The 304 stainless steel square bar is made with 8 percent nickel and 18 percent chromium. It’s one of the most widely used chromium-nickel alloy because it is highly resistant to heat, corrosion and oxidation. Its oxidation resistance allows it to be continuously serviced in temperatures up to 1650 degrees F without appreciable scaling. Intermittent exposure can be done with temperatures no hotter than 1500 degrees F. Heat treatment can’t be used to harden this alloy. Annealing can be done (recommended right after forging to maintain corrosion resistance) at temperatures between 1900 and 2500 degrees F. It should be cooled rapidly. Thin strips of metal that are thin can be air cooled and thicker sections can be cooled with water to reduce exposure in the region with carbide precipitation.
When cold working this metal, note that slight magnetism can occur. The metal parts that have been cold worked should be stress relieved for a period of 30 minutes to 2 hours at 750 degrees F. Since it has excellent drawability, 304 steel alloys can be used to create kitchen equipment like sinks and saucepans. It has low yield strength and high elongation, which allows it to be used for these applications. It can be formed into other complex shapes as well. When severely forming or spinning this metal, keep in mind that it hardens quickly and that stresses should be relieved afterward.
After welding this metal, annealing is needed to maintain corrosion resistance at adequate levels. Special consideration should be applied when welding this metal so to avoid hot cracking. This is done by ensuring the formation of ferrite inside of the weld deposit.