LU101954B1 - Process for producing a friction-optimized zinc coating on a steel component - Google Patents

Abstract

The invention relates to a method for producing a friction-optimized zinc coating on a steel component. In order to provide such a method, which leads to a coating with good anti-corrosion properties, good adhesion and a stable, constantly low coefficient of friction even when the steel component is used several times, in particular when it is tightened several times, the method being able to be carried out simply and economically at the same time, it is intended that a zinc layer will first be applied to the surface of the steel component by means of a galvanic deposition process and then heat treatment at a temperature below 420 °C for the targeted formation of intermetallic zinc-iron phases in the galvanically deposited zinc layer to optimize the coefficient of friction the steel component is made.

Description

LU101954 | Process for producing a friction-optimized zinc coating on a | steel component | The invention relates to a method for producing a friction-optimized zinc coating on a steel component. | Steel component .

are often galvanized in technical applications. In particular filigree bulk | parts, such as screws and clamping sleeves made of steel, are mostly made in the galvanic .

Coated with pure zinc and then passivated. The un- | noble properties of the zinc layer protect the underlying, more noble metal from | Corrosion. Even if a crack occurs, the base material is protected by the anodic | cal effect of the zinc against attack, whereby this itself is oxidized and | can then only guarantee a temporary protective effect. Pure Zinc .

already oxidizes in the air atmosphere and is therefore oxidized by passivation layers | protected. | The deposited layer system consisting of the zinc and the passivation layer = not only the requirement of corrosion protection is made, but | also a high wear resistance and the resulting constant coefficients of friction | required for repeated tightening. For galvanized and passivated steel components .

ten of the prior art, for example in the case of screws, there is, however, a strong fluctuation and a significant increase in the coefficient of friction with repeated ; Men's suit. This results from the layer properties and the adhesive strength of the zinc | layer on the steel base material. In the case of electrical contact elements, a supply | increasing coefficient of friction with repeated tightening of screws also increases. decreasing pressure forces of the conductor against the current bar, resulting in increasing | result in electrical contact resistances that affect the functionality of the contact elements deteriorate. .

| As an alternative to galvanizing, steel components are also often | hot-dip galvanized or sherardized, but in some cases, such as for | filigree scrap parts made of steel, is not economically feasible. In addition, | Hot dip galvanizing to form a zinc coating and particularly to form in- | Termetallic zinc-iron phases with significantly increased coefficients of friction, the friction.

values for a hot-dip galvanized steel screw continue to increase significantly when tightened several times. ! From the document DE 689 12 019 T2 is also already a method for manufacturing | Development of a galvanized tempered steel strip is known in which the first. Steel strip is cleaned and then electrocoated at least one side.

of the steel strip with a zinc coating. Below is the covered . Steel strip conveyed through an induction coil, the strip at a temperature. is heated between 427 °C and 510 °C, resulting in a complete transformation.

of the zinc coating into a zinc-iron alloy coating. Eventually it will. Steel band cooled. However, such a method has the disadvantage that at more.

the melting temperature of the zinc is exceeded during the other process steps, so | that this method on bands and sheets, but not economical on bulk. good parts and smaller steel components, such as screws and clamping sleeves, | can be turned. In addition, such a method leads to a far-reaching conversion | formation of the zinc coating into zinc-iron phases with an iron mass fraction over | 10%, which also leads to a deterioration in the coefficient of friction, in particular | with a multiple tightening, and also to a strong fluctuation of the friction | values of the manufactured and coated steel parts. | The invention is therefore based on the object of providing a method for producing a | to provide a friction-optimized zinc coating on a steel component, | resulting in a coating with good anti-corrosion properties, good adhesion | as well as a stable, constantly low coefficient of friction even with multiple use |.

of the steel component, in particular a multiple tightening, where the | Process can be carried out easily and economically at the same time. | ; The object is achieved according to the invention by a method for producing a friction | value-optimized zinc coating on a steel component according to claim 1 | solved. Advantageous developments are specified in the dependent claims. | In the inventive method for producing a friction-optimized. Zinc coating on a steel component, especially on a bulk part, .

a zinc layer is first applied to the surface of the steel component using a | Nes galvanic deposition process applied and then a heat; treatment at a temperature below 420 °C for the targeted formation of internal | termetallic zinc-iron phases in the galvanically deposited zinc layer for | Optimization of the coefficient of friction of the steel component. | | The inventors have recognized that by means of a heat treatment, the properties | of the zinc-iron phases between the surface of the steel component and the gal- | vanisch applied zinc coating can be specifically controlled and adjusted. be able. This makes it possible to increase the in a simple and repeatable manner.

Adhesion of the zinc layers and an optimization of the zinc layer properties. ten, in particular the layer hardness and the surface friction value. In addition, | the heat treatment has the advantage that it can be used economically for any steel com- | components, also for bulk goods, can be carried out. | In addition, comparative tests have shown that by means of the invention. Measured method well reproducible and without strong fluctuations between a. individual steel components produced according to the invention have a constantly low | Friction can be achieved, even with repeated use of the | Steel component, especially when a screw is tightened several times, | does not increase sharply, but ideally substantially over at least 10 increases. remains unchanged over at least 20 suits. doing | the absolute value of the coefficient of friction is initially of secondary importance, although a low friction | value is particularly preferred. | The steel components can initially be any component from | any iron alloy and preferably an iron-carbon alloy | tion act, which particularly preferably has a carbon mass fraction of below |

-4- .

2%. Each individual steel component is preferably formed in one piece de. Furthermore, the method is preferably used to coat numerous | Steel components at the same time, particularly preferably all | Steel components are formed identical to each other. In general, the steel com- ; ponenten preferably at least one thread and particularly preferably | exactly one threaded steel component. The steel components are preferred | favors bulk goods, in particular filigree bulk goods, and preferably Ver- | binding means, such as screws, clamping sleeves, bags, and / or - electrical connection elements or parts thereof, such as components of a | terminal block. The steel components are also preferably components for | Screw-clamping sleeve connections. The steel components can be any | Have bige function, the steel components are preferably used to set a: nes electrical conductors are provided. The requirements for the upper | surface of the coated steel component, in particular to a zinc and/or | a passivation layer, on the one hand good anti-corrosion properties and ; on the other hand, a constant coefficient of friction with repeated tightening. | For this purpose at least part of the surface and preferably on the | Zinc coating applied to the entire surface of the steel components. | According to the invention, this application takes place in a galvanic deposition process ren, i.e. by electroplating. All processes for | understood electrochemical deposition of metals on the metallic surface of the L steel components using an electrolyte, wherein the. Electrolyte preferably an electrically conductive liquid, in particular an aqueous | saline solution is. >0 Preference is given to applying a pure zinc layer by galvanic deposition. de-process, i.e. a pure zinc coating, whereby the pure zinc layer is particularly | preferably no more than 1% of other metal atoms, except where appropriate from | surface of the steel component contains diffused metal atoms, while | other substances, especially polymers from the deposition process, in the. Zinc layer may be embedded. In particular, the |

Zinc layer using a pure and/or an iron- and/or aluminum-free zinc electrolyte. | The galvanic application of the zinc layer can be both heating the.

- Steel component and / or the plating bath or without a setting. adjustment of the temperature. In general, however, the application takes place without a heating | zen above 420 °C, preferably without heating above 100 °C and more preferably | without heating over 50 °C. Also preferably, there is no heating of the | Steel components between electroplating and heat treatment to .

Forming of the intermetallic zinc-iron phases instead, . The zinc coating is basically a flat zinc layer | on the surface of the steel component, with the zinc coating preferably completely covering the surface of the steel component and in particular preferably | closes completely so that no oxygen and/or liquid can reach the | surface of the steel component. Under a friction-optimized | Zinc coating means a coating of zinc or a zinc alloy | the characteristic | has properties and in particular a particularly low, one at | repeated suit that changes particularly slightly and/or a particularly . has a constant coefficient of friction or coefficient of friction. In particular, | at least the outer or surface of the zinc layer is designed in such a way that | an optimized coefficient of friction or coefficient of friction results. .

The heat treatment can initially be designed as desired and in particular a | have any temperature profile. The heat treatment is preferably carried out | by heating to a set temperature, holding for a duration of | this temperature and subsequent cooling. Such a heating cycle becomes | preferably carried out only once, although repeated repetition is fundamentally possible. Furthermore, the heating is preferably carried out uniformly. and/or continuously up to the specified temperature. Cooling also takes place. preferably uninterrupted and particularly preferably except for the |

Initial temperature before heat treatment. The heat treatment also takes place action in air or in a gas atmosphere, i.e. outside of a liquid. | The heat treatment is particularly preferably carried out within an oven, in particular | other within an electric furnace. For this purpose, the steel com- | component preferably introduced into a corresponding oven. In particular, the | Heat treatment An anneal at a specified temperature. The heat treatment is particularly preferably carried out starting from a temperature below | 100° C., very particularly preferably below 50° C. and particularly preferably starting from room temperature. | According to the invention, the heat treatment is carried out on the solid, i.e. below the | Melting temperature of zinc around 420 °C. This leads to diffusion processes in the | Solid for the formation, stabilization and / or expression of the desired in | termetallic zinc-iron phases. Generally applies to the temperature range.

the heat treatment, which is preferably between 200° C. and 420° C., particularly | preferably between 230°C and 420°C and most preferably between 250°.

and 400 ° C is that the formation, stabilization and / or expression of ge. desired intermetallic zinc-iron phases occurs the faster, the higher | the temperature is .

; The inventive formation of one or more different intermetallic | Zinc-iron phases also include stabilizing and/or shaping and/or changing zinc phases that have already occurred during the galvanic deposition process iron phases. However, it is preferred by the heat treatment at least.

an intermetallic zinc-iron phase formed, which was previously not or only to a. very small or significantly lower proportion was present. The heat treatment particularly preferably serves to optimize the layer structure of the zinc coating; tion and in particular the layers of intermetallic zinc contained therein. iron phases. The heat treatment for forming | several, superimposed, merging layers and/or for | Stabilizing and shaping these layers. |

LU101954 ; According to the invention by means of the heat treatment at least one intermetallic | cal zinc-iron phase is formed, with preferably at the same time, in particular on the surface of the zinc coating, a layer of pure zinc, i.e. an n-phase | is present which contains elements other than zinc only in the form of unavoidable impurities | ments and necessary auxiliary materials. In addition, there are usually next to | of the specifically formed intermetallic zinc-iron phases further interme- | metallic zinc-iron phases in small proportions. | Depending on the temperature and the holding time of the heat treatment, intermetallic zinc-iron phases with different stoichiometry are generally formed, with the stoichiometry having a direct influence on the properties and in particular the hardness of the deposited zinc layer and thus also directly | indirectly influences the resistance to wear and/or the coefficient of friction. Thereby exist | numerous different intermetallic zinc-iron phases, but only | some of crucial importance with regard to corrosion protection and friction | valuable properties of a galvanically produced zinc coating on a steel . component are. For example, in the case of galvanized steel components, | a face-centered cubic M-phase, which is characterized by a brittle material behavior. is marked. In addition, an iron-poor hexagonal 5-phase can arise, which ; through very ductile properties and when appearing in a closed layer through ; characterized by high corrosion resistance. The € phase with a monoclinic Ë crystal structure develops in the form of a brittle palisade layer. The Eisengeh- | alt in this compound is lower than in the previously presented intermetallic , phases. The pure zinc (n-phase) contains no iron atoms and has the lowest | Hardness. However, the iron mass fraction in the intermetallic zinc egg | sen phases within the zinc coating of the steel component prefer not | more than 10%, more preferably not more than 7.5% and most preferably | preferably no more than 6%. .

Under the optimization of the coefficient of friction, a reduction in the initial | lichen coefficient of friction, especially when a first actuation or use of the | steel component, and/or a reduction in the increase in the coefficient of friction at | subsequent operations or uses of the steel component. | Alternatively or additionally, the optimization can also include that the coefficient of friction.

is kept low and/or constant for as long as possible in the event of repeated actuation or use of the steel component. In particular, however, | is also optimal a reduction in the coefficient of friction with repeated actuation or use of the . steel component. .

In a preferred embodiment of the inventive method for the manufacture. If a friction-optimized zinc coating is applied, a zinc coating is applied.

layer and all subsequent process steps for producing the zinc coating; layered steel component at temperatures below 420 °C, resulting in . advantageously a melting of the zinc and thus an undesirable phase. transformation as well as unfavorable material movement on the surface of the . Steel component can be avoided in a simple manner. Especially preferred.

a temperature of 400 °C is not exceeded. | According to an advantageous development of the inventive method for. The holding time of the heating | treatment between 10 minutes and 10 hours, preferably between 20 minutes; ten and 6 hours and more preferably between 30 minutes and 4 hours, 'which results in a good and extensive formation of intermetallic zinc-iron phases. can be reached. The holding time is the duration of the heat treatment, where | of the zinc-coated steel component at an elevated temperature, in particular | special is kept at the maximum temperature of the heat treatment. Total | The layer thickness as well as the iron content in the zinc layer can be determined by a ; Controlling the variation of the hold time and/or the temperature, with an increasing hold time leading to greater diffusion of iron into the zinc layer and thus to a | increased iron content. The heat treatment is preferably carried out in one passage | continuous furnace, particularly preferred for a heat treatment of numerous steel com- | ponents, especially bulk material parts, at the same time. Alternatively, the heat treatment | However, treatment can also be carried out in a chamber furnace. |

The duration of the heat treatment depends, among other things, on the number of | treated steel components, with numerous | richer parts at the same time, for example in a lattice box or crate, a longer Ë duration of the heat treatment is preferred to ensure that internal lying parts have been heated for a sufficient period of time.

Accordingly, a É heat treatment of individual steel components or individually arranged | Steel components are made significantly shorter.

With regard to the duration of the heat treatment, it still applies that the longer the duration, the better the reproducibility | bility of the desired result, especially over all simultaneously heated steel )

components can be achieved. | The minimum holding time is preferably, in particular at a temperature of |

300° C., at least 15 minutes and particularly preferably 20 minutes, since at a temperature of 300° C. and for a period of 10 minutes there is still no measurable egg:

senddiffusion can be detected.

The maximum holding time is generally not | limited, but with increasing time no significant changes | gen more can be observed, so that a holding time of a maximum of 4 hours | makes sense and particularly prefers the holding time of less than 3 hours and very particularly | that is preferably less than 2 hours.

Even with a hold time of 10 hours at ;

300 °C, a maximum iron mass content of 6% was measured in the zinc layer | will.

Î

Specifically, to form {-phase (zeta phase) of iron-zinc, to stabilize | and/or pronounced, due to which particularly good coefficients of friction of the zinc-coated steel component can be achieved, sees a possible embodiment | of the inventive method that the heat treatment at a temperature | temperature between 220 °C and 330 °C, preferably between 230 °C and 320 °C, especially | Ders preferably between 250 ° C and 310 ° C and very particularly preferably at |

300 °C.

The Z-phase has a significant influence on the constancy | the coefficient of friction, especially if the steel component is tightened several times. | The heat treatment for forming, stabilizing and/or shaping is preferably carried out gene of the {-phase at a temperature of 300 °C for a holding time between |

LU101954 À -10- .

30 minutes and 2 hours, particularly preferably between 45 minutes and 1.5 hours | den and most preferably 1 hour. At the same time, it can also form, . Stabilizing and/or expressing a 5-phase (delta phase) of the iron-zinc to- | occur in addition to the {-phase, which is even preferred in some cases. .

The à phase, which is particularly ductile and has a particularly good corrosion | protection of the zinc-coated steel component, but can alternatively or ; Completely also specifically by a heat treatment at a temperature between | 310° C. and 390° C., preferably between 330° C. and 370° C., particularly preferred.

between 340 °C and 360 °C and most preferably at 350 °C | the. In particular, a multi-step heat treatment is also conceivable, | in particular initially for forming, stabilizing and/or expressing the {-phase | and subsequently at higher temperature for forming, stabilizing and/or expressing.

gene of the ö-phase. Alternatively, an δ phase can also be formed first and .

then heat treatment to form the {-phase. | Ideally, the hold time to form, stabilize and/or express the :5 phase at a temperature of 350°C is between 1 hour and 3 hours, be- | particularly preferably between 1.5 hours and 2.5 hours and very particularly be-.

preferably 2 hours. In particular at lower temperatures, a longer holding time is also sensible. | If, on the other hand, a heat treatment is carried out at significantly higher temperatures, in particular | Especially just below the melting point of zinc, a [-phase A (gamma phase) of the iron-zinc is thereby formed, stabilized and/or pronounced. A sol- | Che heat treatment is preferably carried out at at least 390 ° C, particularly preferably | at least 400°C and most preferably at least 410°C, | again preferably the maximum temperature is 420°C. This heat treatment | ment is further preferably carried out over a long period of at least 3 hours, | more preferably of at least 4 hours and most preferably of | at least 5 hours. |

The surface of the steel component can be treated before the zinc layer is applied be lovingly pre-treated. The pretreatment is particularly preferably | for conditioning the surface of the steel component. For example, this can be | cleaning, in particular degreasing, of the surface. Grinding or chemical removal of oxide layers is also conceivable. Furthermore- | from the surface of the steel component before applying the zinc layer | can also be pickled and/or pre-galvanised. The pickling can be done in any | Way, for example by dip pickling, spray pickling, rotary pickling and / or | electrochemical pickling done. | | In a preferred development of the method according to the invention for producing | place a friction-optimized zinc coating on a steel component.

prior to applying the zinc layer to the surface of the steel component in the ; galvanic deposition process and / or after pickling and / or after.

pre-galvanizing, a heat treatment against possible hydrogen embrittlement is carried out, preferably at temperatures between 200 °C and 250 °C. | This heat treatment is in particular a aging against hydrogen embrittlement, in which the hydrogen diffuses out of the steel component diet and/or is distributed more evenly in the material, whereby the hydrogen loss | - brittleness is at least significantly reduced or even completely avoided or reduced can be lifted. Also preferably, immediately after this heat treatment, in particular after aging, the finished galvanizing takes place in the galvanic deposition process. In this case, such a heat treatment and in particular an Î aging in the case of heavily hardened steel base materials of the steel component is required particularly useful. | In order to achieve even better corrosion protection and in particular protection of the zinc | layer against wear and to protect the pure zinc on the surface from oxidation | of the zinc-coated steel component and an even better | Optimizing the coefficient of friction is preferably done after applying the zinc | layer on the surface of the steel component in the electroplating | process a conditioning of the zinc surface, in particular by a |

Passivation of the zinc surface, with preference being given to passivation by means of an organo-ceramic coating or by means of at least one, preferably several organo-. noceramic layers.

The passivation is preferably carried out by a | immerse in a passivating agent.

The organo-ceramic layers are also preferably formed predominantly from chromium and/or zinc oxides. . A preferred embodiment of the method according to the invention for producing | a friction-optimized zinc coating provides that the heat treatment ;

to form the zinc-iron phases when using a temperature-resistant :

Passivation layer after the passivation or subsequent to the passivation Ë takes place.

To do this, the passivation layer must at least reach the maximum temperature | temperature of the heat treatment, preferably up to at least 10° C. and particularly preferably | must be at least 20 °C above the maximum heat treatment temperature.

The heat treatment is particularly preferably carried out for |

Formation of the zinc-iron phases as the last manufacturing step of the zinc-coated | steel components.

Passivation immediately after the | is also preferred Application of the zinc layer to the surface of the steel component in the galvanic 'nical deposition process made to the newly formed zinc layer | to protect it from oxidation as quickly as possible.

In the case of a non-temperature-resistant | ended passivation layer must be heat treated accordingly before the pass | take place.

According to a preferred development of the method according to the invention for producing a friction-optimized zinc coating, the application of the

— Zinc layer on the surface of the steel component in the electroplating | process using an alkaline zinc electrolyte, which preferably contains nitrogen | includes term polymers and / or is preferably cyanide-free.

The selection of the | zinc electrolyte used in galvanic deposition processes has an impact on | the coefficient of friction of the zinc-coated steel component, which is characterized in particular by | substances stored in the zinc layer, in particular organic substances. | It was found that weakly acidic electrolytes and/or electrolytes with | sulphur-containing surfactants are only suitable to a very limited extent, since there a sharp increase in the |

Friction value could be observed. | Several exemplary embodiments of the invention are described below with reference to a | drawing described in more detail.

In the figure shows: |

1 shows a schematic flowchart of a method for producing a | friction-optimized zinc coating on a steel component. |

In a first embodiment of the method for producing a friction-optimized l

Zinc coating on a steel component, a pure zinc coating is first Ë applied to the surface of a steel screw for an electrical terminal block | taken, which is done by means of a galvanic deposition process.

where | a cyanide-free, alkaline zinc electrolyte is used in an aqueous solution, with | the solution preferably also contains nitrogen-containing polymers.

The use :

this alkaline zinc electrolyte causes the nitrogenous polymers | are at least partially embedded in the zinc coating, whereby the steel: screw has significantly more stable coefficients of friction. |

A heat treatment is carried out immediately after the coating leads to the zinc-coated steel screw being heated in an oven at Ë 300 °C for 30 minutes to create a {-zinc-iron phase between the superficial, rei- | to form a zinc and steel surface of the coated steel screw and | to stabilize.

In this case, this optimized layer structure is characterized by | through the stabilization of the € phase in the transition area from the zinc layer to the |

base material.

The course of the coefficient of friction is characterized by an almost constant | characterizes the coefficient of friction over ten tightening cycles and also the scattering of the friction | values could be significantly reduced as a result. | Alternatively, the duration of the heat treatment can also be between 20 minutes and |

be 4 hours.

In any case, only one temperature cycle with a | individual heating, holding at 300 °C and cooling. |

Such a heat treatment to form a zinc-iron intermetallic phase |

-14- can be done in a continuous furnace, for example, with the steel screws being heated at a heating rate of about 10 K/min up to 300 °C and kept at this temperature for 30 minutes. This is followed by cooling in still air, in particular at a cooling rate of about 5 Kis.

In addition, however, a heat treatment is also possible exclusively at a lower temperature and for a longer period of time. For this purpose, for example, the steel screws are heated in a chamber furnace at a heating rate of about 10 K/min up to 250° C. to form an intermetallic zinc-iron phase and are kept at this temperature for about 6 hours to 10 hours or longer . This is followed by cooling in still air, in particular at a cooling rate of about 5 Kis. Particularly preferably, after the heat treatment at 300° C., there is no complete cooling, but rather the steel components are then kept at a temperature of 250° C. for a longer period, in particular 6 hours, as shown in FIG. This will give a smoother result across | all steel components as well as an undisturbed, more even layer structure each | of the steel component. | In a further embodiment, a steel component of an electrical contact element is galvanically coated using a cyanide-free, alkaline zinc electrolyte. Immediately afterwards, passivation is carried out, with organo-ceramic layers predominantly formed from chromium and/or zinc oxides being applied to the galvanized surface of the steel component.

Then, as the last manufacturing step of the steel component, the galvanized and passivated component is heat treated in an oven at a temperature of 300 °C for a period of 30 minutes. | 30 Another version is based on a component coated identically with zinc, with heat treatment taking place in two steps. The component is first heated to 350 °C and held there for 30 minutes. This will be in the following

LU101954 | Component cooled to 300 °C and held there for another hour. | After it has completely cooled down, passivation takes place, with a | not heat-resistant passivating agent can be done. .

Claims (10)

-16 - Claims 1. Method for producing a friction-optimized zinc coating on a steel component, with the steps: - applying a zinc layer to the surface of the steel component by means of a galvanic deposition process and subsequently - heat treatment at a temperature below 420 °C for the Targeted formation of intermetallic zinc-iron phases in the galvanically deposited zinc layer to optimize the coefficient of friction. 2. Method for producing a friction-optimized zinc coating on a steel component according to claim 1, characterized in that the application of a zinc layer and all subsequent method steps for producing the zinc-coated steel component take place at temperatures below 420 °C. 3. Method for producing a friction-optimized zinc coating on a steel component according to one of claims 1 or 2, characterized in that the holding time of the heat treatment is between 20 minutes and 10 hours, preferably between 20 minutes and 6 hours and particularly preferred is between 30 minutes and 4 hours. 4. A method for producing a friction-optimized zinc coating on a steel component according to at least one of the preceding claims, characterized in that the heat treatment is carried out at a temperature between 250 °C and 310 °C, whereby a {-phase of iron-zinc is formed. 5. A method for producing a friction-optimized zinc coating on a steel component according to at least one of the preceding claims, characterized in that the heat treatment is carried out at a temperature between 340° C. and 360° C., resulting in an oil phase of Iron I Ell, | zinc is formed. | 6. A method for producing a friction-optimized zinc coating on a à ner steel component according to at least one of the preceding claims | che, characterized in that the surface of the steel component before | is pickled and/or pre-galvanised before the zinc layer is applied. | 7. Process for producing a friction-optimized zinc coating on a | Ner steel component according to at least one of the preceding claims | che, characterized in that before the application of the zinc layer È and / or after the pickling and / or after the pre-galvanizing another. Heat treatment against possible hydrogen embrittlement. men, which takes place at temperatures between 200 °C and 250 °C. | 8. Process for producing a friction-optimized zinc coating on a |! Ner steel component according to at least one of the preceding claims. surface, characterized in that after the application of the zinc layer. + Passivation of the zinc surface with an organo-ceramic coating; he follows. E 9. Process for producing a friction-optimized zinc coating on a | Ner steel component according to at least one of the preceding claims | che, characterized in that the heat treatment for forming the | Zinc-iron phases when using a temperature-resistant passive | fourth layer takes place after the passivation. | 10. Method for producing a friction-optimized zinc coating on a | Ner steel component according to at least one of the preceding claims | che, characterized in that the application of the zinc layer on the | Surface of the steel component in the electroplating process | takes place by means of an alkaline zinc electrolyte, the nitrogen-containing poly-; more includes. |