Microstructure Aspects Of Work-softening Phenomenon For Steel And Aluminum

Author:  Hailin, Mingzhi, Jiawen, Iida
Source:  Conf Proc: ICSP-4, (p.227-232)
Doc ID:  1990043
Year of Publication:  1990
Experiments were designed to reveal the nature of work softening aspect of shot peening. A steel specimen is compressed in different strains and then tensiled. The half width decreases to a minimum value and increases again, that agrees with the hardness distribution of a softened layer of peened specimen. Microstructure analysis of A1 specimen shows the reverse loading makes the cell structure indistinct and forms dislocation networks, but in further loading, the well formed cells establish again thus the material becomes hardened. Below the strain threshold of softening, the material increases its half width under cyclic loading, but its residual stresses decay with the cycle number. Descriptors: Half width; Softening; Shot peening

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