Key Points to Consider When Welding Hastelloy Pipes 1. Welding Procedure for Hastelloy Pipes During the welding of Hastelloy pipes, it's important to check the white tape that is placed on the bottom and both sides of the groove. If the tape is not removed before welding, it should be cleaned thoroughly with acetone to avoid contamination and ensure a proper weld. When using the welding wire, it's recommended to use a lower power setting. The heated end of the wire must remain under gas shielding throughout the process. A short arc technique should be used consistently to control the temperature between passes. After the arc is closed, the crater should be filled completely, and the shielding gas should be allowed to flow for at least 30 seconds before stopping. This helps prevent hot cracking in the weld area. It's crucial to avoid any contact between the tungsten electrode and the molten pool or the welding wire. Keep the arc length as short as possible to prevent tungsten inclusion in the weld, which can weaken the joint and lead to defects. The welding speed should be carefully controlled. If the speed is too slow, it can cause excessive heat input, leading to high energy levels that may result in alloy element loss. This can cause overheating in the heat-affected zone, increasing grain size and reducing the mechanical properties of the weld. On the other hand, if the speed is too fast, the molten pool may not be properly protected, resulting in poor metallurgical reactions, incomplete fusion, and potential crater cracks. 2. Safety and Quality Control Measures Welding supervisors and workers should always wear appropriate protective gloves and accessories. When filling the crater, care must be taken to avoid cracks forming in this area. A wind shield should be placed around the welding area to protect the molten pool from external air currents. The gap between the wind shield and the pipe should be maintained at 1 to 2 mm, ideally between 0 and 1.6 mm. The weld surface must be free of cracks, lack of fusion, undercut, porosity, and slag inclusions. It should also pass inspection using X-ray flaw detection to ensure full penetration and proper weld quality. 3. Quality Assurance for Welds All on-site welds must undergo radiographic testing to ensure they meet the required standards. The first-pass welding rate and the surface quality of the weld must be within acceptable limits to guarantee a strong and durable joint. By following these guidelines, welders can ensure that Hastelloy pipes are joined safely and effectively, maintaining the integrity and performance of the material in demanding environments. 13mm Ferro Calcium Cored Wire,30 Ferro Calcium Cored Wire,30 feca cored wire,ferro calcium wire ANYANG TIEFA METALLURGY CO.,LTD , https://www.ferroalloytiefa.com