The spiral plate heat exchanger is a gas pressurizing component of the oxidizer tank in the whole engine system, which is used to provide the propellant supply pressure required for the normal operation of the engine. In the development process, the design requires that the inner and outer brazed and non brazed surfaces of the spiral plate heat exchanger be electroplated with Ni10~15 μ M, in which the coating on the brazing surface is required for subsequent welding with other components, and the coating on the non brazing surface is used as the high-temperature oxidation resistance protective coating during operation.

The application of nickel coating can be divided into two aspects: protection and decoration and functionality. As the protective and decorative coating of spiral plate heat exchanger, nickel can be plated on the surface of low carbon steel, zinc castings, some aluminum alloys and copper alloys to protect the base material from corrosion, and bright nickel coating can be obtained by polishing the dark nickel coating or directly plating bright nickel, so as to achieve the purpose of decoration. In fact, we all know that plastics can also be plated with nickel after treatment to metallize plastic parts. For functional applications, the worn, corroded, or over machined spiral plate heat exchanger parts are plated for repair.

Therefore, it is generally not used as the protective coating of steel substrate of spiral plate heat exchanger, but as the intermediate layer and bottom layer of protective decorative coating system. The bright nickel coating obtained from the solution with brightener has brittleness and poor protection ability. However, nickel has good shielding effect and strong electromagnetic interference resistance, so it is applied to the surface treatment of mechanical box.