RESEARCH PAPERS: New Investigations Relating to Stress Concentrations Under Creep Conditions

Cumulative Damage in Creep-Rupture Tests of a Carbon Steel

[+] Author and Article Information
P. N. Randall

Materials Department, Space Technology Laboratories, Los Angeles, Calif.

J. Basic Eng 84(2), 239-242 (Jun 01, 1962) (4 pages) doi:10.1115/1.3657295 History: Received May 25, 1961; Online November 04, 2011


A life-fraction rule is often used to predict the rupture life of a piece of elevated-temperature equipment exposed to several temperature and stress conditions. It is based on the assumption that the fraction of rupture life used up in a specific time at one stress and temperature is independent of previous conditions and therefore can be estimated from tests in which exposure conditions were held constant. Test data are needed to substantiate the validity of this rule. The results of 23 constant-stress creep-rupture tests on an ASTM A201A carbon steel have shown this rule to be valid when all of the test conditions caused appreciable creep strain. Even so, it may not be valid for prolonged service above 1100 F followed by service at lower temperatures. Creep rates are reasonably predictable for constant-stress conditions when only temperature is changed. The transient creep rate accompanying a change in stress continues long enough to make creep-rate predictions unreliable. Periodic shutdowns during tests at constant stress and constant temperature have little effect on either rupture life or creep rate.

Copyright © 1962 by ASME
Your Session has timed out. Please sign back in to continue.






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