Trivalent Chromium Plating: Cr(VI) Alternative
三价铬电镀替代六价铬
标签：三价铬, 无氰电镀, Cr(VI)替代, 环保工艺, 电镀
三价铬镀液（硫酸铬 20–30 g/L、甲酸络合剂 10–15 g/L、硼酸缓冲 40 g/L，pH 3.5–4.0，温度 45–55℃，电流密度 5–10 A/dm²）替代剧毒六价铬工艺，电流效率 15–25%，沉积略慢。阳极用石墨而非铅锑合金，避免六价铬再生。镀层微孔无裂纹，耐蚀性可经后续钝化提升；pH 与温度波动控制在 ±2℃ 内以保证色泽一致。
Trivalent chromium baths (chromium sulfate 20–30 g/L, formate complexant 10–15 g/L, boric acid buffer 40 g/L, pH 3.5–4.0, 45–55℃, 5–10 A/dm²) replace toxic hexavalent processes at 15–25% current efficiency. Use graphite anodes, not lead-antimony, to avoid Cr(VI) regeneration. Deposits are micro-crack-free; corrosion resistance improves with post-passivation. Hold pH and temperature within ±2℃ for consistent color. ---