Excerpt from Nondestructive Testing of Wire Hoisting Rope by Magnetic AnalysisThe material represented by record No. 1, Figure 4, is one example. It was found in this case ihat the magnetic variations increased in magnitude if the magnetizing force was increased. This would ap pear to indicate that the irregularities were not due to internal stress. A definite periodicity in the curve was noted which was finally found to be associated with the circumference of the 8-inch roll with which the wire was rolled from the round to the stream-line section. Two other wires from the same source gave practically identical curves. In this case variations in magnetic permeability of considerable magnitude were probably the result of relatively small variations in the amount of cold work, resulting in permanent deformation as distinguished from the temporary condition of stress within the elastic limit, and did not indicate a dangerous condition.Thus it is seen that the reactions of the magnetic properties of steel to various in¿uences do not necessarily correspond either in direction or magnitude with the effect of these in¿uences on the mechanical properties.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.