Flood welding is a process where large amounts of welded metal are placed into a die for the positioning of alloys and metals for strength and to reduce the amount of wear on a cast piece of metal. The process of flood welding large pieces of a product takes quite a long time, with the integral cooling process taking between seven and 14 days depending on the depth of the product.
During flood welding, a large amount of welded material is deposited into the area to be welded; flood welding can deposit around 60 pounds of welded material into a die every hour, according to The Fabricator. Flood welding is commonly used in the production of die-casting products; because of the strength and durability of flood welding parts, the process saves labor and expenses over the service life of the die-cast product.
The process of flood welding is begun by preheating the area to be flood welded. This process takes place in a furnace; the product is heated to a minimum of 800 degrees F. Once the product has been heated to the required temperature, the die remains within the furnace, with the area to be welded exposed for the access of workers. Throughout the welding process, the product is maintained at the preheated temperature and is only cooled when the flood welding is completed. Following the completion of the welding process, the product is again heated to equalize or ensure the entire product is heated to the same temperature. The equalizing process requires the product to be held at the required temperature for a period of one hour per inch of depth of the product. Once equalized, the product remains in a furnace to be cooled slowly to room temperature. This ensures the product remains at full strength and does not crack or become weakened by a rapid temperature drop.
Four types of welding processes can commonly be used during flood welding, according to Forging Magazine. Welding equipment that can be used during flood welding include gas metal arc welding and gas tungsten arc welding. Other techniques include shielded metal arc welding and submerged arc welding. Both flux cored wire and steel electrodes can be used for flood welding.
By using a flood welding process, specific alloys can be produced by heating the metal to a specific temperature and adding welded materials. This process can be used to increase the strength of die cast parts of a product in areas of stress within a product. Die blocks that are imprinted and have become obsolete can be reclaimed for reuse by flood-welding the block, allowing it to be recast for later use.