DE3203789A1 - Method of manufacturing high-temperature, long-time contact and gas nozzles for welding units - Google Patents

Abstract

The method describes the manufacture of contact and gas nozzles which prevents alloying of the melting-back welding wire or of welding spatter with the nozzle by coating with ceramic powders or by lining with a ceramic bush or by the use of a ceramic nozzle with correspondingly effective thermal conductivity and anti-wetting feature.

Description

Dear Sir or Madam,

we bring the following patent for the production of high-temperature long-term current and gas nozzles for welding systems for registration: Designation: Process for production High-temperature long-term current and gas nozzles for welding systems, called HLS or HLG nozzles.

Process description: Today metallic contact nozzles are made of copper or refined steel is used. About alloying melt-back welding wire or to avoid welding spatters with the nozzle, these nozzles are mostly used sprayed organic release agents, the effect of which is short-lived, and only at low temperatures.

It is also known that these release agents outgas and thus during welding can lead to the formation of cavities, especially at the start of welding.

According to this invention, the nozzles are made with a ceramic powder coated, or lined with a ceramic socket, or by ceramic replaced. It is essential that this ceramic is also used at high temperatures not wetted with metals, not embrittled, no outgassing shows even at high levels Temperatures has a high electrical insulation value and good thermal conductivity owns.

This can be achieved for the contact tip by the following measures: a) The contact tip is made by dipping, spraying or another type of coating with ceramic powders, primarily boron nitride, against weld spatter or melting back Welding wire protected.

b) The contact tip is against weld spatter and melt back Welding wire protected in such a way that the front part of the nozzle with ceramic molded body is booked out. fSketch 1) When choosing ceramics, it is essential that this no reaction even at high temperatures 1 wetting with metals at one time shows good thermal conductivity.

Problems similar to those with the contact tip occur with the currently im Commercially available gas nozzle. The conventional gas nozzles have to be specially designed for MIC-MAG welding is also protected against spatter by an organic release agent be, resp.

show a relatively strong in TIG and electron beam welding Embrittlement at high temperature and energy density.

In addition, the conventional nozzles partially fuse and outgassing, which can lead to the aforementioned voids in the weld seam.

These deficiencies can be remedied by the following measures or

a) The nozzle is either dipped or sprayed or another type of coating with ceramic powders, primarily boron nitride, protected against weld spatter.

b) Part or all of the nozzle is made of a highly thermally conductive one Ceramic, mainly boron nitride, manufactured (sketch 2), so that no reaction / wetting with metal splashes can occur even at high temperatures. At the same time is a good thermal conductivity and a good heat transfer ensured, since no additional Isolation is necessary.

When using boron nitride there is also outgassing, embrittlement or Melting can also be excluded at temperatures above 12000C, which leads to a significant Improvement of the weld seam quality can lead.

This ceramic nozzle can also be made of other ceramic materials or can be produced as a composite material with I without boron nitride, if there is no Disadvantage in terms of thermal resistance and wettability, as well as electrical Conductivity arises.

Product advantage: Because there is wetting between boron nitride and practically all metallic compounds and pure metals. to temperatures far above 1200 0C can be ruled out, * wear of the HLS contact tip or the HLG gas nozzle in the conventional sense largely excluded.

If a gas nozzle made of pure boron nitride is used, is no additional insulation, which would have a negative effect on heat dissipation necessary. Also there is neither embrittlement, nor melting, nor outgassing expected even at high temperatures, which means that even when welding High-temperature steels worked without interruptions and with high energy density can be.

Blank page

Claims (12)

Claims: 1,) Process for the production of coated contact nozzles, d a d u r c h e k e n n n z e i d h n e t that by coating a conventional Contact tip with ceramic powders or ceramic powder mixtures no wetting between Weld spatter or melting back welding wire and the contact tip occur can. 2.] Claim like method 1), but d a d u r c h g ek e n n notices that boron nitride powder is used. 3.) Claim like method 1 J and 2), but d a d u r c h g e k e Note that the powder is applied without a binder, so that too no outgassing takes place at high temperatures. 4.) Process for the production of high-temperature long-term contact nozzles (HLS nozzles), denoting that the front part of the flow Contact nozzle with a hot-pressed, pressureless sintered or cold-pressed, binder-free boron nitride bushing. 5.) Claim like method 4), but d a d u r c h g e k e n nz e i c h n e t that another high temperature resistant ceramic with good thermal conductivity and resistance to molten metals is used. 6.) Claim like method 4) and 5), but d a d u r c h g e k e It is not stated that the ceramic is processed with bonding agents and pressed in will. 7.) Process for the production of coated gas nozzles, d a d u r c h notices that by coating a conventional metallic Gas nozzle with ceramic powders or ceramic powder mixtures no wetting between Weld spatter and gas nozzle can occur. 8.) Claim like method 7), but d a d u r c h g e -k e n n z Note that boron nitride powder is used. 9.) Claim like method 7) and 8), but d a d u r c h g e k e Note that the powder is applied without a binder, so that too no outgassing takes place at high temperatures. 10.) Process for the production of high-temperature long-term gas nozzles (HLG nozzles), d u r c h e k e n n n z e i c h n e t that the nozzle is partially or completely off a hot-pressed, pressureless sintered, or cold-pressed, am the free boron nitride nozzle is manufactured. 11.) Claim like method 10), but d a d u r c h g ek e n n z e i c h n e t that another high temperature resistant ceramic with good thermal conductivity and resistance to molten metals is used. 12.) Claim like method 11) and 12), but d a d u r c h g e it is not indicated that the requirement for freedom from binders does not apply.