What are the forming processes for steel bends and how can aging be prevented

Steel Bend Processing and Forming Technology
1. Die Forging of Steel Bends. For socket weld and threaded tees, crosses, elbows, and other small pipe fittings with more complex shapes, die forging should be used. The die forging blank should be a rolled profile, such as bar stock, thick-walled steel pipe, or plate. When using steel ingots as raw materials, the ingots should be pre-rolled into strips or used as die forging blanks after forging to eliminate segregation, porosity, and other defects in the ingots. After heating, the blank is placed in the forging die, and pressure forces the metal to flow and fill the die cavity. Flash evaporation will occur after the blank is forged, and the remaining flash evaporation material needs to be washed away to complete all forging work.
2. Free Forging of Steel Bends. Pipe fittings with special shapes or unsuitable for die forging can be manufactured through free forging. The general shape of pipe fittings should be free forged; for example, tee branches should be forged.
3. Machining of Steel Bends. For certain tubular fittings, such as double-socket joints and movable joints, they can be directly processed from bars or thick-walled steel pipes. During processing, the fiber flow direction of the metal material should be approximately parallel to the pipe's axial direction. For tees, crosses, elbows, and fittings, direct cutting from bars is not permitted.

Methods to Prevent Steel Bending Aging: There are many types of steel bending pipes, and they are used in various environments and come into contact with many materials. The lifespan of a pipe depends primarily on its anti-aging ability. Due to material limitations, the anti-aging effect of some pipes may not be significant. The following methods can help prevent pipe aging:
1. During the laying of steel-bending pipes, overcoming axial deformation caused by seasonal temperature differences and controlling thermal expansion are crucial.
2. When connecting hot-melt welded steel pipes to metal pipes and cement pressure pipes, the bend should be firmly bonded. This prevents changes in axial force due to temperature variations in the steel bending pipe material, which could affect sealing performance. The serpentine laying of the hot-melt welded steel pipe should be within the planned allowable range to accommodate temperature changes in the steel bending pipe.
3. Blue or black tubing can be used to squeeze blue ribbons; the latter generally has better UV resistance and anti-aging properties. Protective sleeves are also recommended for public use. Steel bends should be protected from direct sunlight during transportation and storage, and on-site placement time should be very short.

Therefore, users should also try to prevent pipe aging when using steel bends, such as avoiding sunlight exposure and wrapping the pipes with anti-corrosion tape to protect their service life.