General Properties
Alloy 304L a T-300 series stainless steel austenitic, which has a minimum of 18% chromium and 8% nickel. Type 304L has a carbon maximum is 0.030. It is the standard “18/8 stainless” that is commonly found in pans and cooking tools. Alloys 304L is the most versatile and widely used alloy in the stainless steel family. Ideal for a wide variety of home and commercial applications, Alloys 304L exhibits excellent corrosion resistance and has a high ease of fabrication, outstanding formability. The austenitic stainless steels are also considered to be the most weldable of the high-alloy steels and can be welded by all fusion and resistance welding processes.
Specifications: UNS S30403
Applications:
Alloy 304L Stainless Steel is used in a wide variety of home and commercial applications, including:
Food processing equipment, particularly in beer brewing, milk processing, and wine making
Kitchen benches, sinks, troughs, equipment, and appliances
Architectural trim and molding
Automotive and aerospace structural use
Construction material in large buildings
Chemical containers, including for transport
Heat exchangers
Nuts, bolts, screws, and other fasteners in the marine environment
Dyeing industry
Woven or welded screens for mining, quarrying & water filtration
Standards:
ASTM/ASME: S30403
EURONORM: 1.4303
AFNOR: Z2 CN 18.10
DIN: X2 CrNi 19 11
Corrosion Resistance:
Resistance to corrosion in oxidizing environments is a result of the 18 to 19% chromium that the 304 alloys contain.
Resistance to moderately aggressive organic acids is a result of the 9 to 11% nickel that the 304 alloys contain.
At times, alloy 304L may show a lower corrosion rate than the higher carbon Alloy 304; otherwise, the 304, 304L, and 304H may be considered to perform uniformly in most corrosive environments.
Alloy 304L is preferred for use in environments sufficiently corrosive to cause intergranular corrosion of welds and heat-affected zones on susceptible alloys.
Heat Resistance:
Good oxidation resistance in intermittent service to 1600°F and in continuous service to 1690°F.
Continuous use of 304 in the 800-1580°F range is not recommended if subsequent aqueous corrosion resistance is important.
Grade 304L is more resistant to carbide precipitation and can be heated into the above temperature range.
Properties of 304 Alloy
Welding Characteristics:
Excellent welding properties; post-weld annealing is not required when welding thin sections. Two important considerations in producing weld joints in the austenitic stainless steels are:
preservation of corrosion resistance
avoidance of cracking
Processing – Hot Forming:
To forge, heat uniformity to 2100 / 2300 °F
Do not forge below 1700 °F
Forging can be air cooled without danger of cracking
Processing – Cold Forming:
Its austenitic structure allows it to be deep-drawn without intermediate annealing, Making this the stainless steel grade of choice in the manufacturing of sinks, hollow-ware and saucepans.
These grades work harden rapidly. To relieve stresses produced in severe forming or spinning, parts should be full annealed or stress relief annealed as soon as possible after forming.
Machinability:
The use of chip breakers is advised since the chips can be stringy. Stainless steel work harden rapidly, heavy positive feeds, sharp tooling, and a rigid set-up should be used.of cut below the work-hardened layer resulting from the previous passes.
|
C |
Mn |
Si |
P |
S |
Cr |
Ni |
N |
304L |
0.03max |
2.0max |
0.75max |
0.45max |
0.03max |
min: 18.0 max: 20.0 |
min: 8.0 max: 12.0 |
0.10 max |
Grade |
Tensile Strength ksi (min) |
Yield Strength 0.2% ksi (min) |
Elongation % |
Hardness (Brinell) MAX |
Hardness (Rockwell B) MAX |
304L |
70 |
25 |
40 |
201 |
92 |
Density |
Thermal Conductivity |
Electrical |
Modulus of |
Coefficient of |
Specific Heat |
Melting |
at 68°F: 0.285 |
9.4 at 212°F |
28.3 at 68°F |
28 |
9.4 at 32 – 212°F |
0.1200 at 68°F to 212°F |
2500 to 2590 |
|
12.4 at 932 °F |
39.4 at 752°F |
|
10.2 at 32 – 1000°F |
|
|
|
|
49.6 at 1652 °F |
|
10.4 at 32 – 1500°F |
|
|
Surface treatment
Itme |
Surface finishing |
Surface finishing methods |
Main application |
NO.1 | HR | Heat treatment after hot rolling, pickling, or with treatment | For without the purpose of the surface gloss |
NO.2D | Without the SPM | Method of heat treatment after cold rolling, pickling surface roller with wool or eventually a light rolling a matte surface processing | General materials,building materials. |
NO.2B | After SPM | Giving No.2 processing materials appropriate method of cold light sheen | General materials, building materials ( most of the goods are processed ) |
BA | Bright annealed | Bright heat treatment after cold rolling , in order to be more shiny, cold light effect | Automotive parts, home appliances, vehicles, medical equipment, food equipment |
NO.3 | Shiny, coarse grain processing | The NO.2D or NO.2B processing timber No. 100-120 polishing abrasive grinding belt | Building materials, kitchen supplies |
NO.4 | After CPL | The NO.2D or NO.2B processing timber No. 150-180 polishing abrasive grinding belt | Building materials, kitchen supplies, vehicles, medical equipment, food equipment |
240# | Grinding of fine lines | The NO.2D or NO.2B processing timber 240 polishing abrasive grinding belt | Kitchen appliances |
320# | More than 240 lines of grinding | The NO.2D or NO.2B processing timber 320 polishing abrasive grinding belt | Kitchen appliances |
400# | Close to BA luster | The MO.2B timber 400 polishing wheel polishing method | Building materials, kitchen utensils |
HL(hair lines) | Polishing line having a long continuous processing | In a suitable size ( usually mostly No. 150-240 grit ) abrasive tape for as long as the hair, having a continuous processing method of polishing line | The most common building materials processing |
NO.6 | NO.4 processing less than the reflection , the extinction | NO.4 processing material used for polishing Tampico brushing | Building materials, decorative |
NO.7 | Highly accurate reflectance mirror processing | No. 600 of the rotary buff with a polishing | Building materials, decorative |
NO.8 | Highest reflectivity mirror finish | Fine particles of abrasive material in order polishing , mirror polishing with a polishing | Building materials, decorative, mirrors |
Stainless steel international standard:
INTERNATIONAL STANDARD:
Approximate Comparative Table | |||||||||||
ASTM/ASME | ISO | USA | JAPAN | BRITAIN | GERMANY | FRANCE | SWEDEN | ITALY | INDIA | CNS | |
UNS No. | AISI | JIS | BS | WERKSTOFF DIN | NF | SIS | UNI | IS | |||
S20100 | A-2 | 201 | SUS201 | 1.4371 | X12CrMnNi1885 | Z12CMN17-07AZ | 201 | ||||
S20200 | A-3 | 202 | SUS202 | 284S16 | 202 | ||||||
S30100 | 14 | 301 | SUS301 | 301S21 | 1.431 | X12CrNi177 | Z11CN17-08 | 142331 | X12CrNi1707 | 10Cr17Ni7 | 301 |
S30200 | 12 | 302 | SUS302 | 302S25 | 1.43 | X12cRnI188 | Z12CN18-09 | 142332 | X10CrNiS1809 | 302 | |
S30300 | 17 | 303 | SUS303 | 303S21 | 1.4305 | X10CrNiS189 | Z8CNF18-09 | ||||
S30323 | 17a | 303Se | SUS303Se | 303S41 | Z10CNF18-09 | 142346 | X10CrNiS1809 | ||||
S30400 | 11 | 304 | SUS304 | 304S31 | 1.4301 | X5CrNi1810 | Z7CN18-09 | 142333 | X5CrNi1810 | 04Cr18Ni10 | 304 |
S30403 | 10 | 304L | SUS304L | 304S11 | 1.4306 | X2CrNi1911 | Z3CN18-10 | 142352 | X2CrNi1811 | 02Cr18Ni11 | 304L |
S30500 | 13 | 305 | SUS305 | 305S19 | 1.4303 | X5CrNi1812 | Z8CN18-12 | 305 | |||
S30900 | 309 | SUH309 | 309S24 | 1.4828 | Z12CN24-13 | X16CrNi2314 | |||||
S30908 | 309S | SUS309S | 309S16 | 309S | |||||||
S31000 | 310 | SUH310 | 310S24 | 1.4841 | Z12CN25-20 | 142361 | X6CrNi2520 | ||||
S31008 | H15 | 310S | SUS310S | 310S16 | 1.4845 | Z8CN25-10 | 142361 | X6CrNi2520 | 310S | ||
S31600 | 20 | 316 | SUS316 | 316S31 | 1.4401 | X5CrNiMo17122 | Z7CND17-11-02 | 142343 | X8CrNiMo1713 | 04Cr17Ni12Mo2 | 316 |
S31603 | 19 | 316L | SUS316L | 316S11 | 1.4404 | X2CrNiMo17132 | Z3CND17-12-02 | 142348 | X2CrNiMo1712 | 02Cr17Ni12Mo2 | 316L |
S31635 | 21 | 316Ti | SUS316Ti | 320S31 | 1.4571 | X6CrNiMoTi17122 | Z6CND17-12 | 142350 | 316Ti | ||
S31700 | 317 | SUS317 | 317S16 | 1.4436 | X5CrNiMo17133 | Z3CND19-15-04 | 142367 | 317 | |||
S32100 | 15 | 321 | SUS321 | 321S31 | 1.4541 | X6CrNiTi1810 | Z6CNT18-10 | 142337 | X6CrNiTi1811 | 04Cr18Ni10Ti20 | 321 |
S34700 | 16 | 347 | SUS347 | 347S31 | 1.455 | X6CrNiNb1810 | Z6CNNb18-10 | 142338 | X8CrNiNb1811 | 347 | |
S40300 | 403 | SUS403 | 403S17 | 1.4024 | X5Cr13 | Z12C13 | 142301 | 403 | |||
S40500 | 2 | 405 | SUS405 | 405S17 | 1.4002 | X6CrAl13 | Z8CA12 | X6CrAl13 | 405 | ||
S40900 | 1 Ti | 409 | SUH409 | 409S19 | 1.4512 | X6CrTi12 | Z8CNT12 | 409 | |||
S41000 | 3 | 410 | SUS410 | 410S21 | 1.4006 | X10Cr13 | Z13C13 | 142302 | X12Cr13 | 410 | |
S41600 | 7 | 416 | SUS416 | 416S21 | 1.4005 | X12CrS13 | Z11CF13 | X12CrS13 | |||
S42000 | 4 | 420 | SUS420J1 | 420S29 | 1.4021 | X20Cr13 | Z20C13 | 142304 | X30Cr13 | 420J1 | |
5 | SUS420J2 | 420S45 | 1.4028 | X30Cr13 | Z33C13 | 420J2 | |||||
S43000 | 8 | 430 | SUS430 | 430S17 | 1.4016 | X6Cr17 | Z8C17 | 142320 | X8Cr17 | 05Cr17 | 430 |
S43020 | 8C | 430F | SUS430F | 1.4104 | X4CrMoS18 | Z8CF17 | 142383 | X10CrS17 | |||
S43100 | 9b | 431 | SUS431 | 431S29 | 1.4057 | X20CrNi172 | Z15CN16-02 | 142321 | X16CrNi16 |