| 摘要 |
A hot-dip Sn-Zn system coated steel sheet comprising a steel sheet and a hot-dip coating layer which is formed on the surface of the steel sheet and comprises 1 to 8.8% by mass of Zn and a remainder composed of 91.2 to 99.0% by mass of Sn and impurities, the ratio of the endothermic value produced by the Sn-Zn eutectic crystal melting and the endothermic value produced by the Sn primary crystal melting in the hot-dip coating layer satisfying the following formula: (endothermic value produced by Sn primary crystal melting)/[(endothermic value produced by Sn primary crystal melting)+(endothermic value produced by Sn-Zn eutectic crystal melting)] >= 0.3; and the temperature of endothermic peak produced by the Sn primary crystal melting being not lower than 200‹C and not higher than 230‹C or lower and that produced by the Sn-Zn eutectic crystal melting being not lower than 198‹C and lower than 200‹C. ® KIPO & WIPO 2008 |
