Method for plating hard chromium in trivalent chromium bath for forming thick plated layer

• Main Authors: ZHAO WENJUN, YAO WEI, SHANG ZHIQUAN, HOU YU, WANG WEN, LI GUOSHENG, LI LIANXI, LIU BIN, SUN NING, BAO MIN, YANG ZHIGANG, SONG QIANG, LI JIAZHU, SHI BAOWEN, SUN XUANJIE, ZHAO YINHU, LI GUIHUA, ZHANG WEIDONG, LI WENGANG
• Format: Patent
• Language: Chinese; English
• Published: 15.08.2012
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; METALLURGY; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS

The invention relates to a method for plating hard chromium in trivalent chromium bath for forming a thick plated layer. The present problem that the thick plated layer cannot be formed on the surface of a workpiece by taking a sexivalent chromium salt as electroplating solution is solved. The technological conditions for electroplating chromium are as follows: adding a defined amount of BSG12 type trivalent chromium electroplating solution into a plating tank according to the size of the workpiece, wherein the electroplating solution meets the demands on: temperature at 15-35 DEG C, current density of 15-45 A/dm2 and PH value of 1.5-2.2; adjusting by using dilute sulphuric acid or sodium carbonate; taking a DSA anode as anode; keeping a distance between cathode and anode within a range of 35mm to 45mm; while electroplating, keeping volume current density less than or equal to 9.8A/L; when electroplating work load reaches 30AH/L, supplementing 50ml/L BSG12 type trivalent chromium electroplating solution; repe