Electroplating solution and electroplating technology of workpiece inner hole hard chrome

Abstract

The invention discloses an electroplating solution of workpiece inner hole hard chrome. The electroplating solution is prepared from the following raw materials: H2SO4, CrO3 and Cr<3+>, wherein a proportion of the H2SO4 to the CrO3 is (0.8 to 1.2):100. The invention also provides an electroplating technology of the workpiece inner hole hard chrome. The electroplating technology comprises the following steps: (1) workpiece pretreatment; (2) preheating; (3) reversed etching; (4) activating; (5) chrome plating; (6) out of groove of workpiece, and recycling and cleaning;(7) unhanging and polishing; (8) secondary electroplating; (9) checking. According to the electroplating solution and the electroplating technology of the workpiece inner hole hard chrome, provided by the invention, after components and proportion of the electroplating solution are regulated, deposition speeds of the upper end and the lower end of a chrome layer are approximate, and the generation speed of the Cr<3+> is relatively reduced; after the electroplating technology is regulated, the product quality is increased, and the design requirements are met.

Description

technical field [0001] The invention relates to the field of electroplating technology, in particular to a hard chromium electroplating solution for inner holes of workpieces and an electroplating technology thereof. Background technique [0002] At present, the hard chrome plating process for inner holes on the market still has the following disadvantages: (1) there are dendrites (chrome slag) or scorching at the chamfering part; The deposition rate is not uniform. [0003] SO in the inner hole hard chrome plating solution currently on the market 4 2- with Cro 3 The ratio is 1~2:100, which speeds up Cr 3+ generation of SO 4 2- The higher the thickness, the poorer the deep plating ability, the large tolerance size, and the large difference in the deposition speed between the upper and lower ends of the inner hole. Therefore, we need to add 40% of the cost in production, and it is difficult to meet the product design requirements. Contents of the invention [0004] T...

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Problems solved by technology

[0002] At present, the hard chromium plating process for inner holes on the market still has the following disadvantages: (1) there are dendrites (chrome slag) or scorching at the chamfering parts; (2) the thickness of the hard chromium layer is uneven, due to the various uneven deposition rate

[0003] SO in the inner hole hard chrome plating solution currently on the market 4 2- with Cro 3 The ratio is 1~2:100, which speeds up Cr 3+ generation of SO 4 2- The higher it is, the deeper plating ability is poor, the forming tolerance is large, and the deposition speed at the upper and lower ends of the inner hole is very different, so we need to add 40% of the cost in production, and it is difficult to meet the product design requirements

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