It can be divided into Cr series (400 series), zhiCr-Ni series (300 series), daoCr-Mn-Ni (200 series), heat-resistant chromium alloy steel (500 series) and precipitation hardening series (600 series). Stainless steel is often divided into martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the state of organization. In addition, it can be divided into: chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel.

Stainless steel is a kind of material with brightness close to mirror surface, tough and cold to the touch. It is a relatively avant-garde decorative material with excellent corrosion resistance, formability, compatibility and toughness. It is used in heavy industry and light industry. , Daily necessities industry and architectural decoration industries.

Martensitic stainless steel is 13% Cr steel, commonly known as 420 stainless steel. 420 stainless steel is \"cutting tool grade\" martensitic steel, similar to the earliest stainless steel such as Brinell high chromium steel. 420 has a certain degree of wear resistance and corrosion resistance, high hardness, and its price is the lower category of stainless steel balls. It is suitable for working environments that generally require stainless steel. The improvement of standard martensitic steel contains additional elements such as nickel, molybdenum and vanadium. The corrosion resistance of martensitic stainless steel comes from \"chromium\", which ranges from 11.5 to 18%. The higher the chromium content, the higher the carbon content is required to ensure the formation of martensite during heat treatment.