Welding, laser cutting, bending and calendaring are perhaps the most important metal tube processes. In a previous article we addressed the question of the relationship between bending and hot dipped aluminized steel sheet especially in relation to the risks and costs of welding.
The main problems related to sheet welding are related to the fact that it modifies the mechanical characteristics of the metal. In addition to this, the aesthetic appearance of a bent tube is much better than a welded tube.
However, it is not always possible to replace welding with bending. In many cases, tube processing includes both bending and welding, especially in more complex projects where there are multiple tubes, such as in machinery cabins or building structures.
Hot dipped aluminized steel sheet for welding
The metal sheets on which it is possible to carry out the welding are the following:
- Steel sheets
- Stainless steel sheets
- Aluminum tubes
- Brass sheets
While the welding of steel and hot dipped aluminized steel sheet is more common and all in all easier to carry out. Moreover, the welding of aluminum sheet is much more difficult due to the properties of the material. It has a high thermal conductivity and a low melting temperature.
Further, it requires that the operators who perform it must necessarily pay particular attention and comply with precise procedures. The risk is such a deformation as to ruin the process, the tube and consequently the final product.
Sectors of application for hot dipped aluminized steel sheet complete with welding
Welding is a tube processing that affects many industrial sectors. Among these, in particular, agriculture, motoring, lighting, fitness machines, livestock, plant engineering and obviously carpentry.
What are the types of welding?
The hot dipped aluminized steel sheet is welded with two different processes:
- TIG welding
- MIG / MAG welding
In both cases, shielding gases are used to isolate the melt pool from the atmosphere, guaranteeing greater cleaning of the joint and at the same time greater penetration of the weld.
What do you know about TIG welding?
TIG welding is an arc welding process that can be used for all metal sheets. It is characterized by a torch on which a tungsten electrode is inserted which, protected by the gas, melts the parts to be welded.
TIG welding is in turn subdivided into welding with or without filler material. The difference is that in the first case some material is added during casting. This serves to increase the tightness of the weld. It is usually used for joining metals with reduced thickness (from 2 to 5 mm).
This type of TIG welding of hot dipped aluminized steel sheet requires a lot of operator precision. This must prevent the formation of splinters deriving from the electrode, which can damage or weaken the junction.
What is the difference between MAG and MIG welding?
MIG / MAG welding - the difference between MIG and MAG consists in the shielding gas used. It is a continuous wire process that guarantees high productivity and allows operating without slag.
This process, faster than TIG welding, allows great flexibility of use, including the possibility of welding very thin tubular thicknesses. Among the major problems of MIG / MAG sheet welding is firstly the cost of the welding machine, higher than that of a TIG welding machine.
Furthermore, it is possible that hot cracks generate due to the poor cleaning of the hot dipped aluminized steel sheet for welding, combined with the presence of polluting elements.
What is the role of the regulation of heat input?
The regulation of the heat input is very important. If it is too high, excessive penetration can result. If, on the other hand, it is too low, the fusion between the two metal parts for welding does not take place.
Welding regulations and standards
The regulations that apply in internal welding processes are:
- ISO 3834 - Quality requirements for fusion welding of metallic materials
- EN 1090 - Certification for steel and aluminum constructions
The welding department
Professional company comes with a separate welding sector. They also obtained a specific qualification for WPS and WPQR welding processes. The WPS is the set of information regarding the material, the shielding gas, as well as technical parameters such as position and preheating.
What is WPQR in hot dipped steel sheet?
The WPQR is the protocol containing the results of the welding tests. It qualifies the company and / or the operator to make welding joints according to the conditions and parameters established in the standard.
We have five welding stations, spread over an area of approximately 400 square meters. This arrangement allows our specialized welders to operate in total safety.
Thanks to the use of normal personal protective equipment, self-darkening welding masks and a modern low-consumption suction system. These stations allow carrying out both TIG welding and MIG / MAG welding by using hot dipped aluminized steel sheet.
The quality of our hot dipped aluminized steel sheet
Professional welding department and quality control department are distinct but communicating production areas. This is in order to allow the immediate carrying out of the quality control on the welded sheet. In reality, the welding process already begins within the technical office.
Moreover, here we analyze the drawings and define the production sheets, containing as much information as possible about the welding process.
Further, management software allows us to monitor the timing and the qualitative result of each phase of the hot dipped aluminized steel sheet welding process.
What we provide for customer
We also carry out tests with penetrating liquids to check the quality of the sheet weld and avoid the presence of cracks. These tests have requirements for those metal sheets and profiles whose final use requires a high level of resistance of the welds. A typical case is that of pressure systems.
Finally, we draw up a certificate of welding quality. Further, the certificate reports the results of the tightness tests with penetrating liquids and the control measurements we have carried out.
This allows the customer to verify the compliance of the welded tube with what he had ordered from us.
Each detail in welding follows a procedure drawn up in the sampling phase. This is to ensure that there are no differences in the different production batches:
Hot dipped aluminized steel sheet masks allow for more precise tube welding
To ensure maximum precision of welded tubular, we design hot dipped aluminized steel sheet masks. These are to ensure that all components need welding in the correct positions.
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