Industry Knowledge
What should be paid attention to when storing tungsten electrode
Environmental control
Temperature and humidity management
The storage environment of tungsten electrode has strict requirements and needs to be kept under constant temperature and humidity conditions with a temperature not exceeding 25°C and a humidity not exceeding 40%RH. High temperature environment will accelerate the oxidation process of tungsten electrode, which will lead to the increase of grains and the decline of its performance; while high humidity may cause surface corrosion, especially for electrodes containing rare earth oxides (such as thorium and cerium). Nantong Rongxin recommends that customers deploy industrial-grade temperature and humidity monitoring systems to ensure that environmental parameters can be monitored and controlled in real time.
Dust prevention and purification
The storage area must meet the Class 8 cleanliness level of ISO 14644-1 standard, and the diameter of particles in the air should be controlled below 5μm. The adhesion of dust may form a micro-current path, thereby accelerating the electrocorrosion of the electrode surface. To this end, the company can provide customized storage cabinets equipped with HEPA filtration systems and positive pressure ventilation devices to effectively isolate the intrusion of external pollutants.
Light and radiation protection
Avoid direct sunlight and ultraviolet radiation to prevent photodegradation of the surface coating of the tungsten electrode (such as red thorium oxide coating). Electrodes containing radioactive elements (such as ThO₂) need to be stored in lead shielded containers.
Packaging protection
Inner layer protection
Tungsten electrodes need to be sealed in vacuum aluminum foil bags, filled with 99.999% high-purity nitrogen to prevent oxidation. The "three-proof" packaging technology developed by Nantong Rongxin extends the shelf life of the electrode to five years in a sealed state by adding antioxidants and antistatic agents.
Middle layer buffering
The use of EPE pearl cotton and air column bags in the packaging for secondary protection can effectively absorb mechanical shock during transportation and storage. The company provides customized foam molds to ensure that the fixed position error of the electrode in the tray is controlled within ±1mm.
Outer layer labeling
The model, batch number, production date and radiation warning label (if applicable) of the electrode must be clearly marked on the packaging box. Nantong Rongxin uses blockchain traceability technology. Users can obtain the full life cycle information of the electrode, including the source of raw materials, processing parameters and quality inspection reports by scanning the QR code.
Regular inspection
Appearance inspection
A visual inspection should be carried out once a month, focusing on whether there are cracks, oxidation spots or coating shedding on the electrode surface. For thin electrodes with a diameter of less than or equal to 1.6mm, a microscope magnified to 50 times is required for detailed inspection.
Performance test
5% of the electrodes need to be extracted every quarter for conductivity and work function testing. Nantong Rongxin's intelligent detection system can automatically record test data and generate performance decay curves to predict the remaining service life of the electrode.
Inventory rotation
Follow the "first in, first out" principle to ensure that the storage time of the electrode does not exceed two years. For electrodes stored for a long time, it is recommended to replace the nitrogen every six months to prevent the oxygen concentration in the packaging bag from exceeding the standard, thereby ensuring the stable performance of the electrode.
DCEN mode
In the welding industry, DCEN mode is widely regarded as an ideal choice for welding carbon steel and stainless steel. The working principle of this mode is to connect the tungsten electrode to the negative electrode and the workpiece to the positive electrode, and electrons flow from the tungsten electrode to the workpiece, forming a "cathode atomization" effect. This process effectively removes the oxide film on the surface of the workpiece, thus providing a good foundation for welding.
The advantages of this mode are obvious. First, the DCEN mode can achieve the characteristics of high penetration and narrow welds. Since the electrons hit the surface of the workpiece at high speed, the heat is concentrated, and the penetration can reach 60%-70% of the thickness of the parent material, which is particularly suitable for thick plate welding. Secondly, low oxidation risk is another significant advantage. Inert gases (such as argon) can completely isolate the air, avoid oxidation and nitridation of the weld, and thus ensure the mechanical properties of the joint. In addition, the service life of the tungsten electrode has been significantly extended. Due to the relatively low temperature of the tungsten electrode (about 2000℃) and reduced evaporation loss, Nantong Rongxin's thoriated tungsten electrode (EWTh-2) has a 40% longer life in the DC positive connection mode than pure tungsten electrodes.
The application scenarios of the DCEN mode include high-strength steel welding in shipbuilding, pressure vessel head splicing, and repair of heavy machinery shaft parts, fully demonstrating its wide applicability in industrial applications.
DCEP mode
The DCEP mode shows excellent performance in aluminum-magnesium alloy welding. Its working principle is that the tungsten electrode is connected to the positive electrode, the workpiece is connected to the negative electrode, and the positive ions bombard the surface of the tungsten electrode to form an "anode cleaning" effect, which effectively removes the oxide layer on the surface of the tungsten electrode.
The advantages of this mode are mainly reflected in high arc starting stability and low electrode burnout. The bombardment of positive ions keeps the tip of the tungsten electrode clean and reduces the arc starting voltage by 15%-20%, which is very suitable for automated welding. In addition, the current density is 30% lower than that of the DC positive connection mode, and the temperature of the tungsten electrode tip is controlled within 1800℃. The burnout rate of Nantong Rongxin's cerium tungsten electrode (EWCe-2) in the reverse connection mode is only 0.05mm/h, which significantly extends the service life of the electrode. The improvement of welding speed is also a highlight of the DCEP mode. The arc stiffness is enhanced, the fluidity of the molten pool is improved, and the welding speed is 2-3 times higher than that of the traditional method.
The application scenarios of the DCEP mode cover the welding of battery trays for new energy vehicles, the manufacturing of aluminum-lithium alloy structural parts for aerospace, and the production of lightweight rail transit bodies, demonstrating its strong adaptability in the field of high-tech.
Alternating current (AC) mode
The alternating current (AC) mode provides the ultimate solution in aluminum-magnesium alloy welding. Its working principle is that the current direction is periodically switched (60Hz), the positive half cycle realizes "anode cleaning", and the negative half cycle maintains arc stability, thereby achieving a balance between cleaning effect and welding efficiency.
The self-cleaning ability of the AC mode is one of its major advantages. The positive half cycle effectively removes the oxide film, and the negative half cycle stabilizes the arc. No additional flux is required, and the surface finish of the weld can reach Ra1.6μm. Precise control of heat input is another important feature of the AC mode. By adjusting the positive and negative half-cycle time ratio (EN/EP ratio), 10%-100% energy distribution can be achieved to adapt to the welding of aluminum plates of different thicknesses (0.5mm to 10mm). In addition, the AC arc has a very strong anti-interference ability to the magnetic field. Nantong Rongxin's lanthanum tungsten electrode (EWLa-1.5) can still maintain an arc offset of ≤0.5mm in a strong magnetic field environment.
The application scenarios of this mode include aluminum-magnesium alloy welding of ship decks, welding of automobile body panels, and the manufacture of heat sinks for electronic products, which fully reflects its important position in modern manufacturing.
Pulse TIG mode
The pulse TIG mode forms a "melt droplet transition-cooling and solidification" cycle by superimposing a pulse current (peak current can reach 3-5 times the basic current) on the basic current (10-50A), thereby achieving a perfect combination of precision welding and efficient production.
The significant advantage of this mode is the reduction of the heat affected zone (HAZ), which has been reduced by 50%. The pulse current causes the molten pool to solidify quickly, reducing the tendency of grain growth and increasing the hardness of the weld by 20%-30%. In addition, the pulse TIG mode can also improve the aesthetics of the weld and ensure that the welding quality reaches a higher standard.
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