0
Research Papers: Materials and Fabrication

A Review of the Effects of Coolant Environments on the Fatigue Life of LWR Structural Materials

[+] Author and Article Information
O. K. Chopra, W. J. Shack

Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL 60439

J. Pressure Vessel Technol 131(2), 021409 (Jan 23, 2009) (21 pages) doi:10.1115/1.3027496 History: Received July 19, 2007; Revised January 02, 2008; Published January 23, 2009

The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code specifies design curves for the fatigue life of structural materials in nuclear power plants. However, the effects of light water reactor (LWR) coolant environments were not explicitly considered in the development of the design curves. The existing fatigue-strain-versus-life (ε-N) data indicate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. Under certain environmental and loading conditions, fatigue lives in water relative to those in air can be a factor of 15 lower for austenitic stainless steels and a factor of 30 lower for carbon and low-alloy steels. This paper reviews the current technical basis for the understanding of the fatigue of piping and pressure vessel steels in LWR environments. The existing fatigue ε-N data have been evaluated to identify the various material, environmental, and loading parameters that influence fatigue crack initiation and to establish the effects of key parameters on the fatigue life of these steels. Statistical models are presented for estimating fatigue life as a function of material, loading, and environmental conditions. An environmental fatigue correction factor for incorporating the effects of LWR environments into ASME Code fatigue evaluations is described. This paper also presents a critical review of the ASME Code fatigue design margins of 2 on stress (or strain) and 20 on life and assesses the possible conservatism in the current choice of design margins.

Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic of (a) the growth of short cracks in smooth specimens as a function of fatigue life fraction and (b) crack velocity as a function of crack depth

Grahic Jump Location
Figure 2

Depth of largest crack plotted as a function of fatigue cycles for (a) A533-Gr. B low-alloy steel and (b) Type 304 and 316L SSs in air and LWR coolant environments

Grahic Jump Location
Figure 3

Photomicrographs of fatigue cracks on gauge surfaces of A106-Gr. B carbon steel in (a) air and (b) high-DO water at 288°C(550°F)

Grahic Jump Location
Figure 4

Dependence of fatigue life of (a) carbon steel and (b) low-alloy steel on strain rate

Grahic Jump Location
Figure 5

Effect of surface roughness on fatigue life of (a) A106-Gr. B carbon steel and (b) A533 low-alloy steel in air and high-purity water at 289°C(552°F)

Grahic Jump Location
Figure 6

Dependence of fatigue lives of austenitic stainless steels on strain rate in low-DO water

Grahic Jump Location
Figure 7

Dependence of fatigue life of (a) Type 304 and (b) Type 316NG stainless steels on strain rate in high- and low-DO water at 288°C(550°F)

Grahic Jump Location
Figure 8

The effect of material heat treatment on fatigue life of Type 304 stainless steel in air, BWR, and PWR environments at 289°C(552°F), ≈0.38% strain amplitude, sawtooth waveform, and 0.004%∕s tensile strain rate

Grahic Jump Location
Figure 9

Effect of water flow rate on the fatigue life of austenitic SSs in high-purity water at 289°C(552°F) (Ref. 19)

Grahic Jump Location
Figure 10

Effect of surface roughness on fatigue life of (a) Type 316NG and (b) Type 304 stainless steels in air and high-purity water at 289°C(552°F)

Grahic Jump Location
Figure 11

Fatigue ε-N behavior for (a) Alloy 600 and (b) Alloy 82, 182, and 132 weld metals in air at various temperatures. The arrows represent run offs.

Grahic Jump Location
Figure 12

Dependence of fatigue lives of Alloys 690 and 600 and their weld alloys in PWR water at 325°C(617°F) and Alloy 600 in BWR water at 289°C(552°F)

Grahic Jump Location
Figure 13

Estimated cumulative distribution of constant A in statistical models for fatigue life with heats of carbon and low-alloy steels and austenitic stainless steels in air

Grahic Jump Location
Figure 14

Estimated cumulative distribution of parameter A in statistical models that represent the fatigue life of test specimens and actual components in air

Grahic Jump Location
Figure 15

Fatigue design curves for carbon and low-alloy steels and austenitic SSs in air

Grahic Jump Location
Figure 16

Application of the modified rate approach to determine the environmental fatigue correction factor Fen during a transient

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