坯料感应加热工艺与温度管控｜Induction Heating of Billets: Soak, Overheat and Temperature Control

摘要：坯料加热的目标不是「烧红」，而是芯表温度均匀、达到合适锻造温度且不过热过烧。讲感应加热的透热控制、温度区间、四类工艺缺陷与批次追溯。
Abstract: The goal of heating is not a red surface. It is a billet at forging temperature with the core as hot as the skin, and no overheating. Through-heating, temperature windows, four defect modes, and batch traceability.

正文： 坯料加热核心目标：把坯料加热到合适锻造温度，芯部与表面温度均匀，避免过热、过烧。
Main text: The objective in heating is narrow: bring the billet to forging temperature with core and surface in equilibrium, and stop short of overheating or burning.

碳钢、合金钢锻造温度区间参考：普通碳钢始锻温度 1150‑1250℃；终锻温度不低于 800℃；合金钢要根据材质降低始锻温度。
Reference windows: plain carbon steel starts forging at 1,150–1,250 °C and must finish above 800 °C. Alloy grades generally need a lower start temperature, set by the specific material.

一、感应加热的四个关键点
1. Four things that decide the result

1、透热：不能只表面烧红芯部温度低。要匹配棒料直径，控制进给速度、功率，保证芯表温差小。棒料直径越大，需要更长加热时间。
1) Through-heating. A red skin over a cold core is not heated. Match feed rate and power to bar diameter so the core-to-surface difference stays small. The larger the diameter, the longer the residence time required.

2、防止过热过烧：温度过高晶粒粗大，甚至晶界熔化，锻件力学性能直接报废。严格控制最高加热温度。
2) Prevent overheating and burning. Excess temperature coarsens the grain and can melt grain boundaries, which destroys mechanical properties outright. Cap the maximum temperature.

3、氧化控制：尽量缩短高温停留时间，减少氧化皮生成。
3) Control oxidation. Keep time at temperature short to limit scale formation.

4、温度管控：定期校验测温设备；禁止凭肉眼颜色判断温度。
4) Control the measurement. Calibrate pyrometers on schedule, and never judge temperature by eye against colour.

二、三类工艺缺陷
2. Three defect modes

• 欠热：芯部没热透，锻造变形抗力大，充型困难，模具载荷大；
  Under-heating. The core is not soaked, flow stress is high, the die will not fill, and die load climbs.
• 过热过烧：晶粒粗大，锻件韧性差，容易开裂；
  Overheating or burning. Coarse grain, poor toughness, cracking.
• 芯表温差大：表面温度高芯部冷，锻打后组织不均匀。
  A large core-to-surface gradient. The surface is hot and the core cold, and the forging ends up with a non-uniform structure.

三、批次管控
3. Batch records

记录每批次加热工艺参数、实际测温数据，方便质量追溯。
Record the heating parameters and the actual measured temperatures for every batch, so that a quality question can be traced back to a specific run.

小结 坯料加热不是烧红即可，重点管控透热，防止过热过烧；依靠实测温度，不依靠肉眼观察火焰颜色。
In short. Heating is not about getting the billet red. Control through-heating, avoid overheating, and work from measured temperature instead of the colour of the flame.