针对无取向电工钢经蒸汽发蓝处理后,其铬酸镁涂层中出现六价铬含量超标的问题,利用紫外可见光分光光度计和气氛热处理等方法研究了不同气氛下发蓝工艺对无取向电工钢涂层中六价铬含量的影响。结果表明:在N₂气氛及还原性气氛条件下,随着发蓝时间的延长和温度的升高,涂层中六价铬的含量均会降低,但在较低的发蓝温度下,涂层六价铬的含量下降不明显;要彻底解决六价铬含量超标的问题,必须确保涂层烘烤固化后,材料的六价铬含量达标。

Aiming at the problem that the content of hexavalent chromium in the magnesium chromate coating of non-oriented electrical steel after steam bluing treatment exceeded the standard, the effects of bluing process on the content of hexavalent chromium in the coating of non-oriented electrical steel under different atmospheres were studied by means of ultraviolet-visible spectrophotometer and atmosphere heat treatment. The results show that under the condition of N₂ atmosphere and reducing atmosphere, the content of hexavalent chromium in the coating would decrease with the extension of blueing time and the increase of temperature. However, the content of hexavalent chromium in the coating did not decrease significantly at lower blueing temperature. In order to completely solve the problem of excessive hexavalent chromium content, it was necessary to ensure that the hexavalent chromium content of the coating reached the standard after baking and curing.