0
RESEARCH PAPERS

High Temperature Oxidation of Cr-Mo Steels in the Context of Accelerated Rupture Testing for Creep Life Prediction

[+] Author and Article Information
A. Al-Mazrouee, R. K. Singh Raman

Department of Mechanical Engineering, Monash University, Melbourne, Australia

J. Pressure Vessel Technol 129(3), 454-459 (Sep 21, 2006) (6 pages) doi:10.1115/1.2748826 History: Received August 26, 2005; Revised September 21, 2006

Accelerated creep rupture testing is used to aid in assessing the remaining life for components such as pipes and tubes used in high temperature plants. At the high temperatures, oxide growth can affect the creep results by diameter reduction and, thus, increase the stress. This paper includes the study of oxide-scale growth and diameter reduction kinetics during air oxidation of two Cr-Mo steels used in the manufacture of boiler tubing. Tests were at 500700°C for times up to 1000h for 1.25Cr-0.5Mo and 2.25Cr-1Mo steels (using cylindrical specimens similar to those used for creep testing). At 500600°C, 2.25Cr-1Mo steels showed a superior oxidation resistance than 1.25Cr-0.5Mo steels. However, at 700°C, the oxidation resistance of 1.25Cr-0.5Mo and 2.25Cr-1Mo steels was similar. Multilayer oxide formation was observed to occur in 1.25Cr-0.5Mo and 2.25Cr-1Mo steels, involving oxides with various compositions. It is suggested that inaccuracies in creep data may arise as a result of the cross-sectional losses of the specimens. This inaccuracy may also cause discrepancies in life assessment.

FIGURES IN THIS ARTICLE
<>
Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 6

SEF kinetics of Cr-Mo steels at (a)500°C, (b)600°C, and (c)700°C

Grahic Jump Location
Figure 7

Extrapolated stress enhancement factor for 1.25Cr-0.5Mo and 2.25Cr-1Mo steels at 500–700°C for 100,000h: (a)1.25Cr-0.5Mo steel and (b) the present work of 2.25Cr-1Mo steel compared with the work of Bueno and Marino (10)

Grahic Jump Location
Figure 1

Oxidation kinetics of Cr-Mo steels at 500–700°C: (a)1.25Cr-0.5Mo and (b)2.25Cr-1Mo steels

Grahic Jump Location
Figure 2

Morphology and chromium-iron ratio profile of cross sections of 1.25Cr-0.5Mo and 2.25Cr-1Mo steel specimens air oxidized at 500°C for 600h: (a) backscattered electron (BSE) image of 1.25Cr-0.5Mo steel; (b) EDXS chromium line profile (expressed as the Cr∕Fe ratio) of 1.25Cr-0.5Mo steel; (c) BSE image of 2.25Cr-1Mo steel; and (d) EDXS chromium line profile of 2.25Cr-1Mo steel

Grahic Jump Location
Figure 3

Morphology and chromium-iron ratio profile of cross sections of 1.25Cr-0.5Mo and 2.25Cr-1Mo steel specimens air oxidized at 600°C for 1000h: (a) BSE image of 1.25Cr-0.5Mo steel; (b) EDXS chromium line profile (expressed as the Cr∕Fe ratio) of 1.25Cr-0.5Mo steel; (c) BSE image of 2.25Cr-1Mo steel; and (d) EDXS chromium line profile of 2.25Cr-1Mo steel

Grahic Jump Location
Figure 4

Morphology and chromium-iron ratio profile of cross sections of 1.25Cr-0.5Mo and 2.25Cr-1Mo steel specimens air-oxidized at 700°C for 300h: (a) BSE image of 1.25Cr-0.5Mo steel; (b) EDXS chromium line profile (expressed as the Cr∕Fe ratio) of 1.25Cr-0.5Mo steel; (c) BSE image of 2.25Cr-1Mo steel; and (d) EDXS chromium line profile of 2.25Cr-1Mo steel

Grahic Jump Location
Figure 5

SEF kinetics of Cr-Mo steels at 500–700°C for (a)1.25Cr-0.5Mo steel and (b)2.25Cr-1Mo steel

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In