1. A method of inducing rapid failure in a shape that is under stress and is composed of cold rolled steel comprising applying against a surface of said cold rolled steel shape a mixture composed of lithium metal, lithium chloride and potassium chloride, rapidly heating that mixture as well as the surface of the steel shape in contact therewith sufficiently to melt the mixture but below the annealing temperature of the steel, and maintaining that temperature until the steel shape cracks.