Monthly Archives: February 2019
Often the multiprocess welders have to weld ad work on stainless steels. The stainless steels, also known as steels that resist on corrosion are part of the iron-base alloys. As commercial welders know, these steels do not rust and have high resistance on the attacks of chemicals, gases and liquids. Most of the stainless steels come with good ductility and low-temperature toughness. MIG welders, Arc welders, TIG welders, and Stick welders, further say that these steels are resistant to high temperatures and show good strength properties. As a rule, the stainless steels contain iron and chromium, which could be varying from 11 to 30 %. It is the chromium that secures the basic corrosion resistance of the stainless steels. In general, there are almost 15 different types of chromium stainless steels.
The commercial welders know that to certain stainless steels is added nickel. These steels are known as chromium-nickel stainless steel. Due to the nickel, the thermal conductivity
In order for the MIG welders, Arc welders, Stick welders and TIG welders to perform a good hard surfacing or to do an overlaying operation, then a welding procedure has to be done. The welding process must be related to a certain part that is surfaced, as well as to the composition of that part.
The multiprocess welders should know which welding process needs to be used and which method to be applied. There are also several operations that need to be done before the welding such as cleaning, undercutting, etc.
Stick welders, TIG welders, Arc welders, and MIG welders should also be aware of the preheat temperature, as well as about the necessary techniques that need to be done. For example, they have to be aware of the hardsurfacing pattern, the welding wire method – waving or beading, as well as the adjacent beads interface and the post-welding operations – peening and cooling.
The Arc welders,
The TIG welders, MIG welders, Arc welders and Stick welders are pleased that the American Society for Metals Committee on Hardfacing has organized a hardfacing alloys classification. Thanks to that, the multiprocess welders can recognize five main groups of these alloys, where the division is based on their alloy content. We already presented group 1 – the low-alloy steels with the main alloying element in being chromium and their two subgroups. The multiprocess welders should also recognize the other four groups, namely:
Group 2 – these are the alloyed steels with higher content. The group also has two subgroups. The first one has chromium being the chief alloying element that has total alloy content of 12-25 %. Some of these alloys also contain molybdenum. The second subgroup has molybdenum as the principal alloying element, yet some of them also contain chromium. MIG welders, TIG welders, Stick welders and Arc welders know that the alloyed steels from thi
All multiprocess welders know well that there is no one standard method for the classification of the hardfacing alloy and for the specification of the different weld rods, welding wire and electrodes. In fact, as TIG welders, Stick welders, MIG welders and Arc welders know well, most of the hard facing electrodes which are available cannot be set under the most used specifications.
Most of the suppliers of filler metal are offering data setting classes and categorize their products into these classes. Some of the suppliers also offer information on how specific products can be applied and used in the different industries. In this way the multiprocess welders will know when and how to use them.
Like many of the Stick welders, TIG welders, Arc welders and MIG welders know, the American Society for Metals Committee on Hardfacing has established the best possible classification of the hardfacing alloys. According to that classification, the multiprocess welders can spot
TIG welders, Stick welders, Arc welders, and MIG welders use a special classification system in order to organize the different types of wear and to name the metal deterioration processes that change the welding wires and metal surfaces.
We have already discussed the processes of abrasion, thermal shock and impact wear. Now will be presented the rest of the surface wear types that are easily recognized by the multiprocess welders:
Erosion – this process of wearing away is known to the Stick welders, TIG welders, MIG welders and Arc welders as destruction of metals and of other materials, caused by the abrasive action of water that carries abrasive materials. Very often, this type of wearing hits the pump parts.
Stick welders, MIG welders, TIG welders, and Arc welders are well aware that the wear or the so called deterioration of the surfaces is problem in many industries, including the welding industry. The wear of the welding wire and the filler rods, as well as all other materials used in the processes that multiprocess welders apply is the result of erosion, impact, abrasion, oxidation and corrosion.
Sometimes the wear is due to a combination of all those processes. The effects left from the wear can be repaired by the TIG welders, Stick welders, Arc welders, and MIG welders when they apply welding. When the multiprocess welders use special welding filler metals,
Every commercial welder will tell you that the arc length, also called arc gap, is the distance between the part that has to be welded and the electrode tip. The arc length depends on the arc stability, the weld current and the concentricity of the part. The task of the commercial welder here is to keep the electrode at a certain distance from the surface so that there is enough place to avoid stubbing out. In general, the arc length is 0.10 inch and this measurement is taken as a base. One half of the weld penetration is combined with the base measurement and this results in the arc length for a certain amperage.
The weld speed that the commercial welder has to choose is the speed of travel of the torch ad it is dependent on the flow rate of the material that has to be welded and also on the thickness of the material that needs to be welded. In general the commercial welders should weld as quickly
Every commercial welder will tell you that the typical welding system comprises of several elements which include supply of welding power, weld controller, welding torch, as well as tungsten electrode. Commercial welders know that during the gas tungsten arc welding process besides the welding equipment they should also use certain welding parameters. The weld program has specific welding parameters that are developed so that a certain weld quality can be reached.
When a certain parameter in that weld is changed, this leads to a change in the final quality of the weld. In general, the commercial welders write down the welding variables and store them in the memory of the welding equipment.
Sometimes in certain welding applications of great precision and purity, the welders are using specifications with recommended welding parameters that include diameter, base material, weld joint, and also type and purity of the shield gas, as well as arc length, surface condition, tungsten
Known as GTAW process, as the commercial welders call it, the gas tungsten arc welding process was created back in the 1940s when it was necessary for aluminum and magnesium alloys to be welded for the use of the aircraft industry and applications.
The gas tungsten arc welding process was developed as a new method of welding as it was necessary for welding to be done on these materials in a better way than the SMAW or the shielded metal arc welding process. Nowadays, the commercial welders are using the GTAW welding process when they have to weld precision parts such as metal bellows, batteries, various medical components, pacemakers, different surgical tools, etc.
In the beginning, the commercial welders were using the helium as the shielding gas and thus they named the welding process ‘heliarc welding’. Then the helium was replaced by the argon, which became the
The process of plasma arc welding is quite popular with the commercial welders. In fact, as every good commercial welder knows, the plasma arc welding has a wide range of applications. The process of plasma arc welding can slowly start an arc to some small components and to the tip of wires and proceed with making welds that are repeatable and come with short periods of welding. Commercial welders confirm that this is quite to the advantage when the welding components are wires, needles, probes, thermocouples, light bulb filaments, as well as surgical instruments.
When the commercial welder has to work with electronic components or with various medical instruments that are hermetically sealed or are sealed through welding, then the plasma process gives them the chance to weld close to the delicate seals, to reduce the heat input and to start the arc without the high frequency electrical noise as it could damage the internal parts of the electrical device.