Choosing a Laser-Cutting Technology to be Applied to a Deep-Drawn Product

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Residual stresses are an inevitable result of mechanical and heat treatments of steel. The stress field generated at the surface and through the cross section of a product is usually non-uniform, and there can be important stress gradients. In general residual stresses can be defined as self-balanced internal stresses existing in a free body on which no external forces are acting. In the present study the focus was on the residual stresses occurring in a steel deep-drawn product of a complex form. The residual stresses occur mainly because of different degrees of plastic deformation at different locations. The residual stresses occurring in the product as a result of the manufacturing process of deep drawing can be comparatively strong. In slitting or cutting a useful product out of a deepdrawn part by laser cutting, a portion of the residual stresses will get relieved and produce distortion of the deep-drawn product. The studies made showed that the distortion of the deep-drawn product depended on the mode of cutting-out. Also the state of the residual stresses after slitting or cuttingout of the deep-drawn product will depend on the mode of cutting-out, i.e., on the sequence of individual cuts chosen. The product used in the analysis made was a deep-drawn steel mud-guard, which makes a component part of a working machine. The various modes of cutting-out a useful product of 1260x800x370 mm in size were performed with laser cutting using cutting oxygen. The residual stresses in the mud-guard were determined with a semi-destructive hole drilling strain gage method.

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Periodical:

Materials Science Forum (Volumes 537-538)

Edited by:

J. Gyulai and P.J. Szabó

Pages:

639-646

Citation:

J. Grum and T. Kek, "Choosing a Laser-Cutting Technology to be Applied to a Deep-Drawn Product", Materials Science Forum, Vols. 537-538, pp. 639-646, 2007

Online since:

February 2007

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$38.00

[1] Z. Wang, B. Gong: Residual Stress in the Forming of Materials; Handbook of residual stress and deformation of steel, Ed.: G.E. Totten, Materials Park, ASM International, 2002, pp.141-150.

[2] J.M. Slabe, T. Kek, J. Grum: Measurement of acoustic emission and deformations in laser cutting of deep-drawn sheet parts. 8th Int. Conf. of the Sovenian Society for NDT, Portorož, Slovenia, 1-3 September 2005. Conf. proc. Slovenian Society for NDT, 2005, pp.323-333.

DOI: https://doi.org/10.1504/ijmmp.2006.011653

[3] G.S. Schajer: Application of Finite Element Calculation to Residual Stresses by the Hole drilling Method; Journal of Engineering Materials and Technology, 103 (1981): pp.157-163.

[4] Determining Residual Stresses by the Hole-Drilling Strain-Gage Method: ASTM Standard E837.