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장성호;서대교
- Transactions of Materials Processing
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- v.11 no.5
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- pp.423-429
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- 2002
The limiting drawing ratio (LDR) under uniform heating of blanks was measured at the various temperature ranges between 25 and 25$0^{\circ}C$ by using two different blank shapes, square and circular blanks, and six different blank sizes with the drawing ratios(DR) of 2.4 to 2.9. The galvannealed steel sheet (SCP3CM 60/60) of 0.7mm thickness were used. The LDR at warm forming condition reached 1.2 times of that at room temperature, and the maximum drawing depth reached 1.9 times. The higher temperature was adopted, the more stable and uniform thickness strain distribution was observed. Some cases of the experimental results were compared with the analitical results using the commercial finite element method (FEM) code.
https://doi.org/10.5228/KSPP.2002.11.5.423 인용 PDF KSCI

김영근
- Journal of Surface Science and Engineering
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- v.36 no.2
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- pp.176-184
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- 2003
New lubricant film of organic and inorganic composite resin was developed to improve the press formability of galvannealed steel sheets (GA) for automotive body panels. The frictional coefficient of lubricant GA steel sheets is about 20% superior to that of uncoated GA. The current range of spot welding of lubricant GA is similar to that of the uncoated GA, but the burning trace of spot welding is inferior to that of the uncoated GA in the oiling condition. The alkaline degreasability of lubricant GA shows 100% in alkaline degreasing condition of automotive company. The size and shape of the phosphated coating layer are similar to those of the uncoated GA sheet. The powdering property of the lubricant GA gives rise to 20∼50% improved property compared with the uncoated GA sheet.
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문만빈;신철수;오현운;남궁성;박용범
- Proceedings of the Korean Institute of Surface Engineering Conference
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- 2003.05a
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- pp.31-32
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- 2003
In the Present study, the effect of galvannealing conditions on the phase distribution of the Zn-Fe intermetallic phases in the coating layer of the galvannealed steel sheets(GA) was investigated in an interstitial free steel and two kinds of high strength steels. The composition profiles of the coating layers were analyzed using AA and EDS analysis, and the distribution of the intermetallic phases was examined with the aids of X-ray diffraction. On the basis of the pole figure and OIM analyses, it was clarified that the preferred orientation of the $\zeta$ phase depended on the development of the $\gamma$-fibre texture in the substrate.
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