Cold-drawing applied stress

The simplest type of stress that can be applied to a polymer is a tensile stress, so the behaviour of polymers under such a stress is described before more general forms of stress are considered. This leads directly to a discussion of necking and cold drawing. 

Because the stress applied during cold-drawing programming is usually very large as compared to the classical programming above the transition temperature, it is interesting to find... 

The orientation in the direction of applied stress occurs also in amorphous materials. The amorphous polymers, like the crystalline ones, also exhibit increased strength in the direction of orientation. If there is a small amount of crystallinity in polymers, the crystallinity often increases as a result of cold drawing. 

Key factors of SCC. The stress applied on a metal is nominally static or slowly increasing tensile stress. The stresses can be applied externally, but residual stresses often cause SCC failures. Internal stresses in a metal can be due to cold work or a heat treatment. In fact, all manufacturing processes create some internal stresses. Stresses introduced by cold work arise from processes such as lamination, bending, machining, rectification, drawing, drift, and riveting. Stresses introduced by thermal treatments are due to the dilation and contraction of metal or indirectly by the modification of the microstructure of the material. Welded steels contain residual stresses near the yield point. Corrosion products have been shown to be another source of stress and can cause a wedging action. 

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