Stainless steel

Stainless steel is often divided into martensitic steel, ferritic steel, austenitic steel, austenitic ferritic (duplex) stainless steel and precipitation hardening stainless steel, etc. In addition, according to the composition can be divided into: chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel

According to the composition can be divided into Cr series (400 series), CR-Ni series (300 series), CR-Mn-Ni (200 series), heat-resistant chromium alloy steel (500 series) and precipitation hardening series (600 series).

200 Series: Chrome-Manganese-nickel

201,202, etc. : Manganese instead of nickel, poor corrosion resistance, widely used as a cheap substitute for 300 series in China

300 Series: Chromium-nickel austenitic stainless steel

301: Good ductility, used for molding products. It can also be quickly hardened by machining. Good weldability. The wear resistance and fatigue strength are better than 304 stainless steel.

302: Corrosion resistance is the same as 304, and the strength is better because the carbon content is relatively high.

303: By adding a small amount of sulfur and phosphorus to make it easier to cut than 304.

304: general purpose model; 18/8 stainless steel. Products such as: corrosion resistant containers, tableware, furniture, railings, medical equipment. The standard ingredient is 18% chromium and 8% nickel. Stainless steel that is non-magnetic and cannot change its metallographic structure by heat treatment. The GB brand is 06Cr19Ni10.

304 L: the same characteristics as 304, but low carbon, so more corrosion resistance, easy heat treatment, but poor mechanical properties for welding and not easy to heat treatment products.

304 N: With the same characteristics as 304, it is a nitrogenous stainless steel, and nitrogen is added to improve the strength of steel.

309: Compared with 304 has better temperature resistance, temperature resistance up to 980℃.

309S: With a large amount of chromium, nickel, so good heat resistance, oxidation resistance, products such as: heat exchanger, boiler components, jet engine.

310: Excellent high temperature oxidation resistance, maximum operating temperature 1200℃.

316: After 304, the second most widely used steel grade, mainly used in the food industry, watch jewelry, pharmaceutical industry and surgical equipment, adding molybdenum element to make it obtain a special structure resistant to corrosion. Because it has better resistance to chloride corrosion than 304, it is also used as "Marine steel". SS316 is commonly used in nuclear fuel recovery units. Grade 18/10 stainless steel is also usually suitable for this application level.

316L: Low carbon so more corrosion resistance, easy heat treatment, products such as: chemical processing equipment, nuclear power generators, refrigerant storage tank.

321: In addition to the addition of titanium to reduce the risk of corrosion of the material weld, other properties are similar to 304.

347: Adding stabilizing element niobium, suitable for welding aviation equipment parts and chemical equipment.

400 series: Ferritic and martensitic stainless steel, no manganese, can replace 304 stainless steel to a certain extent

408: Good heat resistance, weak corrosion resistance, 11% Cr, 8% Ni.

409: Cheapest model (Anglo-American), commonly used as an automobile exhaust pipe, ferritic stainless steel (chromium steel).

410: Martensite (high strength chromium steel), good wear resistance, poor corrosion resistance.

416: The addition of sulfur improves the processing performance of the material.

420: "cutting tool grade" martensitic steel, similar to Brinell high chromium steel this earliest stainless steel. Also used in surgical knives, can be made very bright.

430: Ferritic stainless steel, used for decoration, such as car accessories. Good formability, but poor temperature resistance and corrosion resistance.

440: high-strength cutting tool steel, slightly higher carbon content, after appropriate heat treatment can obtain high yield strength, hardness can reach 58HRC, belongs to the hardest stainless steel. The most common example is the "razor blade". There are three common models: 440A, 440B, 440C, and 440F (easy to process).

500 series: Heat-resistant chrome alloy steel.

600 Series: Martensitic precipitation-hardened stainless steel.