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Kim, Jong Do;Choi, So Young;Lee, Su Jin;Suh, Jeong
- Transactions of the Korean Society of Mechanical Engineers A
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- v.38 no.12
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- pp.1367-1372
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- 2014
As the awareness of the environmental crisis has recently increased around the world, numerous studies in the transport industry have been conducted to solve this problem through lightweight car bodies. The hot-stamping process has been presented as solution to achieve a light weight. Hot-stamping is a method that is used to obtain ultra-high strength steel (1,500 MPa or greater) by simultaneously forming and cooling boron steel in a press die after heating it to a temperature of $900^{\circ}C$ or above. This study involved a, fundamental examination of laser parameters to investigate the laser weldability of boron steel. As a result, the following optimum parameters for the shielding gas were found: Q = 20 l/min, ${\alpha}=40^{\circ}$, d = 20mm, and l = 0 mm. The hardness of butt weldment increasesed sharply as a result of martensite formation at the fusion zone.
https://doi.org/10.3795/KSME-A.2014.38.12.1367 인용 PDF KSCI

Kim, Y.I.;Kim, J.H.;Kim, Y.;Lee, M.Y.;Moon, Y.H.;Kim, D.
- Transactions of Materials Processing
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- v.20 no.8
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- pp.568-574
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- 2011
The combination of tailor welded blank (TWB) and hot stamping often offers improved crash-worthiness and reduced mass of stamped parts in the automobile body. To investigate the formability of laser TWB and the reliability of weld line, the present study used 22MnB5 boron steel sheet of the same thickness and used the Erichsen cupping test at elevated temperatures. The effects of laser direction, die temperature, weld line positions and forming speed on formability(the limiting dome height) were studied and the results were compared with the formability of the base material.
https://doi.org/10.5228/KSTP.2011.20.8.568 인용 PDF KSCI

Yang, Li;Kang, Chung-Gil
- Proceedings of the Korean Society for Technology of Plasticity Conference
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- 2009.10a
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- pp.375-378
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- 2009
Hot press forming is a new forming process which also names as hot stamping. It can greatly enhance the formability of forming parts. This paper researches the formability of boron steel sheet in hot bending process which is a kind of hot press forming. In the text, the influence of hot press forming processing parameters, such as the heating temperature, blank holding force, punch speed and punch and die radius, on the mechanics properties and microstructure of the hot bending parts was analyzed by tension test and the metallographic observation on the parts with various processing parameters. The relationship between blank holding force and punch load was also presented.
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Yoo, Ji-Hong;Nam, Seung-Man
- Transactions of the Korean Society of Automotive Engineers
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- v.18 no.5
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- pp.25-30
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- 2010
The authors have studied on the corrosion resistance of the hot stamped steel sheets for the application to automotive parts. Recently automotive companies have focused on the hot stamped parts to meet the light weighting needs and the safe reason. Because of the cost reduction of the hot stamped parts, automotive companies increase the usage of the coated steel sheets, especially Al-Si coated steel sheets. The coated layer of Al-Si coated steel sheets contains up to 50% of Fe, which was diffused from the steel sheet, after hot stamping. The hot stamped steel sheet was not phosphated due to the oxidation layer of the coating, however, the result of the water resistance test is similar to that of the conventional GA steel sheets. The pitting depth and the weight reduction of the coated layer of hot stamped steel sheets are less than those of GA steel.
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