EP0324394B1 - Process and agent for simultaneous vibratory grinding, cleaning and passivation of metallic workpieces - Google Patents

Abstract

The invention relates to a process and agent for the simultaneous vibratory grinding, cleaning and passivation of metallic workpieces using acidic aqueous solutions which contain orthophosphoric acid and/or pyrophosphoric acids and/or water-soluble salts thereof, oligocarboxylic acids and, if required, also surfactants, corrosion inhibitors and other customary active ingredients and/or auxiliaries.

Description

The invention relates to methods and means for simultaneous surface grinding, cleaning and passivating metallic workpieces.

Metallic workpieces or articles of daily use are now largely manufactured by means of industrial mass production in automated processes. The surfaces of such metal parts, which are made of steel, cast iron, copper and its alloys, aluminum and its alloys, zinc, magnesium and other metals, usually have to be subjected to a finishing process before they are sold directly, used as intended or further processed in known finishing processes will.

Metallic workpieces produced by turning, milling, casting or similar, metal-processing methods often have sharp cut edges or corners or also rough or surfaces covered with scale layers, so that deburring and rounding of the cut edges and corners, often also smoothing or polishing of the entire surface, is required. Especially in processes of further processing, the quality of subsequently applied surface layers on such workpieces depends to a large extent on how good the metallic surface is for the application of such additional, refining agents Layers is prepared. For example, the galvanic deposition of metals on such surfaces can only proceed satisfactorily if the galvanic deposition process has been preceded by cleaning, descaling and grinding of the surface.

Metal workpieces or molded parts can be processed either by manual mechanical deburring, grinding, sanding, brushing and polishing or by a mechanical-mechanical processing method. The purely manual mechanical processing of large quantities of metallic parts, especially small metallic parts, is hardly acceptable today for reasons of economy. The mechanical-chemical processing, e.g. the so-called "slide grinding" is a process that is carried out in bell apparatus, drum apparatus, vibration machines or centrifugal machines. The workpieces are brought into contact with natural (pebbles, dolomite, quartz, etc.) or synthetic (ceramic or plastic-bonded corundum, aluminum oxide, silicon carbide or boron carbide) grinding wheels of various shapes under spraying with water-based compositions specially developed for vibratory grinding. The size and external shape (triangles, cylinders, stars, cones, spheres, etc.) and the roughness of the grinding wheels ("chips") ensure that the metal surfaces are abraded, possibly also polished. Metallic workpieces and / or moldings can be descaled, deburred, ground, smoothed, polished and polished by such surface grinding.

The chemical treatment agents ("compounds") used in the course of the surface grinding are matched in their composition and their dosage to the metallic surfaces that are to be surface-finished, but must also take into account special features of the special vibratory finishing process. The main tasks of such treatment agents are to ensure good cleaning, dispersing and dirt-carrying capacity, so that oil and grease contamination are emulsified and the abrasion of the abrasive bodies and the workpieces is completely removed and is not deposited on the workpieces. In addition, the agents are intended to prevent corrosion of the metallic workpieces or molded parts and, moreover, to have a favorable influence on the grinding action and / or polishing action during slide grinding. For this it is necessary that the agents do not coat the molded parts with a lubricating layer during grinding, which prevent the gloss effect when polishing the molded parts. In addition, due to their composition, such abrasives can act on the grinding action of the chips, thereby making it possible to deburr and pre-grind the workpieces with the same chips and, after changing the chemical treatment agent, to carry out a fine treatment and polishing.

The agents are usually packaged in such a way that they can be concentrated in liquid form or metered in prediluted by means of automated pumps. Typically, such abrasives react neutral to weakly alkaline in water and contain combinations of washing-active and corrosion-inhibiting substances.

A disadvantage of the products known from the prior art and mostly developed purely empirically is that a differently adjusted agent had to be used for each application, ie each metallic material of the workpieces or molded parts. This necessitated a complete changeover of the vibratory finishing process when changing the workpieces to be machined using the vibratory finishing process. It was also disadvantageous that satisfactory results were only achieved with surface grinding could be achieved if the surfaces of the metallic workpieces or molded parts had been carefully cleaned and passivated before the surface grinding. Machining processes upstream of the actual vibratory grinding were therefore necessary in order to condition the metal surface in the desired shape. In addition to the fact that these upstream processing steps required separate systems and chemicals, the effect of the surface grinding agents and thus the success of the surface grinding method was regularly adversely affected by the fact that the cleaning agents and passivating agents were introduced into the equipment for surface grinding. As a result, the compounds were only able to develop their effects to a limited extent during surface grinding.

US-A-3 071 456 describes a method for barrel finishing of metal parts with the aid of grinding wheels. Aqueous formulations are used which contain phosphoric acid or phosphoric acid salts and / or nitro compounds or carboxylic acids, for example benzoic acid, toluic acid, gallic acid, acetic acid, citric acid or oxalic acid. These formulations result in the formation of a thin layer on the metal surfaces, which is rubbed off on the one hand by the mechanical treatment and on the other hand subsequently formed again. The formulations can also contain wetting agents, for example petroleum sulfonate, and oxidation inhibitors.

Furthermore, FR-A-1 423 822 relates to a method for polishing stainless steel metal surfaces by mechanical treatment. The formulations used here contain, in addition to grinding wheels, dilute acids, for example hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid or sulfonic acids, and surface-active substances.

Surprisingly, it has now been found that when powdery or liquid agents are used, it is possible to combine the individual process steps of surface grinding, cleaning and passivating in one process step by immersion or spraying process and to use only one agent for this which has a cleaning and passivating effect and also promotes the finishing process. This has made it possible to avoid the technical disadvantages of a three-step process using three differently composed solutions.

• (a) 0,2 bis 10 Gew.-% Alkalimetallsalze und/oder Ammoniumsalze der Orthophosphorsäure und/oder von Pyrophosphorsäuren,
• (b) 0,01 bis 1 Gew.-% Weinsäure und/oder Citronensäure,
• (c) 0,005 bis 2 Gew.-% eines oder mehrerer nichtionischer Tenside,
• (d) gegebenenfalls 0,001 bis 0,02 Gew.-% eines oder mehrerer Korrosionsinhibitoren und
• (e) gegebenenfalls 0,01 bis 0,2 Gew.-% weiterer, in Reinigungs-, Passivierungs- und Gleitschleifmitteln an sich üblicher Wirkstoffe und/oder Hilfsstoffe,

wobei die jeweils angegebenen Mengen auf den Aktivsubstanzgehalt in der Anwendungslösung bezogen sind.The invention relates to a method for simultaneous vibratory grinding, cleaning and passivation of metallic workpieces using acidic, aqueous solutions containing salts of phosphoric acids, carboxylic acids and wetting agents, which is characterized in that the workpieces with aqueous, a pH in the range of 1 up to 6 solutions that contain the following components:

• (a) 0.2 to 10% by weight of alkali metal salts and / or ammonium salts of orthophosphoric acid and / or pyrophosphoric acids,
• (b) 0.01 to 1% by weight of tartaric acid and / or citric acid,
• (c) 0.005 to 2% by weight of one or more nonionic surfactants,
• (d) optionally 0.001 to 0.02% by weight of one or more corrosion inhibitors and
• (e) optionally from 0.01 to 0.2% by weight of further active substances and / or auxiliaries which are customary per se in cleaning, passivating and surface grinding agents,

where the amounts specified are based on the active substance content in the application solution.

The invention also relates to means for simultaneous surface grinding, cleaning and passivating metallic workpieces.

The method according to the invention and the means used in this method for simultaneous surface grinding, cleaning and passivating metallic workpieces can be applied to metallic workpieces and / or molded parts of the most varied composition. So it is possible in the course of the process workpieces or molded parts made of iron and all tendon alloys, for example steels of different compositions, cast iron, etc., copper and its alloys, for example brass, bronze etc., aluminum alloys, zinc or magnesium or other metals or Treat alloys. The surprising thing about the present method is that not only the actual mechanical-chemical surface treatment of the surface grinding, which is usually carried out in drums or vibrators, can be carried out using these solutions. Rather, the usually upstream step of cleaning the metallic workpieces or molded parts and passivating the respective metallic surface is carried out with the same solutions in the same process without the need for additional systems or treatment solutions. The respective metallic surface is cleaned, descaled, passivated, deburred, ground, smoothed, polished and polished in one step.

For this purpose, according to the invention, the workpieces are brought into contact with aqueous solutions which have a pH in the range from 1 to 6. Solutions which have a pH in the range from 3.5 to 5 are preferably used. Depending on the system, contact with the workpieces or molded parts takes place by immersion or spraying. The aqueous solutions according to the invention are usually applied in the present process by spraying the workpieces or molded parts in the systems (drums, vibrators, etc.) in which they are moved together with the grinding wheels, with the aqueous solutions and these between the workpieces and run through the grinding wheels to the bottom of the respective system. The solutions are in contact with the grinding wheel surfaces and metallic surfaces. They also remove the dirt detached in the cleaning process and the metal particles and / or abrasive particles detached in the tumble grinding process, are freed of such contaminants after exiting the system and brought back into contact with the workpieces and molded parts.

In the process according to the invention, the workpieces and moldings are brought into contact with aqueous solutions which contain alkali metal salts and / or ammonium salts of orthophosphoric acid and / or pyrophosphoric acids as one of the essential components. "Pyrophosphoric acids" are understood to mean all those compounds which have formed by condensation of several phosphate groups on one another. The alkali metal salts are therefore the lithium salts, sodium salts, potassium salts, rubidium salts or cesium salts, of which the potassium salts and particularly the sodium salts are preferred because of their ready availability are. As ammonium salts, both those with an NH₄⁺ cation and also those ammonium salts which carry one or more organic substituents on the nitrogen atom can be used. Of such organoammonium compounds, those which carry one or more alkyl radicals with a straight-chain or branched chain and 1 to 6 carbon atoms in the alkyl radical are particularly preferred. Of the ammonium salts, the NH₄⁺ salts are particularly preferred and can advantageously be used as phosphate components in the aqueous solutions which are used in the process according to the invention.

In the process according to the invention, the workpieces are brought into contact with acidic aqueous solutions which contain one or more of the phosphate components mentioned in amounts of 0.2 to 10% by weight. The weight data are based on the finished application solution and indicate the active substance content which is used in such application solutions.

The inventive method for simultaneous surface grinding, cleaning and passivating metallic workpieces is further characterized in that the workpieces or molded parts are brought into contact with aqueous solutions which contain tartaric acid or citric acid or mixtures of these two carboxylic acids as a further essential component.

According to the invention, such aqueous solutions for simultaneous vibratory grinding, for cleaning and passivation of metallic workpieces are used which contain the carboxylic acid components mentioned in amounts of 0.01 to 1% by weight. As in the case of the phosphate components, this is also based on the active substance content in the finished application solutions.

Another component of the aqueous solutions used in the process according to the invention are nonionic surfactants, it also being possible here for the aqueous solutions to contain one or more surfactants as surface-active components. The total amounts of surfactants contained in the aqueous solutions used are in the range from 0.005 to 2% by weight, according to the process of the invention. This information also relates to the active substance content in the application solution.

The process also provides that the aqueous treatment solutions optionally contain one or more corrosion inhibitors. Corrosion inhibitors of this type are to be matched to the metal from which the metallic workpieces or molded parts are made, which are to be cleaned, passivated and, at the same time, subjected to vibratory grinding according to the inventive method. Aqueous solutions are preferably used in which one or more compounds from the group of alkali metal molybdates, preferably sodium molybdates, benzotriazole, tolyltriazole and benzothiazole, are used as corrosion inhibitor components. Such corrosion inhibitors, which, like the other components, can be used alone or in combination of several components acting in the same direction, are present in amounts of 0.001 to 0.02% by weight. As with the other components, this information is based on the active substance content in the application solution.

The process can be carried out using such acidic aqueous solutions which, in addition to the components described generally or in more detail above, also contain other active substances and / or auxiliaries which are customary per se. Such active ingredients can be, for example, water hardness stabilizers. Their use is particularly advantageous if the treatment agents were mixed with water in the process, which contains large amounts of hardness formers, in particular alkaline earth metal carbonates. Such water hardness stabilizers are, for example, phosphonic acids, such as, for example, hydroxyethane diphosphonic acid (HEDP) or phosphonobutane tricarboxylic acid (PBTC), or their water-soluble salts, but also ethylenediaminetetraacetic acid or its water-soluble salts, nitrilotriacetic acid and its water-soluble salts or else for such purposes from the Connections known in the art. If their co-use is desired, these are present in amounts of 0.01 to 0.2% by weight and allow the use of "hard" water in the process according to the invention.

As already described above, in the process according to the invention, such aqueous solutions are usually brought into contact with the metallic workpieces or molded parts by dipping or spraying. This involves simultaneous surface grinding, cleaning and passivating the surfaces of the workpieces. This is usually carried out at temperatures in the range from 20 to 60 ° C., but preferably at room temperature. The treatment times depend very much on the degree of soiling, the thickness of the burrs or protrusions to be removed, the hardness, size and shape of the abrasive bodies and also on the properties of the aqueous treatment solutions. In preferred embodiments of the method, they are in the range between 10 and 60 minutes. Usually the surface treatment is followed only by a drying process. This drying process can be carried out using conventional aids, such as, for example, maize meal, wood flour, etc., at room temperature using the drum method or using warm air. In special cases, however, a rinse can also be provided before the drying process. This essentially depends on the type of further treatment of the workpieces or molded parts treated according to the method according to the invention.

The invention also includes the means used in the method described in more detail above for simultaneous surface grinding, cleaning and passivating metallic workpieces or molded parts. The agents can either be packaged in powder form and packaged as such and stirred into water at the application site with little effort, or they are prepared in the form of highly concentrated aqueous solutions and merely diluted at the application site. The former has the advantage that only the pure substance is transported, thus avoiding unnecessary water transport. However, the latter is more advantageous because liquid concentrates can be metered in automatically at the application site by means of metering pumps and thus make handling easier for the user. The aqueous solutions which come on the market in the form of concentrates are homogeneous. Due to the components they contain, aqueous concentrates have a pH in the range from 1 to 6. The pH value is preferably in the range from 3.5 to 5. However, if the pH value is not in this range due to the use of more alkaline components, it can optionally be added by adding non-corrosive acids, preferably for example phosphoric acids, phosphonic acids, phosphonocarboxylic acids or Carboxylic acids. However, a pH adjustment is usually not necessary. The aqueous application solutions are usually used with an active substance content in the range from approximately 0.2 to approximately 14% by weight.

The agents according to the invention for simultaneous surface grinding, cleaning and passivating metallic workpieces contain, as phosphate components, alkali metal salts and / or ammonium salts of orthophosphoric acid and / or pyrophosphoric acids. Preferred phosphate components in the agents according to the invention are acidic sodium phosphates and / or sodium pyrophosphates. Other essential components of the agents according to the invention are tartaric acid and / or citric acid.

Another component of the agents according to the invention are nonionic surfactants. These can also be represented as individual compounds or in a mixture of several surfactants.

R'

einen geradkettigen oder verzweigten Alkylrest mit 8 bis 18 C-Atomen,

R''

einen Alkylrest mit 4 bis 8 C-Atomen,

m

eine Zahl von 2 bis 4 und

n

eine Zahl von 7 bis 12 bedeuten.

A large number of compounds known per se from the prior art as surfactants are suitable as surfactants for the agents according to the invention. For example, addition products of ethylene oxide and / or propylene oxide to fatty alcohols or fatty amines, ie alcohols and / or, are used as nonionic surfactants Amines which carry 6 to 18 carbon atoms in the straight-chain or branched-chain alkyl radical. Polyalkylene glycol ethers of the following general formula are also suitable as nonionic surfactants



R'-O - [(CH₂) _m -O] _n -R ''



in the

R '

a straight-chain or branched alkyl radical having 8 to 18 carbon atoms,

R ''

an alkyl radical with 4 to 8 carbon atoms,

m

a number from 2 to 4 and

n

represent a number from 7 to 12.

Such polyalkylene glycol ethers are known as weakly foaming nonionic surfactants, in some cases even as pronounced defoamers, and are therefore particularly suitable.

The agents according to the invention can optionally also contain one or more corrosion inhibitors. These are usually matched to the respective specific application problem and are thus geared towards the metallic surfaces that are to be cleaned, passivated and slip-treated. Suitable corrosion inhibitors can also be used with one another, which has the advantage that the agents according to the invention can thereby be used for a larger number of applications. Compounds from the group alkali metal molybdates, preferably sodium molybdates, benzotriazole, tolyltriazole and benzothiazole, are preferably used as corrosion inhibitors.

In addition, the agents according to the invention can also contain other active substances and / or auxiliaries which are customary in cleaning, passivating and slide grinding agents. Such additional active ingredients, which are also used in preferred embodiments of the agents according to the invention, are water hardness stabilizers. As such, individual compounds or combinations from the group of the phosphonic acids, such as, for example, hydroxyethyldiphosphonic acid, phosphonobutane tricarboxylic acid, or their water-soluble salts, ethylenediaminetetraacetic acid and their salts and nitrilotriacetic acid and their water-soluble salts can be used.

As already explained in more detail above, the agents according to the invention can be used as powder, i.e. as 100% active substance or as concentrates.

• (a) Alkalimetallsalze und/oder Ammoniumsalze der Orthophosphorsäure und/oder von Pyrophosphorsäuren in Mengen von 50 bis 98 Gew.-%,
• (b) Weinsäure und/oder Citronensäure in Mengen von 1 bis 10 Gew.-%,
• (c) ein oder mehrere nichtionische(s) Tensid(e) in Mengen von 0,1 bis 20 Gew.-%,
• (d) gegebenenfalls einen oder mehrere Korrosionsinhibitor(en) in Mengen von 0,01 bis 0,5 Gew.-% und
• (e) gegebenenfalls weitere, in Reinigungs-, Passivierungs- und Gleitschleifmitteln an sich übliche Wirkstoffe und/oder Hilfsstoffe in Mengen von 1 bis 20 Gew.-%.

In a preferred embodiment of the invention, the agents according to the invention are in the form of a powder containing salts of phosphoric acids, carboxylic acids and wetting agents, and also:

• (a) alkali metal salts and / or ammonium salts of orthophosphoric acid and / or pyrophosphoric acids in amounts of 50 to 98% by weight,
• (b) tartaric acid and / or citric acid in amounts of 1 to 10% by weight,
• (c) one or more nonionic surfactant (s) in amounts of 0.1 to 20% by weight,
• (d) optionally one or more corrosion inhibitor (s) in amounts of 0.01 to 0.5% by weight and
• (e) if appropriate, further active ingredients and / or auxiliaries which are customary per se in cleaning, passivating and vibratory abrasives in amounts of 1 to 20% by weight.

• (a) Alkalimetallsalze und/oder Ammoniumsalze der Orthophosphorsäure und/oder von Pyrophosphorsäuren in Mengen von 10 bis 50 Gew.-%,
• (b) Weinsäure und/oder Citronensäure in Mengen von 0,5 bis 5 Gew.-%,
• (c) ein oder mehrere nichtionische(s) Tensid(e) in Mengen von 0,2 bis 10 Gew.-%,
• (d) gegebenenfalls einen oder mehrere Korrosionsinhibitor(en) in Mengen von 0,01 bis 0,1 Gew.-%,
• (e) gegebenenfalls weitere, in Reinigungs-, Passivierungs- und Gleitschleifmitteln an sich übliche Wirkstoffe und/oder Hilfsstoffe in Mengen von 0,05 bis 1 Gew.-% und
• (f) Wasser in Mengen, die die Gesamtmengen der Komponenten (a) bis (e) zu 100 Gew.-% aufsummieren.

In a further, likewise preferred embodiment of the invention, the compositions according to the invention are present as aqueous concentrates, ie that such concentrates also contain water to the active substances, which adds up to 100% by weight of the total amount of all components. These aqueous concentrates contain salts of phosphoric acids, carboxylic acids and wetting agents, as well as:

• (a) alkali metal salts and / or ammonium salts of orthophosphoric acid and / or pyrophosphoric acids in amounts of 10 to 50% by weight,
• (b) tartaric acid and / or citric acid in amounts of 0.5 to 5% by weight,
• (c) one or more nonionic surfactant (s) in amounts of 0.2 to 10% by weight,
• (d) optionally one or more corrosion inhibitor (s) in amounts of 0.01 to 0.1% by weight,
• (e) optionally further active ingredients and / or auxiliaries which are customary per se in cleaning, passivating and vibratory abrasives in amounts of 0.05 to 1% by weight and
• (f) water in amounts which add up to 100% by weight of the total amounts of components (a) to (e).

Such concentrates are then diluted with additional water at the application site or the powdered products are dissolved in water. As already explained above, the application solutions have an active substance content in the range from approximately 0.2 to approximately 14% by weight. The total amounts of the components specified above in detail are thus mixed with an amount of water which adds up to 100% by weight of the total amount of all components. Depending on the individual components used, pH values are usually in the range from 1 to 6, preferably from 3.5 to 5. If, in the application solutions according to the invention, this pH value is not achieved solely by the specified components, further acids can optionally be added. However, these acids must not be corrosive and preferably come from the group of phosphoric acids, phosphonic acids, phosphonocarboxylic acids and carboxylic acids.

The invention is illustrated by the following example.

Workpieces or molded parts made of iron, brass, aluminum alloys with the composition AlSi₁₇Cu₄Mg (silumin), bronze, copper, a magnesium alloy with the composition MgMn₂ and Zinc was taken directly from production and cleaned, surface passivated and ground in a single operation in a vibration system using various grinding media (ceramic, plastic-bonded corundum) with the addition of the test solutions described below in the examples. After the one-step surface treatment, the workpieces were partially rinsed with tap water (approx. 15 ° d) and dried with corn grist or warm air (100 ° C). The surfaces were then assessed visually.

example 1

An application solution with the following composition was used:
98% H₂O;
0.63% Na₂H₂P₂O₇;
1.17% NaH₂PO₄;
0.08% citric acid;
0.06% of an adduct of 12 moles of ethylene oxide (EO) with coconut amine;
0.06% of a C₁₂ to C₁₈ fatty alcohol 9.1 EO-butyl ether.

The metal parts were degreased, passivated and deburred at 20 ° C. for 20 minutes under the action of this solution, which had a pH of 3.5. The result of this one-step process showed that very good degreasing and passivation had taken place and that the production-related metal burrs had been completely removed. The steel parts showed a bluish-iridescent passivation layer. The surfaces of the non-ferrous metals were, without exception, bare and smooth and showed no corrosion or contact points.

Even after storage for several weeks in medium humidity, corrosion on the metallic surfaces could not be determined.

At this point, it should be emphasized again that the present process is a one-step process in which, in a practical operation, both degreased and deoxidized / passivated, as well as deburring in vibratory grinding, are possible.

Claims (10)

1. A process for the simultaneous slide grinding, cleaning and passivation of metal workpieces using acidic aqueous solutions containing salts of phosphorus acids, carboxylic acids and wetting agents, characterized in that the workpieces are brought into contact with aqueous solutions which have a pH value in the range from 1 to 6 and which contain the following components:

   (a) 0.2 to 10% by weight alkali metal salts and/or ammonium salts of orthophosphoric acid and/or of pyrophosphoric acids,

   (b) 0.01 to 1% by weight tartaric acid and/or citric acid,

   (c) 0.005 to 2% by weight of one or more nonionic surfactants,

   (d) optionally 0. 001 to 0.02 by weight of one or more corrosion inhibitors and

   (e) optionally 0.01 to 0.2% by weight of other active substances and/or auxiliaries typically present in cleaning, passivating and slide grinding preparations,

   based in each case on the active substance content of the in-use solution.
2. A process as claimed in claim 1, characterized in that the aqueous solutions have a pH value of 3.5 to 5.
3. A process as claimed in claim 1 or 2, characterized in that acidic sodium phosphates and/or sodium pyrophosphates are used as the phosphate component (a).
4. A process as claimed in one or more of claims 1 to 3, characterized in that one or more compounds selected from alkali metal molybdates, benzotriazole tolyl triazole and benthiazole is/are used as the corrosion inhibitor component (d).
5. A process as claimed in one or more of claims 1 to 3, characterized in that water hardness stabilizers selected from phosphonic acids, ethylenediaminetetraacetic acid, nitrilotriacetic acid and water-soluble salts of these acids are used as additional active substance components (e).
6. Powder-form compounds for the simultaneous slide grinding, cleaning and passivation of metal workpieces containing salts of phosphorus acids, carboxylic acids and wetting agents, characterized in that they contain the following components:

   (a) alkali metal salts and/or ammonium salts of orthophosphoric acid and/or of pyrophosphoric acids in quantities of 50 to 98% by weight,

   (b) tartaric acid and/or citric acid in quantities of 1 to 10% by weight,

   (c) one or more nonionic surfactant(s) in quantities of 0.1 to 20% by weight,

   (d) optionally one or more corrosion inhibitor(s) in quantities of 0.01 to 0.5% by weight and

   (e) optionally other active substances and/or auxiliaries known per se for slide grinding, cleaning and passivating compounds in quantities of 1 to 20% by weight.
7. Liquid compounds for the simultaneous slide grinding, cleaning and passivation of metal workpieces containing salts of phosphorus acids, carboxylic acids and wetting agents, characterized in that they contain the following components:

   (a) alkali metal salts and/or ammonium salts of orthophosphoric acid and/or of pyrophosphoric acids in quantities of 10 to 50% by weight,

   (b) tartaric acid and/or citric acid in quantities of 0.5 to 5% by weight,

   (c) one or more nonionic surfactant(s) in quantities of 0.2 to 10% by weight,

   (d) optionally one or more corrosion inhibitor(s) in quantities of 0.01 to 0.1% by weight,

   (e) optionally other active substances and/or auxiliaries known per se for slide grinding, cleaning and passivating compounds in quantities of 0.05 to 1% by weight

   (f) water in quantities which balance the quantities of components (a) to (e) mentioned above to 100% by weight.
8. Compounds as claimed in claim 6 or 7, characterized in that they contain acidic sodium phosphates and/or sodium pyrophosphates as the phosphate component (a).
9. Compounds as claimed in claim 6 or 7, characterized in that they contain one or more compounds selected from alkali metal molybdates, benzotriazole, tolyl triazole and benzthiazole as the corrosion inhibitor component (d).
10. Compounds as claimed in claim 6 to 7, characterized in that they contain water hardness stabilizers selected from phosphonic acids, ethylenediaminetetraacetic acid, nitrilotriacetic acid and water-soluble salts of these acids as additional active substance components (e).