Bright Annealling
Pre-cleaning Treatment
Raw material coils first undergo acid pickling to remove surface impurities, then pass through a precision cleaning machine to eliminate oil and particulate contaminants—ensuring a pollution-free furnace environment is the “first line of defense” for bright annealing.
Precise Temperature Control in the Furnace
A fully sealed annealing furnace is used, with infrared temperature measurement and PLC systems monitoring the furnace temperature in real time (error ≤ ±5℃). Protective gas (dew point ≤ -60℃) circulates continuously to isolate oxygen—even the furnace walls are coated with special materials to prevent metal ion contamination.
Rapid Cooling for Shaping
After reaching the target temperature, a nitrogen jet system rapidly cools the material (cooling rate: 80-120℃/second). The precise cooling curve locks in the optimal mechanical properties of the material while preventing surface oxidation—this is the key to achieving the “mirror effect.”
Post-Process Surface Inspection
After exiting the furnace, the material is inspected using a 3D surface profiler and gloss meter: surface roughness Ra ≤ 0.05μm (near-mirror finish), gloss ≥ 90° (comparable to polished stainless steel)—every coil must pass dual verification to be deemed “bright annealing qualified.”
