300 series: chromium-nickel austenitic stainless steel
301: good ductility, used for molding products. Can also be hardened quickly by mechanical processing. Weldability is good. Wear resistance and fatigue strength is better than 304 stainless steel.
302: corrosion resistance with 304, due to the relatively high carbon content and therefore better strength.
303: by adding a small amount of sulfur and phosphorus to make it easier to cut and process than 304.
304: general type; that is, 18/8 stainless steel. Products such as: corrosion-resistant containers, cutlery, furniture, railings, medical equipment. The standard composition is 18 % chromium and 8 % nickel. The standard composition is 18 % chromium and 8 % nickel. It is a non-magnetic stainless steel that can not be altered by heat treatment to change its metallurgical structure. 0Cr18Ni9 is the GB grade.
304 L: the same characteristics as 304, but with lower carbon so it is more corrosion-resistant and easy to heat-treat, but mechanically poorer. It is suitable for welding and not easy to heat-treat products.
304 N: the same characteristics as 304, is a stainless steel containing nitrogen, nitrogen is added to improve the strength of the steel.
309: better temperature resistance than 304, temperature resistance up to 980 ℃.
309 S: with a large amount of chromium, nickel, so heat-resistant, good oxidation resistance, products such as: heat exchangers, boiler components, injection engines.
310: High-temperature oxidation resistance is excellent, the maximum operating temperature of 1200 ℃.
316: after 304, the second most widely used steel, mainly used in the food industry, watch jewelry, pharmaceutical industry and surgical equipment, the addition of molybdenum to obtain a corrosion-resistant special structure. The addition of molybdenum gives it a special structure that resists corrosion, and it is also used as a "marine steel" due to its better resistance to chloride corrosion compared to 304, while SS316 is commonly used in nuclear fuel recovery devices. 18/10 grade stainless steel is usually in line with this application level as well.
316 L: Low carbon and therefore more resistant to corrosion, easy to heat treat, products such as: chemical processing equipment, nuclear power generators, refrigerant storage lees.
321: Similar properties to 304 except that the addition of titanium reduces the risk of corrosion in weld seams.
347: The addition of the stabilizing element niobium makes it suitable for welding aerospace parts and chemical equipment.