FR2571286A1 - Perforated weld joining using arc submerged in weld powder - Google Patents

Abstract

Method welding using unalloyed, low, average and high alloy steels as well as non-ferrous materials as the joint material using the perforated weld joint method under basic weld powder consists of using a weld time per hole of 0.2-60 sec. with a hole dia. of 2-30 mm. The joint material is in wire form and the ratio of wire dia. to hole dia. is 0.6-15.

Description

"Welding process for the production of junctions by
hole welds and / or plug welding
The invention relates to a method for manufacturing junctions by welding in holes of unalloyed, weakly alloyed, moderately or strongly alloyed steel, as well as non-ferrous materials.

 It is known that junctions by hole welding can be established according to the methods EH (Electric hand welding), WIG (Arc welding in inert atmosphere with tungsten electrode), MIG / MAC (arc welding with wire electrode in inert atmosphere, arc welding with electrode wire in active atmosphere) and under slag.

 When they are used to make junctions by welding in holes of materials and combinations of materials difficult to weld, these methods have drawbacks, from the point of view, among others, of the possibility of mechanization, of the requirements imposed on the personnel who must welds, and determined quality criteria for welds.

 The object of the invention is to propose a welding method for the production of junctions by hole welds, in which the disadvantages of the known methods are only eliminated, but which also offers, as will be demonstrated below, special advantages.

 The invention proposes for this purpose that, as a welding process, use is made of the welding process under flux, with a basic flux to be welded, while the thermal action on the part is kept low, the duration of welding by holes is between 0.2 and 60 seconds with a diameter of the holes between 2 and 30 mm, in that, as a welding rod, non-alloyed steels, low, medium and high alloy are used as well as materials non-ferrous, the ratio between the diameters of the welding rod and the holes being between 1.5 to 8 and 0.6 to 15.

 When the process according to the invention is used, it may be advantageous to use a regulation of the distance to keep the length of the free welding rod approximately constant, and as an ignition aid, to a current source. at high frequency, to obtain contactless ignition.

The process according to the invention has the following advantages over the processes of the prior art
Compared to the EH process (electric hand welding)
- possibility of mechanization,
- reproducible results,
- independence of the quality of service personnel,
- weak effect of heat possible.

Compared to the WIG process (arc welding in an inert atmosphere with tungsten electrode)
- shorter welding times,
- weak effect of heat possible,
- greater ease of use,
- no link fault,
- low tendency to form cracks
- slowly flowing alloys ensuring seamless welding.

Compared to the MIG-MAG process (arc welding with wire electrode in an inert atmosphere, arc welding with wire electrode in active atmosphere)
- easier to use,
- no link fault,
- slowly flowing alloys ensuring seamless welding,
Compared to the slag welding process
- shorter welding times,
- lower heat input,
- small dimensions of the possible holes,
- most metallic materials are weldable.

 - Careful tests and uses in practice have shown that by using the process according to the invention, it is possible to obtain significantly better and more regular results, precisely on materials which are difficult to weld, than with the processes. according to the prior art.

 The method of the invention has been used, for example, for the manufacture of guide grids of turbochargers. The materials used for this purpose tend to soak. Thanks to the shorter duration of the welding times and the lower heat input, it was possible here to eliminate the thermal post-treatment. This made it possible to avoid significant costs and risks.

 With materials susceptible to hot cracking, based on iron, nickel or cobalt, it is possible, thanks to the shorter welding time, to keep the area where there is a risk of crack formation small, allowing to this extent, avoid heat cracks or keep them below a critical length.

Claims (3)

 10) Welding process for production. of junctions by welding in holes of unalloyed, weakly, moderately or strongly alloyed steels as well as of non-ferrous materials, characterized in that, as a welding process, the welding process under flux is used, with a flux to be welded basic, while the thermal action on the part is kept low, the duration of welding by holes is between 0.2 and 60 seconds with a diameter of the holes being between 2 and 30 mm, in that, as welding rod, unalloyed, low, medium and high alloy steels as well as non-ferrous materials are used, the ratio between the diameters of the welding rod and the holes being between 1.5 to 8 and 0, 6 to 15.  20) Process for the production of junctions by welding in holes according to claim 1, characterized in that a distance regulation is used to keep the free length of the welding rod approximately constant.  30) Method for producing junctions by welding in holes according to claims 1 and 2, characterized in that, as an ignition accessory, a high-voltage voltage current source is used, for contactless ignition.