DE102009061274B3 - Process for coating a substrate, in which a wire-shaped spray material is melted in an arc and deposited as a layer on the substrate, as well as a wire-shaped spray material for arc wire spraying and a wire arc sprayed layer - Google Patents

Abstract

Method for coating a substrate (1), in which a wire-shaped spray material (4) is melted in an arc (5) and deposited as a layer (2) on the substrate (1), so that in the layer (2) after deposition martensite, bainite and perlite are formed during solidification, a spray material being used which essentially comprises iron, the spray material (4) being formed at least with carbon as a micro-alloy in such a way that martensite, bainite and pearlite are formed when the spray material solidifies, with Solid lubricant components or alloy components for the formation of solid lubricant components are provided in the micro-alloy, characterized in that the following alloy components are contained in the spray material used: - carbon: 0.1% by weight to 0.28% by weight, - manganese: 1 , 4% by weight to 2.1% by weight, - silicon: 0.05% by weight to 0.3% by weight., - copper: 0.05% by weight to 0.25% by weight .-% each based on a total tweight.

Description

The invention relates to a method for coating a substrate, in which a wire-shaped spray material is melted in an arc and deposited as a layer on the substrate and a wire-shaped spray material for arc wire spraying and a Lichtbogendrahtgespritze layer.

For reasons of energy efficiency and emission reduction, the lowest possible friction and high abrasion and wear resistance are aimed at in the production of internal combustion engines. For this purpose, engine components, such as cylinder bores or their walls are provided with a tread layer or it liners are inserted into the cylinder bores, which are provided with a tread layer. The application of such tread layers mostly takes place by means of thermal spraying, for example electric arc wire spraying. In arc wire spraying, an electric arc is generated by applying a voltage between two wire-shaped spray materials. In this case, the wire tips melt and are conveyed, for example, by means of a nebulizer gas to the surface to be coated, for example, the cylinder wall, where they accumulate.

From the DE 103 08 563 B3 a cylinder liner for internal combustion engines is known, comprising a base body with a wear protection coating on the tread, based on a hard iron alloy with carbon and oxygen, wherein the wear protection layer has martensitic phases and oxides and the wear protection layer in the arc-wire spraying process is applicable and the alloy of the coating has a carbon content of 0.05 to 3 wt .-%.

From the DE 20 2008 009 961 U1 is a wire-shaped spray material, in particular for arc wire spraying, comprising substantially iron, known, which is characterized in that the spray material is formed at least with carbon as a micro-alloy such that bainite and martensite arise during the solidification of the spray material. In the spray material, inter alia, 0.23 wt .-% to 0.4 wt .-% carbon, 1.4 wt .-% to 1.9 wt .-% manganese and 0.7 wt .-% to 0.98 wt .-% silicon included.

From the DE 20 2008 009 962 U1 is a wire-shaped spray material, in particular for arc wire spraying, comprising substantially iron, known, which is characterized in that the spray material is formed at least with carbon as a micro-alloy such that bainite and martensite arise during the solidification of the spray material. In the spray material are, inter alia, 0.8 wt .-% to 1.0 wt .-% carbon, 0.25 wt .-% to 0.45 wt .-% manganese and 0.25 wt .-% to 0.3 wt .-% silicon included.

From the DE 20 2008 009 963 U1 is a wire-shaped spray material, in particular for arc wire spraying, comprising substantially iron, known, which is characterized in that the spray material is formed at least with carbon as a micro-alloy such that bainite and martensite arise during the solidification of the spray material. In the spray material are, inter alia, 0.45 wt .-% to 0.55 wt .-% carbon, 1.4 wt .-% to 1.6 wt .-% manganese and 0.4 wt .-% to 0.65 wt .-% silicon included.

From the DE 20 2008 009 964 U1 is a wire-shaped spray material, in particular for arc wire spraying, comprising essentially iron, which is characterized in that the spray material is formed at least with carbon as a micro-alloy such that arise during solidification of the spray martensite, bainite and lower proportion of finely stripped perlite, wherein the microalloy solid lubricant constituents or alloy constituents are provided for the formation of solid lubricant constituents. In the spray material include 0.55 wt .-% to 0.65 wt .-% carbon, 0.7 wt .-% to 1.1 wt .-% manganese and 0.1 wt .-% to 0.4 wt .-% silicon included.

From the DE 20 2008 009 966 U1 is a wire-shaped spray material, in particular for arc wire spraying, comprising substantially iron, known, which is characterized in that the spray material is formed at least with carbon as a micro-alloy such that bainite and martensite arise during the solidification of the spray material. In the spray material are, inter alia, 0.35 wt .-% to 0.55 wt .-% carbon, 0.7 wt .-% to 0.9 wt .-% manganese and 0.15 wt .-% to 0.25 wt .-% silicon included.

It is an object of the invention to provide an improved method for arc wire spraying and a cost-effective improved wire-shaped spray material, in particular for the arc wire spraying. In determining the wire-shaped spray material, the spray properties of the wire-shaped spray material and the machinability of the spray layer are selectively influenced in addition to the layer properties.

It is a further object of the invention to present a dense, tribologically improved sprayed layer, which can be applied to a substrate in particular by arc wire spraying and can be processed well.

The object is achieved by a method for arc wire spraying with the features of claim 1 and a wire-like spray material with the features of claim 3 and a Lichtbogendrahtspritzitze layer with the features of claim 6.

A coating of such a wire-shaped spray material has comparable properties as a coating of a spray material according to the DE 20 2008 009 964 U1 but the lower carbon content and the increased manganese content have a positive influence on the spray behavior of the spray material. Likewise, the opposite affects DE 20 2008 009 961 U1 decreased silicon content. The copper content improves the corrosion protection of the sprayed layer.

Advantageous developments are the subject of the dependent claims.

An inventive wire-shaped spray material, in particular for arc wire spraying, essentially comprises iron. The sprayed material is formed at least with carbon as a micro-alloy such that at least pearlite, bainite and lower levels of martensite are formed upon solidification of the spray material, micro-alloying elements being additionally provided for forming wear-resistant phases and for improving the tribological properties. Microalloys are those alloys which are predominantly formed from a constituent to which only minor amounts of further constituents are added relative to a total mass. Fine-grained pearlite, consisting of hard Fe ₃ C and ferrite, is a tribologically positive effective phase. Bainite is a conversion phase of medium hardness and wear resistance. Martensite is a hard, wear-resistant structure. The formation of martensite can be selectively influenced by the type of cooling of the spray material and by the choice of alloying components of the microalloy. A layer on a substrate, for example a cylinder surface, produced by means of an arc wire spraying using the spray material according to the invention comprises bainite, wear-resistant islands of martensite and finely striated pearlite.

Tribologically active phases serve to improve the running behavior in critical system states, so that z. B. when tearing off lubricating films excessive wear of the friction partners or their damage can be avoided by adhesive reactions. These states occur in particular in mixed friction areas on z. B. OT and UT areas in the tribosystem cylinder surfaces / piston rings.

In the following an embodiment of the invention will be explained in more detail with reference to a drawing.

Showing:

1 a substrate having a sheet deposited by arc wire spraying.

In 1 is a substrate 1 with a layer deposited by wire arc spraying (LDS) 2 shown. In arc wire spraying, a coating head 3 two wire-shaped spray materials 4 fed. Between the wire-shaped spray materials 4 becomes an arc 5 ignited. This melts the wire-shaped spray material 4 and is targeted by means of a carrier gas to the substrate to be coated 1 Applied where it cools, it solidifies and the layer 2 forms.

The wire-shaped spray material 4 essentially comprises iron. The spray material is formed at least with carbon as a micro-alloy such that predominantly perlite and bainite are formed upon solidification of the spray material.

Furthermore, alloy constituents are provided in the microalloy for the formation of wear-resistant phases (martensite) and for reducing the coefficient of friction.

The following alloy components are provided: Carbon from 0.1% to 0.28% by weight + Silicon from 0.05% to 0.3% by weight + Manganese 1.4% by weight to 2.1% by weight + - Nitrogen 120 ppm. up to 170 ppm. + Copper from 0.05% to 0.25% by weight + Titanium maximum 0.001% by weight + - Phosphorus not more than 0.02% by weight + Sulfur maximum 0.02% by weight + - Vanadium not more than 0,001% by weight - - Aluminum maximum 0.02 wt .-% - Boron maximum 0.0004% by weight -

The quantities are in percent by weight in each case based on a total weight, unless otherwise specified.

• – Kohlenstoff 0,23 Gew.-%
• – Silizium 0,29 Gew.-%
• – Mangan 1,8 Gew.-%
• – Kupfer 0,2 Gew.-%
• – Stickstoff 150 ppm.

It is preferred for the wire-shaped spray material 4 used a microalloy with the following constituents:

• Carbon 0.23% by weight
• Silicon 0.29 wt.%
• Manganese 1.8% by weight
• Copper 0.2% by weight
• - Nitrogen 150 ppm.

The main component of the microalloy is iron.

The arc wire spraying with a wire-shaped spray material formed from this microalloy 4 leads to a particularly homogeneous layer 2 with low porosity and low roughness.

The opposite to the DE 20 2008 00 9964 U1 lower carbon content, the increased manganese content and the silicon content of the microalloy result in an improved spray behavior, which is characterized by the fact that the arc wire spraying produces regular, small, viscous droplets. Due to their viscosity, they decay only slightly in flight and on impact to finer particles and thus tend less to oxidation. A lower surface oxidation promotes the adhesion of the particles to the substrate (layer adhesion) and the adhesion of the particles to one another (layer cohesion).

In addition, the increased manganese content leads to a predominantly pearlitic / bainitic microstructure during the solidification of the sprayed layer 2 ,

The addition of copper improves the corrosion protection of the layer 2 ,

When the layer solidifies 2 produces fine-grained pearlite and bainite. Bainite is a tough intermediate structure of carbonaceous steels. Perlite is a mixed structure of soft ferritic and hard carbide phases. The layer 2 has a soft, ductile matrix of pearlite and bainite with hard, wear-resistant martensite islands.

The addition of nitrogen promotes the formation of wear-resistant nitrides upon solidification of the layer 2 , The nitrides are wear-resistant and tribologically effective in terms of friction coefficient reduction.

The wire-shaped spray material 4 is preferably hot rolled and / or hot drawn and then slowly and controlled cooled in an oven and / or annealed to obtain a ductile structure, so that the wire-shaped spray material 4 remains flexible.

The alloy components of the wire are sized so that the burning of certain elements, eg. B. carbon is taken into account. The alloy composition of the layer 2 is changed according to the burnup. The wire composition is tuned to the target properties of the sprayed layer. Preferably, a surface of the wire-shaped spray material becomes 4 coppered to prevent corrosion of the spray wire.

The wire is low alloy, with the choice being geared specifically to low cost alloying elements.

The resulting sprayed coating shows good workability and excellent tribological properties as well as very good wear resistance.

LIST OF REFERENCE NUMBERS

1

substratum

2

layer

3

coating head

4

wire-shaped spray material

5

Electric arc

Claims (8)

Process for coating a substrate ( 1 ), in which a wire-shaped spray material ( 4 ) in an arc ( 5 ) melted and as a layer ( 2 ) on the substrate ( 1 ) is deposited so that in the layer ( 2 ) after precipitation on solidification, martensite, bainite and perlite are formed using a spray material comprising essentially iron, the spray material ( 4 ) is formed at least with carbon as a microalloy such that martensite, bainite and perlite are formed upon solidification of the spray material, wherein in the microalloy solid lubricant constituents or alloy constituents are provided for the formation of solid lubricant constituents, characterized in that the following alloying constituents are contained in the spraying material used: - Carbon: 0.1 wt .-% to 0.28 wt .-%, - Manganese: 1.4 wt .-% to 2.1 wt .-%, - Silicon: 0.05 wt .-% to 0 , 3 wt .-%., - Copper: 0.05 wt .-% to 0.25 wt .-%, each based on a total weight. Process for coating a substrate ( 1 ) according to claim 1, characterized in that in the spray material used in addition the following alloying constituents are included: - titanium: 0.0001 wt .-% to 0.001 wt .-% and / or - phosphorus: 0.001 wt .-% to 0.02 Wt .-% and / or - sulfur: 0.001 wt .-% to 0.02 wt .-% and / or - vanadium: 0.0001 wt .-% to 0.001 wt .-% and / or - aluminum: 0.001 wt from 0.000 to 0.02 wt% and / or boron: from 0.0001 wt% to 0.0004 wt% and / or nitrogen: 100 to 200 ppm, preferably from 120 to 170 ppm each based on a total weight Wire-shaped spray material ( 4 ) for arc wire spraying, comprising essentially iron, wherein the spray material ( 4 ) is formed at least with carbon as a microalloy such that martensite, bainite and perlite are formed upon solidification of the spray material, wherein in the microalloy solid lubricant constituents or alloy constituents are provided for the formation of solid lubricant constituents, characterized in that the following alloying constituents are present: carbon: 0, 1% by weight to 0.28% by weight, manganese: 1.4% by weight to 2.1% by weight, silicon: 0.05% by weight to 0.3% by weight %., - Copper: 0.05 wt .-% to 0.25 wt .-% in each case based on a total weight. Wire-shaped spray material ( 4 ) according to claim 3, characterized additional additional alloying constituents are contained: titanium: 0.0001% by weight to 0.001% by weight and / or phosphorus: 0.001% by weight to 0.02% by weight and / or sulfur: 0.001% by weight -% to 0.02 wt .-% and / or - vanadium: 0.0001 wt .-% to 0.001 wt .-% and / or - Alminium: 0.001 wt .-% to 0.02 wt .-% and / or - Boron: 0.0001 wt .-% to 0.0004 wt .-% and / or - nitrogen: 100 to 200 ppm, preferably from 120 to 170 ppm, each based on a total weight. Wire-shaped spray material ( 4 ) according to one of the preceding claims 3 or 4, characterized in that a copper plating of a surface of the spray material ( 4 ) is provided. Arc Wire Splashed Layer ( 2 ) based on iron, which has a pearlitic, bainitic, martensitic structure, characterized by its production by means of a process according to claim 1 or 2 and / or by its production with a spray wire ( 4 ) according to claim 3 to 5. Arc Wire Splashed Layer ( 2 ) based on iron according to claim 6, characterized in that its alloy composition compared to that of the spray wire ( 4 ) is changed according to the burnup. Arc Wire Splashed Layer ( 2 ) based on iron according to claim 6 or 7, characterized in that there are also finely divided nitrides in it

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