Campus Units

Materials Science and Engineering, Chemical and Biological Engineering

Document Type

Article

Publication Version

Published Version

Publication Date

2015

Journal or Book Title

Advanced Materials Letters

Volume

6

Issue

9

First Page

783

Last Page

789

DOI

10.5185/amlett.2015.5838

Abstract

Anhydrous ammonia is a toxic material that is transported from distribution centers to farm fields in steel pressure vessels called nurse tanks. Numerous accidents have occurred in which nurse tanks failed and ammonia was released, often with explosive force. The majority of such accidents are caused by stress corrosion cracking of the tank steel. Stress corrosion cracking is caused by the combination of stress in the tank's steel and the corrosive effect of ammonia. Neutron diffraction analysis was used to map the residual stress state in and near circumferential welds from two used anhydrous ammonia nurse tanks, one manufactured in 1966 and the other manufactured in 1986. Notched SA455 steel test specimens were held under tensile load (stress concentration factors of 40 to 80 MPam) while immersed in NH3 for seven months to generate crack propagation rate data. The results from these measurements were then used to predict stress corrosion crack growth rates for various pre-existing crack sizes at various temperatures. These data may be useful for estimating safe service lifetimes of nurse tanks that contain cracks.

Comments

This article is published as A.T. Becker, A.M. Russell, and L.S. Chumbley, “Predicted Growth of Through-Thickness Stress Corrosion Cracks in Anhydrous Ammonia Nurse Tanks”, Adv. Mat. Let., 6 (9), 783-789, 2015, doi:10.5185/amlett.2015.5838. Posted with permission.

Copyright Owner

VBRI Press

Language

en

File Format

application/pdf

Included in

Metallurgy Commons

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