How to weld cast iron - the features of forming joints
To achieve a quality welding seam on cast iron is problematic enough. This is due to a number of changes in its structure that occur during the heating process. Therefore, it is considered a material that is difficult to weld, especially if welding of cast iron is carried out at home.
Given all the features of this metal, argon welding is considered one of the most reliable methods of obtaining quality welds on cast iron. Application of this technology makes it possible to make a seam, close in its properties with the material to be welded.
Welding of cast iron semi-automatic using argon provides for the gradual heating and cooling of parts. As a result, the formation of graphite occurs in the metal structure, which makes it more ductile. Welding works are carried out using rods and fluxes made of graphite materials.
Cast iron technology - industrial approaches
The modern cast iron welding technology
provides two types of welds: by heating and by cold welding. In modern industry, more than three dozen methods of welding of cast iron without preheating are practiced. The most commonly used are three types:- using steel electrodes.
- with electrodes with non-ferrous metal rods.
- with electrodes of small cross-section with minimum carbon content.
For those who are interested in how to weld cast iron, it will be interesting to know that in industrial conditions for cold welding, the following electrodes are mainly used:
- OZhZ-2 - copper-coated electrodes with special coating;
- MNCH-2 - electrodes with a core, which includes: nickel, copper, iron and manganese.
Suture metal, which is obtained as a result of surfacing with electrodes of the grade OZCH-2, is quite easy to process. The only drawback of such electrodes is their high cost. The cost of MHP-2 electrodes is slightly lower, and besides they can be manufactured at home.
Welding of cast iron with argon is the best option for home use.
In order to obtain the maximum homogeneity of the metal, welding of cast iron by an inverter is widely used. This method is used when working with manual arc welding with connection to a transformer-rectifier.
When working with the inverter, use electrodes made of cast iron rods with a thin layer of coating and a length of up to half a meter. To obtain a weld of a ferritic type, a local heating of the metal to 300 ° C is used.
The most difficult to use, according to experts, are steel electrodes with graphite coating. The seam, which is formed when working with such electrodes, differs in its heterogeneity, which often leads to the formation of cracks. Therefore, they are rarely used in industrial production.
As can be seen from all of the above, only semi-automatic argon welding of cast iron allows obtaining seams of high quality. For the performance of such work, electrodes made in the form of cast-iron plates or flux-cored wire are used.
Also used for welding with argon semiautomatic devices are various fluxes and additives. If you want to learn more about how to weld cast iron with argon, the video on the page of the site will help you familiarize yourself with the entire process in more detail.