کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1578592 | 1514818 | 2011 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Micro-structural strengthening mechanism of multiple laser shock processing impacts on AISI 8620 steel Micro-structural strengthening mechanism of multiple laser shock processing impacts on AISI 8620 steel](/preview/png/1578592.png)
Micro-structural evolution in the near-surface region of AISI 8620 steel subjected to multiple laser shock processing (LSP) impacts were investigated by means of cross-sectional optical microscopy (OM) and transmission electron microscopy (TEM) observations. Micro-structural evolution process subjected to multiple LSP impacts can be described as follows: (i) the parallel lamellar pearlites are broken into bitty pearlites, and dislocation activities simultaneously led to the formation of dislocation lines (DLs) and dislocation pile-ups in original grains; (ii) bitty pearlites were all broken into Fe3C granules, and dislocation movement made Fe3C granules disperse near subgrain boundaries and led to subgrain boundaries separating individual cells, and (iii) subgrain boundaries were refined to grain boundaries. Multiple LSP impacts on AISI 8620 steel had dual-function: the refinement of coarse grains in the near-surface region by dislocation movement and dispersion strengthening of C atoms which cut cementite and diffused into the ferrite by moving dislocations.
► LSP can clearly refine coarse grains in the shocked region by dislocation movement.
► Micro-structural evolution of AISI 8620 steel after LSP impacts is revealed.
► LSP on AISI 8620 steel have grain refinement and dispersion strengthening of carbon.
► The results can provide some insights on surface modification of low carbon steel.
Journal: Materials Science and Engineering: A - Volume 528, Issues 19–20, 25 July 2011, Pages 6128–6133