Chromium-free Passivation Recipe for Medals
纪念章无铬钝化封护配方
标签：无铬钝化, BTA, 环保, 封护, 纪念章, 法规
欧盟 REACH 限制六价铬钝化后，纪念章后处理转向苯并三氮唑（BTA）体系：BTA 0.5–1 wt%，60–70 °C 浸泡 5–10 min，形成 Cu(I)-BTA 络合膜约 50 nm，中性盐雾可达 72–96 h 无明显变色。黄铜章可先 1% 硫酸活化 10 s 再钝化。该配方不含铬，废水仅需常规中和处理，成本比镀铬封护低约 40%。
With hexavalent chromium restricted under REACH, medal finishing has moved to benzotriazole: dip in 0.5–1 wt% BTA at 60–70 °C for 5–10 min to grow a ~50 nm Cu(I)-BTA film that survives 72–96 h of neutral salt spray. Activate brass in 1% sulfuric acid for 10 s first. Chromium-free effluent needs only neutralization and total cost runs ~40% below chrome-based sealing.