Stainless steel material classification

Stainless steel pipe according to the composition can be divided into Cr series (400 series), CR-Ni series (300 series), CR-Mn-Ni (200 series) and precipitation hardening system (600 series).

200 series - Chromium-nickel-manganese austenitic stainless steel 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----- has the same corrosion resistance as 304 and is better in strength due to its higher carbon content.

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

304----- is 18/8 stainless steel. The GB brand is 0Cr18Ni9. 309 - has better temperature resistance than 304.

316----- After 304, the second most widely used steel grade, mainly used in the food industry, pharmaceutical industry and surgical equipment, adding molybdenum element to give it a special structure resistant to corrosion. Because it has better resistance to chloride corrosion than 304 stainless steel pipe, it is also used as "Marine steel". SS316 is commonly used in nuclear fuel recovery units. Grade 18/10 stainless steel tubes are also typically compliant with this application level.

Model 321 - Similar in performance to 304 except for the addition of titanium which reduces the risk of corrosion in the weld of the material.

400 Series - Ferritic and martensitic stainless steel.

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 properties 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, for decorative purposes, e.g. for 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, is one of 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 pipe.