Case: Copper Hot-pot Deep Drawing
案例：紫铜火锅深拉深成型
标签：铜火锅, 多道拉深, 退火, 实际工艺
直径 280 mm、深 180 mm 的紫铜火锅采用 Ø360 坯料，经 3 道拉深（减径 18%/15%/12%）+ 2 次 550℃ 退火成型，末道带凸缘整形。关键点：每道后手工抛光去除拉痕，退火用氮气保护避免氧化发黑，成品壁厚均匀、口沿圆顺，再经錾刻与煮黑做旧。
A 280 mm-diameter, 180 mm-deep copper hot-pot starts from a Ø360 blank and is formed by 3 draws (18%/15%/12% reduction) plus two 550℃ anneals, ending with flanged sizing. Key points: hand-polish draw marks after each pass, anneal under nitrogen to avoid blackening, achieve even wall and smooth rim, then chase and apply a blackened antique finish. ---