The performance and service life of a chrome-plated roller depend heavily on the precision of its manufacturing process. Below are the key control points.
1. Substrate Preparation
The roller body, typically made of high-strength steel, must undergo rigorous inspection and precision machining. Straightness and concentricity must be kept within tight tolerances (e.g., ≤0.05mm/m) to ensure a uniform plating layer.
2. Surface Texturing (if required)
For applications like cold rolling, the roller surface is textured via shot blasting, EDT, or laser texturing to increase friction and reduce scratches.
3. Electroplating – The Core Step
Hard chromium plating (hardness 800–1100 HV, thickness 50–500 μm) is controlled by key parameters:
Current density – affects grain structure and hardness.
Bath temperature – lower temperature yields a denser layer.
Solution composition – the ratio of chromic acid to sulphuric acid is critical.
Plating time – determines final thickness.
Proper tooling and fixtures are essential for complex roller shapes to ensure uniform current distribution.
4. Post-Plating Finishing
The plated surface is ground and polished to achieve the required roughness (Ra < 0.2μm for high-precision applications). Final inspections include dimensional accuracy, hardness testing, and dynamic balancing.
Conclusion
Strict control at every stage-from substrate to final finishing-directly improves roller durability and surface quality, extending service life by 1–3 times and significantly reducing maintenance costs.
