航天标准件螺母滚镀锌工艺

Barrel zinc plating of nuts for aerospace fasteners

对不同螺纹孔深度的45钢螺母（重约3g）进行滚镀锌,镀液组成和工艺条件为：NaCN100~120g/L,NaOH80~100g/L,ZnO40~50g/L,Na2S1~5g/L,装载量30~45g/L,室温,电流300~400A,转动线速率40mm/s.本工艺适用于螺纹孔深径比大于1.0∶1.5的螺母,所得镀层厚度均匀,外观和结合力良好,耐蚀性满足QJ452–1988的要求.

Barrel zinc plating was carried out for nuts made of 45 steel （about 3 g per each） with different thread hole depths. from a bath composed of NaCN 100-120 g/L, NaOH 80-100 g/L, ZnO 40-50 g/L, and Na2S 1-5 g/L under the conditions of room temperature, current 300-400 A, loading capacity 30-45 g/L, and liner rate of rotation 40 mm/s. The given process is suitable for the nuts with a ratio of thread hole depth to diameter higher than 1.0：1.5. The obtained zinc coatings feature a uniform thickness, good appearance and adhesion, and a corrosion resistance meeting the requirement of QJ 452-1988 standard.