Alloy 33, a new material resisting marine corrosion

Book · Mon Dec 01 00:00:00 EST 1997

OSTI ID:549894

Agarwal, D C ^[1]; Koehler, M ^[2]

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1. VDM Technologies Corp., Houston, TX (United States)
2. Krupp VDM GmbH, Werdohl (Germany)

A new austenitic chromium-based material alloyed with nominally (wt.%) 33 Cr, 32 Fe, 31 Ni, 1.6 Mo, 0.6 Cu and 0.4 N, having a pitting resistance equivalent of 50, has been developed recently. The alloy exhibits excellent local corrosion resistance in chloride-bearing media. When tested in 10% FeCl{sub 3} {center_dot} 6 H{sub 2}O solution, a critical pitting temperature of 85 C was determined. Low segregation in the matching weld metal means that the critical pitting temperature of a 5 mm PAW weld seam is only 10 C lower. Potentiostatic corrosion tests in artificial seawater at 0.3 V (SCE) with additions of 0.5 mol NaCl reveal no pitting corrosion at 85 C, and crevice corrosion in artificial seawater at 0.3 V (SCE) has not been observed at temperatures below 55 C. In saturated CaCl{sub 2} solutions at 125 C under constant load conditions the resistance to stress corrosion cracking of Alloy 33 is superior even to that of Alloy 926. The combination of excellent corrosion resistance to a broad variety of media with high yield strength, 30% above that of the nitrogen-alloyed 6% Mo stainless steels, not only offers a cost-effective alternative to higher-cost nickel alloys, but also allows for light weight structures in the Offshore Industry. Alloy 33 (UNS R20033) has been approved by ASME and VdTUEV for pressure vessels in the temperature range of {minus}196 C to 450 C and can be manufactured to all semi-finished products used in the marine and chemical industries.

• OSTI ID: 549894
• Report Number(s): CONF-970332-; TRN: IM9752%%117
• Resource Relation: Conference: Corrosion 97. 52. annual corrosion conference of the National Association of Corrosion Engineers: economics and performance - bridging the gap and NACExpo, New Orleans, LA (United States), 9-14 Mar 1997; Other Information: PBD: 1997; Related Information: Is Part Of Corrosion/97 conference papers; PB: [4584] p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES
CORROSION RESISTANT ALLOYS
SEAWATER
MECHANICAL PROPERTIES
CHROMIUM ALLOYS
NICKEL ALLOYS
IRON ALLOYS
MOLYBDENUM ALLOYS
COPPER ADDITIONS
NITROGEN ADDITIONS
CORROSION RESISTANCE
PITTING CORROSION
CREVICE CORROSION
STRESS CORROSION
CRACK PROPAGATION
YIELD STRENGTH
OFFSHORE PLATFORMS
PRESSURE VESSELS
NUMERICAL DATA