1. Equivalent Grades for Various Standards
UNS: S30400
ASTM: TP304
EN: 1.4301
GB: 06Cr19Ni10
JIS: SUS304
2. 304 Chemical Composition (wt%, typical)
C ≤0.08%, Cr:18.00~20.00%, Ni:8.00~11.00%, Mn ≤2.00%, Si ≤1.00%, P ≤0.045%, S ≤0.030%, Fe balance.
3. Production Process
3.1 Smelting & Continuous Casting
Raw materials melted in EAF, refined in AOD furnace for precise composition control. Electromagnetically stirred continuous casting is adopted; slab surface is dressed to eliminate surface defects.
3.2 Hot Rolling Process
Slabs are heated to 1150~1250℃ for rough rolling and finish rolling into hot rolled coils. After annealing and mixed acid pickling, hot rolled pickled coils are obtained as raw feedstock for cold rolling.
3.3 Cold Rolling for Finished Strip
Hot pickled coil → degreasing → multi-pass cold rolling on precision cold mill → continuous bright annealing / solution annealing → pickling & passivation → skin pass leveling → slitting into narrow strips → inspection & packaging.
4. Surface Finishes
●2B: Matte grey finish, standard industrial surface after cold rolling & annealing, most widely used.
●BA (Bright Annealed): Mirror silver finish from bright annealing without oxidation, for precision stamping & decorative parts.
●HL (Hairline): Continuous linear brushed finish for architectural decoration.
●No.4: Short fine brushed finish for kitchen & sanitary products.
●No.1: Hot rolled black / pickled finish for thick gauge strip.
5. Product Features & Physical Properties
Physical & Mechanical Properties (annealed condition)
Yield strength ≥205MPa, Tensile strength ≥520MPa, Elongation ≥40%, HB ≤201. Coefficient of thermal expansion: ~17.2×10⁻⁶/℃; good thermal conductivity, non-magnetic after full annealing (slight magnetism after cold working).
Advantages
●Excellent atmospheric, freshwater and weak acid corrosion resistance without rust under regular indoor & mild outdoor environment.
●Outstanding ductility for deep drawing, bending, stamping and complicated forming.
●Superior weldability via TIG/MIG/ARC welding; easy machining and polishing.
●Balanced cost & performance, the most versatile general-purpose austenitic stainless steel.
6. Main Applications
●Kitchen & Catering: Kitchen utensils, sink, food processing equipment, water tank, tableware.
●Home Appliance: Inner liner of refrigerator, washing machine parts, heater components, microwave shells.
●Construction & Decoration: Elevator panel, door frame, handrail, decorative trim, curtain wall accessories.
●Mechanical & Hardware: Standard fasteners, springs, precision stamping parts, instrument casing.
●Petrochemical & Water Treatment: General chemical pipeline, low-pressure vessel, ordinary wastewater equipment.
●Electronics: Battery shell, shielding strip, precision hardware components.
