Technology for electroplating tungsten-cobalt-iron-cerium alloy on surface of structural steel

Abstract

The invention discloses a technology for electroplating a tungsten-cobalt-iron-cerium alloy on a surface of structural steel. A plating solution adopted by the technology is composed of 32-36 g / L of cobalt sulfate, 80-84 g / L of sodium tungstate, 22-26 g / L of ferrous sulfate, 1.5-2.5 g / L of cerium sulfate, 34-38 g / L of boric acid, 30-36 g / L of sodium sulfate, 20-24 g / L of ammonium sulfate, 30-34 g / L of tartaric acid, 11-15 g / L of potassium pyrophosphate, 10-14 g / L of ascorbic acid, 1-3 ml / L of formaldehyde, 2-4 ml / L of dimethyl hexynol, 4-6 mg / L of thiourea, and the balance being water. The technology comprises the steps of washing and activating the structural steel by removing oil; then putting the structural steel in the above plating solution to be used as a cathode; taking stainless steel as an anode; adjusting a pH value to 3.5-4.5 with acetic acid; heating to a temperature of 50-60 DEG C; controlling a current density at 12-16 A / dm<2> and electroplating for 20-30 minutes.

Description

technical field [0001] The invention relates to the technical field of electroplating, in particular to a process for electroplating a tungsten-cobalt-iron-cerium alloy on the surface of structural steel. Background technique [0002] With the rapid development of modern automobile industry, machinery industry, aviation and aerospace industry, more and more high-load cylinder pistons and sliding parts are used under the action of dry friction, hydraulic pressure and lubricating oil medium. Electroplating high-hardness, high-temperature-resistant, corrosion-resistant and fatigue-resistant coating materials on the surface of sliding parts is an effective way to solve the problem of sintering and strain on the surface of parts due to temperature rise during friction, which can greatly improve the service life of equipment. , increasing the economic cost. [0003] Hard chrome coating has good hardness, wear resistance and corrosion resistance, and hard chrome plating on the sur...

AI Technical Summary

Problems solved by technology

However, nickel-based alloy coatings are not up to the requirements of hard chrome coatings in terms of wear resistance and hardness.

Nickel-based alloys are face-centered cubic lattices, and in the process of rubbing against the counterpart metal, they tend to be severely adhered to the counterpart metal, thereby aggravating wear and having poor wear resistance

At the same time, the hardness of the nickel-based alloy coating is not high. For nickel-tungsten alloys, when the tungsten content in the alloy coating exceeds 30%, the microhardness value is 400-600Hv, which must be subjected to high-temperature heat treatment (300-500°C ) can make its hardness reach about 1000Hv, and after heat treatment, the brittleness of the nickel-tungsten coating increases significantly, and the bonding force between the coating and the base material is very poor, and it is easy to peel off, which is difficult to have practical application value

[0004] Therefore, there is no particularly suitable substitute for the chrome-plated layer in the prior art. Because people pay more and more attention to environmental protection, the chrome-plated process and products that will bring a lot of pollution in the production process urgently need a new process and product replacement