DE102014226411A1 - Influence of weld metallurgy in resistance welding of mixed joints - Google Patents

Abstract

In order to propose a metal composite of a first component and a second component, wherein the two components may consist of chemically different steels and fusion-metallurgically connected by resistance welding, it is proposed to arrange at least partially between the first component and the second component an intermediate layer, wherein the Intermediate layer has a filler material with austenite formers or consists thereof.

Description

The invention relates to a component composite with a first component and a second component connected by resistance welding to the first component, wherein an intermediate layer is arranged at least in regions between the first component and the second component.

Furthermore, the invention relates to a method for producing a composite component of a first component and a second component.

State of the art

For some applications, it is desirable to connect components of different metallic materials together or add. In general, different joining methods for joining metallic components or joining partners are known.

The resistance spot welding of mixed compounds results in the formation of unfavorable phases due to the different chemical composition of the components. Depending on the materials to be welded and depending on the degree of mixing in the different zones of the weld nugget, these are hardness structures, for example martensite or bainite.

In arc welding, this problem can be counteracted by using alloy-adapted filler metals. It is possible to bring the mixed structure in the optimal state for the connection. For example, in laser beam welding and electron beam welding, high-alloy foils are used in order to adjust the microstructure and the associated properties in a targeted manner. Furthermore, it is known to use nitrogen-containing inert gas in the welding of nickel-based alloys for crack prevention. In principle, the resistance welding process could also be used in the manufacture of blended compounds of austenitic high alloy steels of high carbon and manganese content with e.g. ferritic steels are used. However, a martensitic structure is formed in the weld nugget. This hardness peak leads to premature failure of the bond during cyclic loading, so that the properties of the base material can not be exploited. Thus, it is not possible to influence the solidification structure with conventional resistance spot welding.

For this reason, laser beam welding, electron beam welding or gas metal arc welding are currently used to connect austenitic high-alloy steels. To be able to influence the metallurgy via the welding process, a filler material is used. Thereby, the above-described martensite formation can be avoided. Since the molten bath is open and accessible from one side during laser beam welding, electron beam welding and gas metal arc welding, filler materials with austenite formers can be supplied from the outside.

In the DE 10 2004 009 651 B4 For example, a process for welding dissimilar metal joining partners, in particular aluminum-copper joints, is described. It is envisaged that a filler metal is used from a metallic material and the two joining partners with the involvement of the welding filler material by means of an energy beam, preferably laser beam, are interconnected.

The DE 10 2006 059 884 A1 describes an austenitic iron-based filler for welding an austenitic material to another material.

DESCRIPTION OF THE INVENTION: Problem, Solution, Advantages

Object of the present invention is to propose a composite element of a first component and a second component, wherein the two components may consist of different metallic materials and can be connected to each other by means of fusion welding fusion welding.

According to the invention, a component composite comprising a first component and a second component connected to the first component by resistance welding is proposed for this purpose. Between the first component and the second component, an intermediate layer is at least partially disposed. The intermediate layer according to the invention has an additional material with austenite formers or consists of an austenitic filler metal. The austenitic welding filler includes austenite former.

The first and second components comprise a metallic material or consist of a metallic material. In this case, the two components preferably consist of different metallic materials or at least have different metallic materials. Preferably, the two components to be connected are arranged overlapping

By using an intermediate layer between the two components to be joined, wherein the intermediate layer comprises a filler material with austenite formers or consists of an austenitic welding filler, a comparatively simple way is provided to influence the weld metallurgy using a resistance welding process, without changing the actual welding process sequence. It has been found that only minor adjustments to the welding parameters may be necessary and process times otherwise maintained. Furthermore, advantageously no further intervention in the already existing production processes during resistance welding of components is necessary.

According to the invention, a chemically adapted to the two components or joint partner intermediate layer is thus provided, which transferred by melting the structure in the weld nugget in the desired state (avoiding hardness structure). The use of the technological properties of the materials is improved.

By selectively influencing metallurgy, steels which are very suitable and interesting for certain applications can advantageously also be used, but hitherto could not be used because of their low weldability for resistance welding. By inventively proposed influencing the weld metallurgy, the shortcomings can be equalized and develop a further material spectrum.

It is preferably provided that the first component and / or the second component comprises an austenitic material. Particularly preferably, the first component and / or the second component of an alloyed, for example, high-alloy steel, preferably with high carbon and manganese content. In this way, a high strength can be achieved with simultaneous high elongation of the component composite.

Preferably, the intermediate layer between the first component and the second component is formed as an adhesive layer. In this case, the adhesive layer forms the intermediate layer and thus has the filler material with austenite formers or consists of the austenitic filler metal. For this purpose, the adhesive or the adhesive layer has at least one austenite former. For example, as the austenite former, nitrogen may be present in chemically bound form in the adhesive.

Furthermore, it is preferably provided that the intermediate layer is formed as a metal foil. In this case, the metal foil forms the intermediate layer and thus has the filler material with austenite formers or consists of the austenitic welding filler material. For this purpose, the metal foil has at least one austenite former.

It is also preferably provided that the intermediate layer is formed and arranged as a coating on a surface of the first component and / or on a surface of the second component. In this case, the coating forms the intermediate layer and thus has the filler material with Austenitbildnernauf or consists of the austenitic welding filler. For this purpose, the coating has at least one austenite former.

Particularly preferably, the coating can be formed as a zinc layer with at least one austenite former, for example nickel particles. It would also be possible to provide an organic coating with zinc particles for producing the electrical conductivity, in which case nickel particles are added as austenite formers in addition to the zinc particles, or the zinc particles are replaced by nickel particles. Furthermore, an organic coating could be provided, wherein nitrogen is chemically incorporated as Austenitbildner in the coating.

Preferably, the austenitic filler with Austenitbildnern nitrogen, manganese, carbon and / or nickel.

More preferably, the austenitic filler metal has as austenite former based on the total weight of the austenitic filler metal at least between 0.1 and 1.5 weight percent nitrogen and / or at least between 2.0 and 30.0 weight percent manganese and / or at least between 0.02 and 0 , 8 weight percent carbon and / or at least between 8.0 and 30.0 weight percent nickel.

Further, the austenitic filler as the austenite former has from 0.1 to 1.5 weight percent nitrogen and / or from 2.0 to 30.0 weight percent manganese and / or from 0.02 to 0.8 weight percent carbon based on the total weight of the austenitic filler and / or between 8.0 and 30.0 weight percent nickel. Most preferably, between 2.0 and 18.0 weight percent manganese is provided.

Furthermore, cobalt could additionally or alternatively be provided as austenite former.

Using such Austenitbildner the existence range of the gamma single-phase space is stabilized or extended to higher and / or lower temperatures. In particular, when using the aforementioned preferred percentages by weight, the entire steel structure remains metastable at room temperature in Austenitzustand when the martensite start temperature is below room temperature.

• a) Anordnen einer Zwischenschicht auf dem ersten Bauelement und/oder auf dem zweiten Bauelement, wobei die Zwischenschicht einen austenitischen Schweißzusatzwerkstoff aufweist oder daraus besteht;
• b) Zusammenfügen der beiden Bauelemente, derart, dass die Zwischenschicht zumindest bereichsweise zwischen dem ersten Bauelement und dem zweiten Bauelement angeordnet wird; und
• c) Fügen der beiden Bauelemente mittels Widerstandsschweißen, bevorzugterweise mittels Widerstandspunktschweißen.

According to the invention, a method for producing a component composite from at least one first component and a second component is further provided. The method according to the invention has at least the following steps:

• a) arranging an intermediate layer on the first component and / or on the second component, wherein the intermediate layer comprises or consists of an austenitic welding filler material;
• b) joining the two components, such that the intermediate layer is arranged at least partially between the first component and the second component; and
• c) joining the two components by resistance welding, preferably by resistance spot welding.

In contrast to the welding processes such as arc welding or beam welding, the molten bath is not openly accessible to one side during resistance welding, but lies between the components to be connected or joining partners. By means of the method according to the invention, austenite formers can be introduced into the area of the weld nugget via the use of an intermediate layer of a filler material with austenite formers for influencing the weld metallurgy.

Preferably, it is provided in step a) that the intermediate layer is applied as an adhesive layer on a surface of the first component and / or on a surface of the second component. In this case, the adhesive layer can be applied as a liquid adhesive or glued in the form of an adhesive tape. The adhesive layer thus forms the intermediate layer and has the filler material with austenite formers or consists of the austenitic filler metal. At least one austenite former has been introduced in advance in the adhesive or in the adhesive layer for this purpose.

It is also preferably provided in step a) that the intermediate layer in the form of a metal foil is placed on a surface of the first component and / or on a surface of the second component. The metal foil forms the intermediate layer and thus has the filler material with austenite formers or consists of the austenitic welding filler material. In the production of the metal foil, at least one austenite former was introduced into the material for the metal foil in advance for this purpose.

Preferably, it is further provided that the intermediate layer is applied in step a) as a coating on a surface of the first component and / or on a surface of the second component. The coating forms the intermediate layer and thus has the filler material with austenite formers or consists of the austenitic filler metal.

For example, the coating can be applied as a zinc layer on a surface of one of the components, for which purpose at least one austenite former is introduced into the coating.

The coating can advantageously be sprayed on. In this case, the coating is sprayed onto a surface of the first component and / or onto a surface of the second component at least partially in the region of the joints or the regions to be welded.

Brief description of the drawings

They show schematically:

1 : Arranging an Intermediate Layer on a Device

2 : Merging two components, and

3 : Joining of the two components by means of resistance spot welding.

Preferred embodiments of the invention

1 to 3 show individual process steps for a method for producing a component composite 100 from at least one first component 10 and a second component 11 ,

In 1 are two components 10 . 11 a component group 100 shown. In a first step is on the first components 10 an intermediate layer 12 partially sprayed on. Here, the intermediate layer 12 applied at least in the area in which the welded joint is produced by resistance spot welding.

In 2 a next step of the method is shown, wherein the two components 10 . 11 be joined together so that the interlayer 12 at least partially between the first component 10 and the second component 11 is arranged.

After joining the two components 10 . 11 be in a further step, as in 3 shown the two components 10 . 11 using resistance spot welding after applying electrodes to a welding gun 14 joined together. In this case, the two electrodes are each on an outer surface of the first component 10 and the second component 11 put on and initiated the welding process.

LIST OF REFERENCE NUMBERS

100

 components composite

10

 first component

11

 second component

12

 interlayer

13

 Additional material with austenite formers

14

 welding gun

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004009651 B4 [0007]
• DE 102006059884 A1 [0008]

Claims (10)

Component association ( 100 ) comprising a first component ( 10 ) and one by resistance welding with the first component ( 10 ) connected second component ( 11 ), wherein between the first component ( 10 ) and the second component ( 11 ) at least partially an intermediate layer ( 12 ), characterized in that the intermediate layer ( 12 ) a filler material with austenite formers ( 13 ) or consists of an austenitic filler material. Component association ( 100 ) according to claim 1, characterized in that the first component ( 10 ) and / or the second component ( 11 ) has an additional material with Austenitbildnern or consists of an austenitic filler material. Component association ( 100 ) according to claim 1 or 2, characterized in that the intermediate layer ( 12 ) is formed as an adhesive layer. Component association ( 100 ) according to one of the preceding claims, characterized in that the intermediate layer ( 12 ) is formed as a metal foil. Component association ( 100 ) according to one of the preceding claims, characterized in that the intermediate layer ( 12 ) as a coating on a surface of the first component ( 10 ) and / or on a surface of the second component ( 11 ) is trained. Component association ( 100 ) according to one of the preceding claims, characterized in that the filler material with austenite formers ( 13 ) based on the total weight of the filler with austenite formers ( 13 ) as austenite former at least between 0.1 and 1.5 wt .-% nitrogen and / or at least between 2.0 and 30.0 wt .-% manganese and / or at least between 0.02 and 0.8 wt .-% Having carbon and / or at least between 8.0 and 30.0 wt .-% nickel. Method for producing a component assembly ( 100 ) of at least one first component ( 10 ) and a second component ( 11 ), characterized by at least the following steps: a) arranging an intermediate layer ( 12 ) comprising or consisting of a filler material with austenite formers on the first component ( 10 ) and / or on the second component ( 11 ); b) assembling the two components ( 10 . 11 ), such that the intermediate layer ( 12 ) at least in regions between the first component ( 10 ) and the second component ( 11 ) is arranged; c) Joining the two components ( 10 . 11 ) by resistance welding. Method according to claim 7, characterized in that the intermediate layer ( 12 ) in step a) as an adhesive layer on a surface of the first component ( 10 ) and / or on a surface of the second component ( 11 ) is applied. Method according to claim 7 or 8, characterized in that the intermediate layer ( 12 ) in step a) as a metal foil on a surface of the first component ( 10 ) and / or on a surface of the second component ( 11 ) is launched. Method according to one of claims 7 to 9, characterized in that the intermediate layer ( 12 ) in step a) as a coating on a surface of the first component ( 10 ) and / or on a surface of the second component ( 11 ) is applied.

Images