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HYUNDAI BNG STEEL

Classification

Stainless steel consists of 400 series (Fe-Cr series) and 300 series (Fe-Cr-Ni series). replace textreplace text

Stainless steel STS Classification table
Stainless steel
Fe-Cr-Ni series (300 series) Fe-Cr series (400 series)
Ferrite series Martensite series Austenite series Anomaly Series Precipitation Hardening Series
  • Body Centered Cubic (BCC)
  • Heat treatment can’t harden ferrite series.
  • Representative steel: STS430
  • Ferromagnetism at normal temperature
  • Martensite series has low corrosion resistance and high strength
  • It is generated from austenite structure by transformation of martensite caused by cooling
  • Representative steel: STS 410
  • Face Centered Cubic (FCC)
  • Heat treatment can’t harden austenite series, while processing can harden
  • Non magnetic (magnetic after processing)
  • Representative steel: STS304
  • Blended structure of austenite and ferrite phase at normal temperature
  • High strength and fine crystallization
  • It supplements low resistance and toughness of ferrite series for local etching
  • Representative steel: STS329J1
  • Steel which has improved hardness by precipitating metal compound, such as Cu, Al, Ti, Nb, using seasoning after heat treatment
  • Representative steel: STS630
Classification by Steel Type
Stainless steel has different contents of chemical component and mechanical property(tensile strength), as well as nature, feature and use according to steel type.

Austenite series

Austenite series Classification by Steel Type table
Type Composition Property and Feature Use
201 16Cr-9Mn-1Ni It is representative steel for 301 which has magnetic by cold working. Tableware, Decoration pipe, Construction material
202 17Cr-6.5Mn-4.5Ni It is austenite series steel that replaces high priced Ni with Mn. It is used as low quality product in Asia by replacing 304. Tableware, Decoration pipe, Construction material
301 17Cr-7Ni It is austenite series which have low stability and less Cr, Ni than standard 304 so that processed organic martensite is easily generated. Its tensile strength and hardness are improved by cold working. It is non magnetic under annealing while it becomes magnetic after cold working. Part of automobile, Belt conveyor bolt, Nut, Spring
301L 17Cr-7Ni-0.1N-low C It has improved intergranular corrosivity of weld zone for high strength 301 steel and strength by adding N. Frame and exterior for train
302 18Cr-8Ni-0.1 C It is used for press processing and has more C than 304, so that it has less corrosion resistance than 304 and has workability between 301 and 304. Construction material
304 18Cr-8Ni 304, the most widely used steel in market, has strong mechanical property, including good corrosion resistance, heat resistance and low temperature strength, by adding Ni and it is magnetic and can’t be hardened by heat treatment. Tableware and kitchen products, Pipe, Water heater, Boiler, Bath, Muffler, Construction material
304L 18Cr-9Ni-low c It has lower C than 304 so that shows similar corrosion resistance. After welding, it acquires corrosion resistance without heat treatment, since it has strong resistance for corrosion on grain boundary. Area where 304 is not available because of corrosion on grain boundary or parts which is not available for heat treatment, including parts for chemical industry, coal industry, petroleum industry
316 18Cr-12Ni-2.5Mo It is Mo(2~3%) added steel to improve pitting resistance for salt, showing strong creep strength and non magnetic at high temperature. Paper, chemistry, plastic, fertilizer, picture, food industry and construction material used in coast
316L 18Cr-12Ni-2.5Mo-low C It reduces C portion of 316 steel to give intergranular ability to 316 steel Product which is not available for heat treatment after welding
321 18Cr-8Ni-Ti It prevents corrosion on grain boundary by adding Ti in 304 steel to use for corrosion sensitive area on grain boundary, at 450~900°C. Airplane pipe, Boiler cover
347 18Cr-8Ni-Nb It restrains precipitation of crystallized grain boundary for used carbide to improve resistance for corrosion on grain boundary and heat resistance after welding. Identical with 321

Ferrite series

Ferrite series Classification by Steel Type table
Type Composition Property and Feature Use
409L 11Cr-Ti -low (C,N) It is fully ferrite STS steel that Ti is added to improve intergranular corrosivity at ordinary temperature. It has good weldability and toughness at low temperature and has better moldability than 403. Pipe for automobile
410L 13Cr-low C It improves weldability, flexibility, workability and high temperature resistance oxidizability by reducing C. Pipe for automobile, Combustor in boiler
430 18Cr 430, representative steel of Cr series, has lower price than austenite series and better workability and corrosion resistance, while it is not available for drawing which has sharp curve and 430 can’t be hardened by heat treatment. Part of automobile, Washer, Construction interior, Electric appliances, tanks
430LX, 430J1L, 430CuN 18Cr-Ti,Ti or Nb-low C It improves workability and weldability by adding Ti, Nb and reducing C. Tank for seawater, Water heater, Sanitary fixture, Bicycle RIM
434 18Cr-1Mo It has better salt resistance than 430 by adding Mo. Exterior for automobile
436L 18Cr-1Mo -Ti, Nb, Zr-extremely low (C,N) It improves workability and weldability by reducing C and N to 434 or by adding Ti, Nb or Zr solely or in combination. Construction exterior, Part of automobile, Kitchen product, Water heater, Water supply device
439L 18Cr-Ti It is ferrite series STS, which Cr and Ti are added and C is reduced, to improve workability, corrosion resistance and weldability. Exhauster
443CT 21Cr-Ti-Cu It is ferrite series STS, which has equal corrosion resistance to 304 by adding Cr up to 21%. It adds Ti and Cu to improve intergranular corrosivity and moldability. Construction material, Kitchen product, Part of automobile
444 19Cr-2MoTi, Nb, Zr -extremely low (C,N) It improves corrosion resistance by adding Mo. Storage tank, Solar water heater, Restraint of stress corrosion

Martensite series

Martensite series Classification by Steel Type table
Type Composition Property and Feature Use
410 13Cr 410, representative steel of martensite series, has cost advantage and good workability but it is not suitable for corrosion area. It can’t be hardened by heat treatment. Low end blade, Machine part, Petroleum refining device, Bolt, Nut, Pump, Shaft
420J1 13Cr-0.2C It has high hardness and higher corrosion resistance than 13Cr under quenching. Turbine blade
420J2 13Cr-0.3C It shows better hardness than 420J1 after quenching. Blade, Nozzle, Valve, Roller
440A 18Cr-0.7C It has good quenching hardenability and toughness. Knife, Cauge, Bearing
Chemical Compositions
Stainless steel is classified by percentage of iron Chemical Composition (C, S, Mn, P, S, Ni, Cr, etc).

Austenite series

Austenite series Chemical Compositions table
Type Symbol Chemical Composition
C Si Mn P S Ni Cr Others
201 BNG201 ≤0.10 ≤0.75 8.00~10.00 ≤0.060 ≤0.030 1.00~2.00 13.00~17.00 Less than N 0.20,
Cu 1.50 ~ 2.00
STS201 Type201 ≤0.15 ≤1.00 5.5~7.5 ≤0.060 ≤0.030 3.5~5.5 16.00~18.00 Less than N 0.25
202 BNG202 ≤0.10 ≤1.00 3.00~9.00 ≤0.070 ≤0.030 3.00~6.00 13.00~18.00 Less than N 0.20,
Cu 1.30 ~ 3.50
STS202 Type202 ≤0.15 ≤1.00 7.5~10.0 ≤0.060 ≤0.030 4.0~6.0 17.00~19.00 Less than N 0.25
301 STS301 ≤0.15 ≤1.00 ≤2.00 ≤0.045 ≤0.030 6.00~8.00 16.00~18.00 -
301L STS301L ≤0.303 ≤1.00 ≤2.00 ≤0.045 ≤0.030 6.00~8.00 16.00~18.00 Less than N 0.20
304 STS304 ≤0.08 ≤1.00 ≤2.00 ≤0.045 ≤0.030 8.00~10.50 18.00~20.00 -
304L STS304L ≤0.030 ≤1.00 ≤2.00 ≤0.045 ≤0.030 9.00~13.00 18.00~20.00 -
304J1 STS304J1 ≤0.08 ≤1.00 ≤3.00 ≤0.045 ≤0.030 6.00~9.00 15.00~18.00 Cu 1.00~3.00
305 STS305 ≤0.12 ≤1.00 ≤2.00 ≤0.045 ≤0.030 10.50~13.00 16.00~18.00 -
316 STS316 ≤0.08 ≤1.00 ≤2.00 ≤0.045 ≤0.030 10.00~14.00 16.00~18.00 Mo 2.00~3.00
316L STS316L ≤0.030 ≤1.00 ≤2.00 ≤0.045 ≤0.030 12.00~15.00 18.00~20.00 Mo 2.00~3.00
321 STS321 ≤0.08 ≤1.00 ≤2.00 ≤0.045 ≤0.030 9.00~13.00 18.00~20.00 More than Ti 5xC%

Ferrite series

Ferrite series Chemical Compositions table
Type Symbol Chemical Compositions
C Si Mn P S Cr Others
409L STR409L1) ≤0.303 ≤1.00 ≤1.00 ≤0.040 ≤0.030 10.50~11.75 More than Ti 6xC% ~ 0.75
430 STS430 ≤0.12 ≤0.75 ≤1.00 ≤0.040 ≤0.030 16.00~18.00 -
430J1L STS430J1L ≤0.025 ≤1.00 ≤1.00 ≤0.040 ≤0.030 16.00~20.00 Less than N 0.025, Cu 0.30 ~ 0.80 Ti, Nb, Zr or combination of the above 8x(C%+N%) ~ 0.80
436L STS436L ≤0.025 ≤1.00 ≤1.00 ≤0.040 ≤0.030 16.00~19.00 Mo 0.75~1.50, Less then N 0.025, Ti, Nb, Zr or combination of the above 8x(C%+N%)~0.80
439L STS439 ≤0.030 ≤1.00 ≤1.00 ≤0.40 ≤0.030 17.00~20.00 Less than N 0.030, Ti, Nb or combination of the above 8x(C%+N%)~0.80
444 STS444 ≤0.025 ≤1.00 ≤1.00 ≤0.040 ≤0.030 17.00~20.00 Less than N 0.025, Mo 1.75~2.50, Ti, Nb, Zr or combination of the above 8x(C%+N%) ~ 0.80
443CT BNG443CT ≤0.025 ≤1.00 ≤1.00 ≤0.040 ≤0.03 20.00~23.00 Less than –N 0.025, Cu 0.3~0.8, Less than Ti 0.80
445NF BNG445NF ≤0.025 ≤1.00 ≤1.00 ≤0.040 ≤0.030 20.00~23.00 Cu 1.00~3, Less than N 0.020, Cu 0.3~0.7, Less than Ti 0.50

1) Heat Resistance Steel (KS D 3732)

Martensite series

Martensite series Chemical Compositions table
Type Symbol Chemical Compositions
C Si Mn P S Ni Cr Others
410 STS410 ≤0.15 ≤1.00 ≤1.00 ≤0.040 ≤0.030 ≤0.60 11.50~13.50 -
420J1 STS420J1 0.16~0.25 ≤1.00 ≤2.00 ≤0.040 ≤0.030 ≤0.60 12.00~14.00 -
420J2 STS420J2 0.26~0.40 ≤1.00 ≤2.00 ≤0.040 ≤0.030 ≤0.60 12.00~14.00 -