Forging Overview: Hot vs Cold
锻造概述：热锻与冷锻
标签：锻造, 热锻, 冷锻, 概述
锻造是通过锤击使金属塑性变形的工艺，不去除材料。热锻在再结晶温度以上进行（紫铜约 500–700℃、黄铜约 600–750℃），金属柔软、变形大、不易裂；冷锻在室温，强度更高、尺寸精，但变形量受限且有加工硬化。铜及铜合金多为热锻起步再冷锻收形。锻造能细化晶粒、提升致密度与机械性能，是器皿、刀具、首饰的重要成形法。
Forging shapes metal by hammering — no material removed. Hot forging is above recrystallization (copper ~500–700℃, brass ~600–750℃): soft, large deformation, less cracking. Cold forging is at room temp: stronger, precise, but limited deformation and work-hardening. Copper alloys usually start hot then finish cold. Forging refines grain, increases density and strength — key for vessels, blades, jewelry. ---