Corrosion behavior and fatigue of alloy 625, alloy 33 and alloy 31 under conditions of decouplers in automotive exhaust systems

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:352609

Agarwal, D C ^[1]; Kloewer, J; Koehler, M; Kolb-Telieps, A ^[2]

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

The alloys 625, 31, 33 and in some tests the newly developed alloy 626Si have been investigated with respect to their mechanical properties and their corrosion resistance against alkali salts containing chlorides at temperatures of 550 C, 65O C, 7OO C and 750 C. Concerning strength in the sensitized condition, all alloys are suitable as decoupler materials. The mechanical properties of alloys 625, 626Si and probably 31 indicate adequate manufacturing possibilities of bellows. All alloys investigated suffer accelerated corrosion in the presence of alkali salt containing chlorides at temperatures ranging from 550 C to 750 C. At 750 C alloy 626Si shows the lowest corrosion rate. At 75O C, 7OO C and 650 C no difference between the solution annealed and the sensitized specimens was found. At 55O C, however, the corrosion rate of the alloys 625 and 33 increased significantly, when the material was sensitized prior to corrosion testing. Alloy 31 does not suffer significant corrosion attack at 55O C both in the solution annealed and in the sensitized condition, thus making it a potential cost effective alternative to the more expensive alloy 625 for decoupler applications.

• OSTI ID: 352609
• Report Number(s): CONF-980316--
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
AUTOMOBILES
CORROSION RESISTANCE
CORROSION RESISTANT ALLOYS
EXHAUST SYSTEMS
INCONEL 625
IRON BASE ALLOYS
MECHANICAL PROPERTIES
NICKEL BASE ALLOYS
SODIUM CHLORIDES