Microstructural characteristics and corrosion behavior of a super duplex stainless steel casting
- Industrial Manager of SULZER BRASIL S/A and Professor of the Sao Paulo Salesian University Center (UNISAL), Americana Division, SP (Brazil)
- Department of Materials, Aeronautical and Automotive Engineering, Sao Carlos School of Engineering, University of Sao Paulo (USP), Sao Carlos, SP Brazil (Brazil)
The machining of super duplex stainless steel castings is usually complicated by the difficulty involved in maintaining the dimensional tolerances required for given applications. Internal stresses originating from the solidification process and from subsequent heat treatments reach levels that exceed the material's yield strength, promoting plastic strain. Stress relief heat treatments at 520 deg. C for 2 h are an interesting option to solve this problem, but because these materials present a thermodynamically metastable condition, a few precautions should be taken. The main objective of this work was to demonstrate that, after solution annealing at 1130 deg. C and water quenching, stress relief at 520 deg. C for 2 h did not alter the duplex microstructure or impair the pitting corrosion resistance of ASTM A890/A890M Grade 6A steel. This finding was confirmed by microstructural characterization techniques, including light optical and scanning electron microscopy, and X-ray diffraction. Corrosion potential measurements in synthetic sea water containing 20,000 ppm of chloride ions were also conducted at three temperatures: 5 deg. C, 25 deg. C and 60 deg. C.
- OSTI ID:
- 21192599
- Journal Information:
- Materials Characterization, Vol. 60, Issue 2; Other Information: DOI: 10.1016/j.matchar.2008.12.010; PII: S1044-5803(08)00341-0; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
- Country of Publication:
- United States
- Language:
- English
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