Stainless steel Stainless steel In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable" (inoxidizable), is a steel alloy with a minimum of 10.5% chromium content by mass and a maximum of 1.2% carbon by mass. Stainless steels are most notable for their corrosion resistance, which increases with increasing chromium content. Additions of molybdenum increase corrosion resistance in reducing acids and against pitting attack in chloride solutions. Thus, there are numerous grades of stainless steel with varying chromium and molybdenum contents to suit the environment the alloy must endure. Stainless steel's resistance to corrosion and staining, low maintenance,
Austenitic stainless steel corrosion). The higher nitrogen addition in 200 series gives them higher mechanical strength than 300 series. Other notable austenitic stainless steels are Type 309 and 310, which are utilized in high temperature applications greater than 800°C. Alloy 20 (Carpenter 20) is an austenitic stainless steel possessing excellent resistance to hot sulfuric acid and many other aggressive environments which would readily attack type 316 stainless. This alloy exhibits superior resistance to stress-corrosion cracking in boiling 20–40% sulfuric acid. Alloy 20 has excellent mechanical properties and the presence of niobium in the alloy minimizes the precipitation of carbides during welding. Austenitic stainless