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Welding wire is a type of metal product; although most solid-wire and seamless cored welding wires have their surfaces coated with copper, some grooved cored welding wires also have their surfaces treated to prevent rust (such as through chemical blackening). On the packaging of welding wire, in addition to plastic bags, some bags also contain a small packet of desiccant; they are further enclosed in paper boxes. Nevertheless, moisture protection remains an issue that must be taken into account when storing welding wire. This is because moisture-absorbed welding wire can increase the content of diffused hydrogen in the deposited metal, leading to defects such as pits and pores; it also deteriorates the weldability and the mechanical properties of the weld metal. In severe cases, this can cause the weld to crack, which is the same as what happens with other welding materials. Of course, since the powder in the flux-cored wire is tightly enclosed within the steel strip, the powder has very little contact with air, and no moisture-absorbing substances such as water glass found in electrodes are used. Therefore, compared to welding rods, welding wires have a very low moisture absorption rate; however, if they are left in a high-temperature and high-humidity environment for an extended period, they will also absorb moisture, leading to rust formation on their surface as well. As the moisture absorption time increases and the amount of moisture absorbed rises, the amount of diffused hydrogen in the deposited metal gradually increases, which is detrimental to the crack resistance of the weld. 1 Storage requirements for welding wire ① Welding wire in its original, unopened packaging must be able to remain in a \"factory-fresh\" state for at least 12 months under the recommended storage conditions. Of course, the maximum storage time depends on the surrounding atmospheric conditions (temperature, humidity, etc.). Recommended storage conditions in the warehouse: room temperature between 10~15°C (up to 40°C), with a maximum relative humidity of 60%. ②Welding wire should be stored in a dry and well-ventilated warehouse; it is not allowed to be stored outdoors or in areas with harmful gases and corrosive substances such as SO2. The interior should be kept clean. When stacking, it should not be placed directly on the ground; it is best to put it on shelves or pallets at a height of at least 300 mm from the ground and walls, to ensure good air circulation and prevent moisture buildup. ③Since welding wires can be used in a variety of welding methods and with many different types of steel, the shape and packaging of these wire coils also come in many different forms. Depending on the wire feeder, the shape of the coil can be divided into disc-shaped, bale-shaped, and cylinder-shaped. Therefore, during handling, avoid leaving things scattered to prevent the packaging from being damaged. Once the packaging is damaged, it may cause the welding wire to absorb moisture and rust. Note: For bundled welding wire, prevent the wire frame from deforming; it should not be fed into the wire feeder. When handling cylindrical welding wire, do not roll it; the container must also not be turned over or tilted, to prevent the wire inside from getting tangled and interfering with its use. 2 Management of welding wire during use ① The welding wire should be used up within 2 days after opening the package. ②After opening the package, the welding wire must be protected from condensation on its surface, as well as from contamination by rust, grease, and other hydrocarbons; its surface should be kept clean and dry. ③When the welding wire is not used up and needs to be left in the wire feeder overnight, it should be covered with canvas, plastic sheeting, or other materials to minimize contact with moisture in the air. ④Wires that will not be used for more than 3 days should be removed from the wire feeder. Place it back in its original packaging, seal it tightly, and then store it in a warehouse with proper storage conditions. 3 Quality management of welding wire ① For the welding wire purchased, each batch shall be accompanied by a quality guarantee certificate from the manufacturer. Each package of products that have passed the inspection must include a product manual and a certificate confirming that the products have passed the inspection. The inner packaging of each wire should be labeled or otherwise marked with the wire model and the corresponding **standard number, batch number, inspection number, specifications, net weight, manufacturer’s name, and address. ②They should be stored separately according to the type and specification of the welding wire to prevent misuse. ③Welding wire should be distributed following the first-in, first-out principle to minimize its storage time. ④If it is found that the wire packaging is damaged, a thorough inspection must be carried out. Wires with obvious mechanical damage or excessive rust cannot be used for welding. It should be returned to the inspector or technical supervisor for inspection and approval for use. 4 Drying of welding wire: Drying is a problem that often arises in the use of electrodes, but for welding wire, it is not explicitly mentioned in existing literature and product instructions. This shows that drying the welding wire before welding is usually unnecessary. In actual construction, some people believe that welded wires that are severely damp can also be dried, but the temperature should not be too high; generally, drying at 120–150°C for 1–2 hours is sufficient. This is beneficial for eliminating pores and reducing the hydrogen diffusion content.