, S and C were segregated in the residual liquid phase in any joints, the solidification segregation of P, S and C in LBW was inhibited compared with GTAW due to the rapid cooling rate in LBW. It followed that the decreased solidification cracking susceptibility of duplex stainless steels in LBW would be mainly attributed to the suppression of solidification segregation of P, S and C.

Copper and its effects on microstructure and correlated tensile properties of super duplex stainless steels

2021 ◽  
pp. 141544
Author(s):  
G. Ressel ◽  
M. Gsellmann ◽  
D. Brandl ◽  
A. Landefeld ◽  
A. Keplinger ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Super Duplex Stainless Steels

scholarly journals Some pitfalls in welding of duplex stainless steels

2010 ◽  
Vol 15 (4) ◽  
pp. 336-343 ◽  
Author(s):  
Demian J. Kotecki
Keyword(s):  
Stainless Steels ◽  
Heat Input ◽  
Austenitic Stainless Steels ◽  
Duplex Stainless Steels ◽  
Austenite Formation ◽  
Track Record ◽  
Super Duplex Stainless Steels ◽  
Input Range ◽  
Secondary Austenite ◽  
Filler Metals

Duplex stainless steels (DSS, including super duplex stainless steels {SDSS}) have proven to be very useful engineering materials, albeit with somewhat different welding requirements than those of the more familiar austenitic stainless steels. Despite a generally good track record in welding of duplex stainless steels, certain pitfalls have been encountered with enough frequency that they deserve review. Inappropriate base metal specification often leads to unsuitable heat affected zone (HAZ) properties. Autogenous fusion zones are also of concern. This issue centers around nitrogen limits. The most frequently encountered is applying the UNS S31803 composition for 2205 DSS, instead of the S32205 composition. Inappropriate welding heat input arises most frequently with SDSS. While 0.5 to 1.5 kJ/mm is a normal heat input recommendation for SDSS, either a root pass or many small beads towards the low end of this heat input range tends to result in precipitation and/or secondary austenite formation in weld metal subjected to repeated thermal cycles from multiple weld passes. Inappropriate PWHT occurs when the enhanced nickel filler metals (typically 9% Ni) are used. DSS are not normally given PWHT, but extensive forming of heads, for example, or repair welding of castings, may require a postweld anneal. Specifications such as ASTM A790 and A890 call for annealing at 1040ºC minimum, and the fabricator tends to use temperatures close to that minimum. However, the enhanced nickel filler metals require higher temperatures to dissolve sigma phase that forms during heating to the annealing temperature.

scholarly journals Effect of Tantalum Addition on Pitting Corrosion Behavior of Super Duplex Stainless Steels

2015 ◽  
Vol 64 (7) ◽  
pp. 320-323 ◽  
Author(s):  
Makoto Kawamori ◽  
Junichiro Kinugasa ◽  
Yosuke Yonenaga ◽  
Yuko Fukuta ◽  
Masaki Shimamoto ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Super Duplex Stainless Steels

scholarly journals Difficulties in the Machining Super Duplex Stainless Steels

2019 ◽  
Vol 11 (1) ◽  
pp. 141-144
Author(s):  
András István Nagy ◽  
Enikő Réka Fábián ◽  
Richárd Horváth ◽  
Pal Terek
Keyword(s):  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Dry Turning ◽  
Significant Difference ◽  
Super Duplex Stainless Steels ◽  
Cutting Inserts

Abstract Super duplex stainless steels are used in increasingly more areas. The machinability of duplex stainless steels is generally poor. We performed dry turning tests on G X2CrNiMoCuN 26-6-3-3 casted superduplex steel, using two different PVD coated cutting inserts. One of them was coated with TiAlN and other with TiAlSiN. Strong burr and built-up edge formation were observed during our machining experiments; these damaged the edges of the tools. The shortened tests did not show significant difference betwen the effect of the coatings.

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