Evaluation of Nondestructive Instruments for Wire Rope

摘要

The critical importance of wire rope integrity to the mining industry has led tothe creation of standards for the retirement of wire rope, as well as to the development of electromagnetic devices and procedures that would allow wire ropes to be tested against these standards without destroying them. The U.S. Bureau of Mines conducted research to evaluate these devices by measuring loss of metallic cross-sectional area and the number of wire breaks, or local faults. The intent was to define the extent to which the technique can identify degradation within the rope, e.g. broken wires, corrosion, and wear. Experimental results showed that instrument sensitivity depended on a number of factors, including rope diameter, placement of sensors, location and characteristics of flaws, rope speed, and tension on the rope. The experiments also demonstrated the importance of having an elongated recorder trace and a properly trained and experienced operator to interpret overall results. A design of a rope and test procedures for use in laboratory evaluation of instruments have been recommended by the American Society for Testing and Materials (ASTM) Committee E07.07.10, Wire Rope Applications. The Bureau is working through this committee to develop standards for an electromagnetic method of wire rope inspection.