Definition of welding vs. soldering
Welding is a process for permanently joining workpieces together. The workpieces fuse together at the joint to form a solid unit, creating a structural connection between the components. In contrast to soldering, where workpieces are only joined at the surface with a solder, welding ensures a deeper connection.
The energy required for welding is supplied from the outside in order to reach the required working temperature. Various additives can be used during welding, such as plastic wires, oxyfuel welding rods and rod and wire electrodes. In addition, additives such as shielding gases, welding flux or special pastes help to support the welding process or make it possible at all. These substances stabilise the melting process and protect the weld seam from external influences.
Welding process
Fire / fusion welding - DEFINITIONThe process used to be called autogenous (out of itself),
because no materials other than the molten metal itself need to be involved. The
gas flame shields the weld pool from the surrounding atmosphere;
When the torch is set to neutral, the area of the flame used for welding is supplied with exactly
When the burner is set to neutral, the exact amount of oxygen required by the acetylene for combustion is supplied to the area of the flame used for welding.
Gas fusion welding - THE PROCESSGas fusion welding, also known as oxyfuel welding, is a welding process in which metal is heated and melted by a hot flame. This flame is created by the combustion of a gas mixture, usually acetylene and oxygen, which reaches temperatures of around 3200°C. A welding wire is often used as a filler material. A welding rod is often used as a filler material to support the joint and improve the strength of the weld.ROTHENBERGER Industrial appliances are: - Roxy Kit Plus (No. 35740) - Roxy Eco (No. 35748) - Roxy 400L (No. 35780)- Roxy Universal (No. 35050)- Roxy Flamm - (France)
Manual arc welding with stick electrodesArc welding uses an electric arc as a heat source. This arc is created by a ‘controlled short circuit’ between a melting electrode, which serves as a filler material, and the workpiece. The high temperature of the arc ensures that the metal melts at the welding point and is combined with the molten flow of the electrode, creating a solid seam.
Welding transformers (e.g. stray field transformers) with or without welding rectifiers, welding converters or welding inverters are used as welding power sources. Depending on the application and the type of electrode, either direct current or alternating current can be used for welding.
Welding electrodes - structure standard designation of stick electrodesStick electrodes consist of a metal core and a coating. The metal core conducts the welding current and melts during welding to form the weld metal. The coating protects the weld seam from oxidation, stabilises the arc and influences the welding properties (e.g. flow behaviour and strength). In Europe, stick electrodes are standardised according to DIN EN ISO 2560. The designation is composed as follows:
E: Symbol for electrodes.
4-digit number: Tensile strength of the weld metal (in MPa), e.g. E 42 for 420 MPa.
Additional letters: Indicate impact energy and coating type,
z. E.G. E 42 4 B 42 H5. Here stands for:
4: Position (all positions except drop weld).
B: Wrapping type (basic).
42: Notched impact energy (42 J at -20°C).
H5: Maximum hydrogen content (5 ml/100 g weld metal).
Welding electrodes - labelling butt welds | fillet weldsButt welds and fillet welds are the most common welded joints. Their labelling indicates which electrodes are suitable for which type of seam. Butt welds join two components at their end faces. Electrodes that offer good penetration and strength are used for these joints. In the labelling according to DIN EN ISO 2560, this is indicated by the position and the type of coating. Example: E 42 2 R - suitable for butt welds in trough position with rutile coating. Fillet welds connect components at an angle to each other, as with T-joints or corner joints. Good flow properties and reliable seam cant are important here. Electrodes for fillet welds are often suitable for all positions. Example: E 42 4 B - universal for fillet welds in all positions with basic coating.
The position specification (e.g. 2 for trough position, 4 for all positions) and the coating type (e.g. R for rutile, B for basic) help to select the right electrode for butt or fillet welds.
Welding electrodes - Labelling direct current | alternating currentDirect current and alternating current welding: a comparison! In welding, a distinction is made between direct current welding and alternating current welding, depending on the type of current supply. In TIG welding in particular, there are specific operating modes that offer different results and areas of application depending on the type of current. By specifically selecting the type of current, welders can significantly improve both the quality of the weld seam and the efficiency of their work.
Rule of thumb for power selection
Direct current welding:
Preferably used for steel and non-ferrous metal alloys.
Alternating current welding:
Ideal for light metals such as aluminium and magnesium.
Arc welding equipment - DIFFERENCES Welding transformers vs. welding invertersWelding transformers are characterised by their simple and robust design and are inexpensive to purchase. However, they also have disadvantages: they require a lot of material, are heavy, only supply alternating current and the polarity cannot be reversed, which limits their possible applications.
Welding inverters, on the other hand, are lightweight and mobile, offer better efficiency and enable precise control of dynamic welding processes. They are versatile as they can supply both direct current and alternating current (AC/DC welding) and can reverse the polarity of the welding current. They also have numerous convenient functions such as high-frequency ignition. One disadvantage, however, is that they are more expensive to purchase and their complex technology can be more susceptible to repairs.Conclusion: Welding inverters are the better choice for many applications due to their mobility, flexibility and higher performance. Welding transformers, on the other hand, are robust and inexpensive, but limited in functionality and range of application.
Arc welders - THE ON TIMEThe switch-on time (ED) of an arc welding device describes the ratio of welding time to cooling time within a ten-minute cycle. As the conversion of the mains voltage into the welding voltage does not take place without losses, a certain cooling phase is necessary to protect the device from overheating. For example, an ED of 40 % means that the device welds for four minutes and cools down in the remaining six minutes. These values serve as standard measurement values that make it possible to compare different devices with each other. Basically, the higher the ED, the fewer forced breaks are required, as the appliance can work for longer before it needs to cool down.The higher the ED (duty cycle), the more valuable (and expensive) a welding machine is. High-quality arc welding units are equipped with a fan for cooling the electrical components and have an automatic thermal control or switch-off function.
Gas-shielded arc welding - WHY GAS SHIELDING?In any welding process, atmospheric oxygen (usually) has a negative effect on the welding result, which is why the introduction of atmospheric oxygen into the weld pool must be prevented. Welding electrodes have a sheathing that is protected during the welding process.
abschmilzt und sich über die Schweißnaht legt – sichtbar als Schlackeauftrag, der mit Schlackehammer, Drahtbürste und / oder Schleifgerät entfernt wird. Beim Schutzgas- Schweißen wird eine endlose Drahtelektrode durch eine Stromdüse geführt und in einem Lichtbogen auf dem Werkstückabgeschmolzen,
gleichzeitig wird über die Gasdüse am Griffstück ein Schutzgas geleitet, das
sich über das Schmelzbad legt und den Luftsauerstoff abschirmt.Protective gases are e.g. argon | carbon dioxide | mixed gases | helium.
MIG | MAG | TIG welding
Welding processes - MIG & MAGMIG and MAG are welding processes in which an endless wire electrode is passed
through a contact tip, where it is electrically charged and melted on the workpiece in the arc with the addition of
and melted on the workpiece in the arc with the addition of shielding gas.
MIG - WeldingMIG = metal inert gas welding process. The shielding gas is NOT ACTIVE in the welding process, an inactive / inert gas is used, e.g. ARGON.
Metal inert gas welding process = MIG - This is used, for example, for welding stainless steel and aluminium.
MAG - WeldingMAG = metal active gas welding process. The shielding gas takes an ACTIVE part in the welding process.
an active gas is used, e.g. CARBON DIOXYD
Metal active gas welding process = MAG - This is used, for example, for welding low-alloy steel.
TIG - WeldingTIG = tungsten inert gas welding process. In TIG welding, a TUNGSTEN ELECTRODE is used to generate the arc on the workpiece. In contrast to wire electrodes in MIG / MAG welding, the tungsten electrode itself does not melt - it only generates the arc by melting a filler rod on the workpiece. An INACTIVE / INERT GAS, e.g. ARGON, is used for the welding process. Suitable welding inverters can be upgraded to a TIG device with an additional package. The prerequisite is an appropriate output - this should not be less than 100 A. Tungsten - InertGas - welding process = TIG - High-quality welding of e.g. stainless steel, aluminium.
TIG - ALUMINIUM WELDINGOnly inverters that allow switching to alternating current, so-called AC / DC INVERTERS, are suitable for welding aluminium. TIG welding of aluminium with a direct current device is not possible! Welding aluminium with a MIG / MAG device using an AL wire electrode and shielding gas works! AC = alternating current - alternating current/ alternating voltage - DC = direct current - direct current/ direct voltage
Plasma welding - What is a plasma cutter?Plasma cutting is a process for the precise separation of electrically conductive materials. The plasma is an ionised gas; depending on the metals to be processed, compressed air, nitrogen, argon, hydrogen, oxygen or mixed gas are used. The plasma cutter generates an arc using an electrode, the plasma gas is passed through a nozzle, it ionises and generates a plasma jet with a temperature of up to 30,000°C. The plasma jet generated in this way hits the workpiece at high pressure, melting the material and blowing it out of the kerf under the pressure of the gas. Depending on the technical equipment of the devices, plasma cutters can be used to cut a wide variety of shapes out of workpieces very precisely and quickly. Plasma cutters with technical equipment in the lower range can precisely cut many metal workpieces from approx. 0.5 to 12 mm thick.