Progress with alloy 33 (UNS R20033), a new corrosion resistant chromium-based austenitic material

Book · Fri Nov 01 04:00:00 EST 1996

OSTI ID:382596

Koehler, M; Heubner, U ^[1]; Eichenhofer, K W; Renner, M ^[2]

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1. Krupp VDM GmbH, Werdohl (Germany)
2. Bayer AG, Leverkusen (Germany)

Alloy 33 (UNS R20033), a new chromium-based corrosion resistant austenitic material with nominally (wt. %) 33 Cr, 32 Fe, 31 Ni, 1.6 Mo, 0.6 Cu, 0.4 N has been introduced to the market in 1995. This paper provides new data on this alloy with respect to mechanical properties, formability, weldability, sensitization characteristics and corrosion behavior. Mechanical properties of weldments including ductility have been established, and match well with those of wrought plate material, without any degradation of ISO V-notch impact toughness in the heat affected zone. When aged up to 8 hours between 600 C and 1,000 C the alloy is not sensitized when tested in boiling azeotropic nitric acid (Huey test). Under field test conditions alloy 33 shows excellent resistance to corrosion in flowing 96--98.5% H{sub 2}SO{sub 4} at 135 C--140 C and flowing 99.1% H{sub 2}SO{sub 4} at 150 C. Alloy 33 has also been tested with some success in 96% H{sub 2}SO{sub 4} with nitrosyl additions at 240 C. In nitric acid alloy 33 is corrosion resistant up to 85% HNO{sub 3} and 75 C or even more. Alloy 33 is also corrosion resistant in 1 mol. HCl at 40 C and in NaOH/NaOCl-solutions. In artificial seawater the pitting potential remains unchanged up to 75 C and is still well above the seawater`s redox potential at 95 C. Alloy 33 can be easily manufactured into all product forms required. The new data provided support the multipurpose character of alloy 33 to cope successfully with many requirements of the Chemical Process Industry, the Oil and Gas Industry and the Refinery Industry.

• OSTI ID: 382596
• Report Number(s): CONF-960389--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHARPY TEST
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
COPPER ADDITIONS
CORROSION RESISTANCE
CREVICE CORROSION
ELONGATION
EXPERIMENTAL DATA
GAS TUNGSTEN-ARC WELDING
IRON ALLOYS
LASER WELDING
MECHANICAL PROPERTIES
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NITRIC ACID
NITROGEN ADDITIONS
PITTING CORROSION
PLASMA ARC WELDING
SEAWATER
SHIELDED METAL-ARC WELDING
SODIUM HYDROXIDES
STRESS CORROSION
SULFURIC ACID
TENSILE PROPERTIES
WELDABILITY
WELDED JOINTS
YIELD STRENGTH