Method for coating, pole tube and device for executing the method

Abstract

A method for coating workpieces which consist of two different metallic materials includes providing the workpiece in a nickel strike electrolyte with a nickel layer as substrate before the application of a corrosion-resistant layer.

Description

technical field [0001] The invention relates to a method for coating a workpiece comprising two different materials, a pole tube with a pole tube section comprising two different materials, and a device for carrying out the method . Background technique [0002] The switching magnet or proportional magnet of the hydraulic solenoid valve usually has a pole tube with an armature space for receiving the armature, the armature rod of the armature runs through the bottom of the pole, and the valve pin of the solenoid valve can be moved by the armature rod. Since the structure of the pole tube is known from the prior art, for example from DE 199 52 800 A1, a detailed description thereof is omitted. [0003] Pole tubes consist of a mix of materials, usually rust- and acid-resistant high-grade steels as well as unalloyed steels such as structural steels St35 or St37. In order to prevent the non-rustproof regions of the pole tubes from being corroded, the pole tubes are traditional...

AI Technical Summary

Problems solved by technology

It can thus occur, for example, that pole tube regions made of high-grade steel are polarized differently during pretreatment than regions made of structural steel—these different polarizations then lead to the occurrence of adhering zinc layers applied later. question

This adhesion problem can then lead to mottled formation through spalling of the zinc layer in areas of high-quality steel

In order to avoid this, specially adapted pretreatment methods are used which, on the one hand, require enormous expenditure in terms of method technology and, on the other hand, do not completely rule out the adhesion problem

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