The 316 stainless steel round tube is an alloy that is mixed with nickel, molybdenum and chromium. This makes this grade of steel tougher and more resistant to corrosion. It has the ability to be used in high heat, warm sea water, chloride environments and oxidizing environments. It has better corrosion resistance and toughness than 304 steel grades, making it a better choice for applications that need these characteristics. However, because it is a tougher steel, it can be harder to machine than 304 metals.
This metal can be welded, machined and formed using hot and cold processes. However, the heat treatment cannot be used to harden the steel. When using forging methods, it is best to use max temperatures up to between 2100 and 2300 degrees F. It’s not recommended to use in temperatures below 1700 degrees F for forging 316 steel alloy. Once forging has been completed, it’s suggested that a final anneal be done to maintain corrosion resistance.
Cold forming also requires annealing afterward, to relieve stresses that may be caused to various parts that have been severely cold formed. Methods that can be used on this product include roll forming, cold heading, bending, deep drawing and swaging. Cold forming is typically easy. Annealing 316 steel should be done at a temperature set between 1900 and 2100 degrees F. Special consideration should be given to avoid warping and distortion.
When welding this metal, special consideration should be given to prevent hot cracking. Proper ferrite formation in the weld deposits can be checked to avoid this. After welding this steel, annealing should be done to maintain max resistance corrosion levels.