Stainless Steel

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Outline of STS(Stainless Steel)

STS(Stainless Steel)

  • Alloy steel with Cr added over 13% for corrosion resistance
  • When CrDL added over 12%, Cr2, O2 film is formed on the surface of Passive State Metal
  • Various alloys including Ni, Mo, N are added to improve corrosion resistance, workability and properties

Characteristics of stainless steel

Characteristics of stainless steel can be divided into quality and physical properties: quality characteristics include corrosion resistance, weldability, creep strength, molding workability.
The most important characteristic is corrosion resistance, which is, unlike regular carbon steel, forms oxide film on the surface of Passive State Metals, which contributes to excellent corrosion resistance.
Corrosion is depending on Cr content in Fe-Cr type atmosphere. If Cr content is over 15%, it suggests excellent corrosion resistance.
The corrosion resistance according to the type of steel somewhat varies according to the corrosion environment and the corrosion type, but in general, the corrosion resistance of Austenite type steel is the best, and the corrosion resistance is decreased in order of Ferrite type and Martensite type.
For Austenite Product Specification, hardening is done by cold working, but the workability is limited. As work hardening increases, formability deteriorates.


Product Specification Properties and characteristics Application field
301 Less Cr and Ni than those of standard type 304. It is Austenite type with low stability which causes strain-induced Martensite. The tensile strength and hardness are increase by cold working. In annealing state, it is non-magnetic while it is magnetic after cold working. Belt Conveyor Bolt, Nut, Spring, Vehicle parts
301L It has improved intergranular corrosion resistance on the welding part of high strength 301 steel; strength deterioration due to C decrease is supplemented by adding N. Frame and exterior for railway vehicles
304 Widely used Product Specification. It contains Ni therefore shows excellent corrosion resistance and heat resistance. It has low temperature strength and good mechanical property. Not hardened by heating; and non-magnetic. Bath, Boiler, ,Iinterior/exterior building materia, , Mufflerl, Plumbing, Tableware and kitchen appliances, Water heater
304L It has less C than 304; similar corrosion resistance but intergranular resistance is great after welding therefore it has corrosion resistance without heat treatment. Part where 304 is not durable against intergranular corrosion; Chemical, Coal, Petroleum parts that cannot be treated with heat
316 2~3% Mo added to enhance pitting resistance against seawater and salt. It has non-magnetic property with excellent creep strength at high temperature. Building material for seaside, Chemical, Fertilizer photo, Food, Paper, Synthetic resin
316L It prevents intergranular corrosion by adding Ti to 316 steel; good for intergranular corrosion of 450~900℃ in sensitization section Aircraft piping, Boiler cover
321 Strong against intergranular corrosion Nuts, Machinery parts, Springs etc.


Product Specification Properties and characteristics Application field
409L Addition of Ti improves intergranular corrosion resistance; fully ferrite STS at high temperature and room temperature by low C, N. Excellent weldability, low temperature toughness; better formability compared to 430 Automobile exhaust pipe
410L Great weldability, flexibility, workability, high temperature resistance, oxidizing property by reducing C Automobile exhaust pipe, Boiler combustion chamber
430 The representative Cr-type steel; the most common type; less expensive than Aus-type; good workability and corrosion resistance; but difficult to use for severe curve or drawing. It has magnetic property that is not hardened by heat treatment Automobile parts, Electric device, Interior building material, Various tanksWashing machine
436L It is a Product Specification in which C and N are reduced from 434; and Ti, Nb and Zr are individually added or added in mix; excellent workability and weldability. Automobile parts, Exterior building material, Hot water, Kitchen utensils, Water supply equipment
444 Product Specification with improved corrosion resistance by increasing Mo compared to 436. Low-temperature bath, Solar water heater, Stress corrosion inhibitor, Water tank


Product Specification Properties and characteristics Application field
410 Representative Martensite Product Specification. Price is affordable but not suitable for corrosive environment. Excellent workability. Hardened by heat treatment. Bolts, Buts, Low-priced blade, Machine part, Oil refining equipment, Pumps, Shaft
420J1 Great hardness in quenching. Better corrosion resistance than that of 13Cr Turbine blade
420J2 Better hardness in quenching than that of 420J1 Blade, Nozzle, Valve, Bar