Document Type

Technical Report

Publication Date

7-7-2005

Publisher

Metallurgical and Materials Engineering, University of Nevada, Reno

Abstract

This report encompasses the work done for this third quarter, 2005, in accordance to cooperative agreement of University of Nevada system for the Task 019 “Subsurface Corrosion Research on Rock Bolt System, Perforated SS Sheets and Steel Sets for the Yucca Mountain Repository”, the overall objective of which is to conduct corrosion research and predict the durability of rock-bolts and other underground metallic roof supports. We have started oxidation tests using Thermogravimetric Analyzer (TGA), and Potentiodynamic tests to determine the corrosion rates of rock bolts, other support materials including bench mark materials.

In this quarter, we have also performed hydrogen permeation tests on Williams rock bolts (from YM site). We discuss “dry” oxidation of rock bolt steels and other supporting materials that are susceptible to oxidation under the repository conditions. Swellex rock bolts (made by Atlas Copco) and Split Sets rock bolt (HSLA steel made by “International Rollforms”) were tested up to 500C using Modulated Thermogravimetric Analysis (MTGA) method under pure O2 atmosphere. In addition, a mechanism for weight loss in initial stages isothermal oxidation test of Alloy 22 in pure O2 atmosphere 980C using standard TGA was also determined (the experiments were reported in the last quarterly report). It has been concluded that this initial weight loss is primarily due to formation TCP phases on grain boundaries; proof of which is shown in scanning electron micrographs.

Keywords

Nevada – Yucca Mountain; Radioactive waste repositories; Rock bolts – Corrosion; Stainless steel – Stress corrosion

Disciplines

Materials Science and Engineering | Metallurgy | Structural Materials

Language

English

Comments

Task ORD-FY04-019
Document No: SIP-UNR-040
DOE/UCCSN Cooperative Agreement Number DE-FC28-04RW12232

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