[China Aluminum Network] Base Material Preparation: To weld aluminum, the welder must be careful to clean the parent material. Use oil or solvent to remove any oxide and hydrocarbon contamination on the exterior of the aluminum. The surface of the aluminum exhibits an oxide ablation temperature of 3700 degrees Fahrenheit, while the underlying aluminum parent alloy ablates at 1200 degrees Fahrenheit. Thus, the appearance of any oxides remaining on the aluminum parent material will restrict the penetration of the filler metal into the workpiece.
To eradicate the oxides on the outside of the aluminum, stainless steel wire brushes may be used or the solvent may be used for corrosion. When using a stainless steel brush, it can only be removed in a fixed direction. Be careful not to be too hard or careful: rough movements will form oxide-embedded aluminum parent materials. Together, use stainless steel brushes only on the exterior of the aluminum. Do not use brushes that have been used on stainless steel or carbon steel. In the course of using chemical solvents, it is necessary to ensure that the solvents are cleansed before welding.
To reduce the adverse effects of hydrocarbons with a greater degree of oil or solvent, we must also use oil removal agents. Together make sure that the degreaser does not contain any hydrocarbons.
Preheating: Preheating aluminum workpieces can help prevent weld cracks from occurring. The preheat temperature should not exceed 230 degrees Fahrenheit. Use a thermometer to monitor the temperature to avoid overheating. In addition, continuous welding at the beginning and end of the weld zone can assist in enhancing preheating. Welders should also preheat a thick layer of aluminum while welding the thin material.
Disposal speed: The process of aluminum welding requires high temperature and high speed disposal. Unlike steel, the higher thermal conductivity of aluminum requires the use of higher current voltage settings and higher welding speeds. If the welding speed is too slow, there will be too much penetration of the weld, especially when welding thin materials.
Maintenance gas: Argon is used as the more commonly used aluminum welding maintenance gas because of its excellent cleaning function. At the time of welding the 5XXX-series aluminum alloy, the maintenance gas used is a mixture of argon and helium. The share of more 75% helium can reach a better effect of reducing the effect of magnesium oxide.
Welding wire: Select and fill aluminum wire near the melting point of the base metal. The more the welder can constrain the scale of metal ablation, the simpler it is to weld the alloy. Use a diameter of 3/64 - perhaps 1/16 inch. The larger the diameter of the filler wire, the easier it is to feed the wire. To weld thin data, using a 0.035-inch-diameter wire plus a pulse-welding process, a low-speed wire feed (approximately 100 to 300 inches per minute) works well.
Concave data welding: In aluminum welding, spark splashes can cause welding failure. Cracks are a result of the shortening from the high-speed thermal expansion of aluminum to the formation of many cooling. The danger of welding cracks is greater at the time of the welding concave data, because the data surface pits will be shortened, and the data will tear when cooled. Therefore, the welder should make a convex-shaped pit, and the convexity will compensate for the shortening formed during welding.
Power supply selection: When selecting the voltage of the gas metal arc welding machine for welding aluminum materials, it is question that the chief demand thinks about the droplet transfer splash or impulse.
Stable current and stable voltage welding machine can be used to erupt arc welding. The eruption arc is to spray a small droplet of molten metal on the electrode through the welding arc to the base material. In the application of welding thick aluminum, it is required that the welding current exceeds a stable current of 350 amps, which can achieve a better effect.
The pulse transition is usually performed with the support of an inverter power supply. The new power supply includes a built-in pulse program. At the time of the gas metal arc welding pulse, there is a drop of filler metal transition from the welding electrode to the workpiece in each current pulse. During this process, the positive electrode droplet transfer will occur, resulting in less spatter and higher welding speed. . The use of pulsed gas metal arc welding technology to weld aluminum material, heat input control is also very good, but also can easily perform dislocation welding, so that the welder with a lower wire speed and low current for thin steel welding .
Wire feeder: The preferred method for sending soft aluminum wire over long distances is push-pull wire feeding. This approach uses closed wire feed to maintain the wire from the environment. The stable torque in the wire feeding structure and the variable speed motor act as wire feed power, guiding the wire through the welding torch to achieve stable output and speed. The torch's high-torque motor pulls the welding wire, ensuring that the wire feed speed and welding arc are coordinated.
Some welders use the same wire feeder to transport steel wire and aluminum wire. Under such conditions, the use of plastic or nylon liners can help achieve smooth and coordinated common wire (aluminum) action. At the time of detailed welding, try to keep the vertical of the welding torch cable to reduce the wire feeding resistance. Carefully check the concentricity between the automatic roller and the guide tube to avoid scratching of the aluminum material.
Use an automatic roller designed for aluminum. Set the automatic roller tightly to reach a constant wire feed speed. Too tight settings can cause deformation of the welding wire and unstable feeding of the wire: if it is too loose, unstable wire feeding can result. Both conditions will directly lead to instability of arc welding and welding porosity.
Welding torch: Use different welding torch pads to weld aluminum. To prevent the wire from being disturbed, try to tighten the ends of the pad together to eliminate the gap between the pad and the gas diffuser.
Frequent replacement of the liner can reduce the adverse effects of potential oxides on the rough appearance of the aluminum wire on the formation of the wire. When the welding current exceeds 200 amps, it is necessary to use a water-cooled welding torch to cool and reduce the difficulty of wire feeding.
Butterfly Valve is either can be a shut-off valve or a Control Valve , the open and close action is controlled by rotarying the round disc, it is mainly for cutting off the pipeline. Butterfly valve has the characteristics of simple structure, small size, light weight, quick switch and small torque. Plastic butterfly valve is mainly used for corrosive liquid, body and disc material is made by PVC, CPVC, PVDF, PP. seat material is usually made by EPDM, NR, NBR, VITON and PTFE.
Butterfly valve is mainly used in industrial water treatment, fish farm, mining, steel, chemical and other industries. Ningbo RMI Plastic Co.,Ltd offer different kind plastic valves include PVC Butterfly Valve, CPVC Butterfly Valve, PVDF Butterfly Valve, PP Butterfly Valve , PPH Butterfly Valve, PTFE lined butterfly valve.
Butterfly Valve
PVC Butterfly Valve,PP Butterfly Valve,CPVC Butterfly Valve,PVDF Butterfly Valve
Ningbo RMI Plastic Co., Ltd. , https://www.rmiplast.com