Stainless Steel Pipe Supplier Wenzhou Kaixin China
Simply put, SUS304 is 304 stainless steel. SUS is a Japanese material standard, and 304 stainless steel is a brand of stainless steel produced according to the American ASTM standard. 304 is equivalent to 0Cr19Ni9 (0Cr18Ni9) stainless steel in China, and Japan has also referred to it as SUS304 by the United States
Due to its high nickel content and austenitic single-phase structure at room temperature, it has high corrosion resistance compared to Cr13 stainless steel, high plasticity and toughness at low, room, and high temperatures, as well as good cold forming and weldability. However, the strength at room temperature is relatively low, with a greater tendency towards intergranular corrosion and stress corrosion, and poor machinability. Austenite does not undergo phase transformation during heating, therefore it cannot be strengthened through heat treatment. Heat treatment can only be carried out to improve the corrosion resistance of steel.
304 Stainless Steel
304 Stainless steel is an austenitic grade that can be severely deep drawn. This property has resulted in 304 being the dominant grade used in applications like sinks and saucepans.
Stainless Steel 304L
Type 304L is the low carbon version of 304 Stainless steel . It is used in heavy gauge components for improved weldability. Some products such as plate and pipe may be available as “dual certified” material that meets the criteria for both 304 and 304L.
Stainless Steel 304H
304H, a high carbon content variant, is also available for use at high temperatures.
Property data given in this document is typical for bar products covered by EN 10269:2013. ASTM, EN or other standards may cover products sold. It is reasonable to expect specifications in these standards to be similar but not necessarily identical to those given in this datasheet.
Application
304 stainless steel is widely used in the production of equipment and components with corrosion resistance and formability due to its excellent heat resistance. At present, 304 stainless steel has been widely used in industrial equipment such as food, chemical, atomic energy, and decoration fields, as well as household items, cabinets, indoor pipelines, water heaters, boilers, bathtubs, automotive accessories, medical appliances, building materials, chemistry, food industry, agriculture, and ship components.
304 Stainless Steel 1.4301 Finished Products Form
- Sheet
- Strip
- Bar
- Plate
- Pipe
- Tube
- Coil
- Fittings
Chemical Composition
| Element | Carbon (C) | Chromium (Cr) | Manganese (Mn) | Silicon (Si) | Phosphorous (P) | Sulphur (S) | Nickel (Ni) | Nitrogen (N) | Iron (Fe) |
| % Persent | 0.07 | 17.50 – 19.50 | Max2 | Max1 | Max0.045 | 0.015b) | 8.00 – 10.50 | 0.1 | Balance |
Chemical composition and properties of european equivalents (EN) for 304 (USA, AISI, ASTM, UNS):
X5CrNi18-10 (1.4301)
Equivalents of grade 304 stainless teel (USA: AISI, ASTM, UNS)
| EU EN | USA – | Germany DIN,WNr | Japan JIS | France AFNOR | England BS | Italy UNI | China GB | Sweden SS | Poland PN | Czechia CSN | Finland SFS | Austria ONORM | Russia GOST |
| X5CrNi18-10 (1.4301) | 304304N | 1.4301X5CrNi18-9 | SUS304 | X5CrNi18-10Z5CN18-09Z6CN18-09Z7CN18-09 | 304S15304S31 | X5CrNi18-10 | 0Cr18Ni9 | 23332333-02 | 0H18N9 | 17240 | 725 | X5CrNi18-10S | 08KH18N10 |
Corrosion Resistance of Stainless Steel X5CrNi18-10
Stainless steel 1.4301 has excellent corrosion resistance in a wide variety of environments and when in contact with different corrosive media. Pitting and crevice corrosion can occur in environments containing chlorides. Stress corrosion cracking can occur at temperatures over 60°C.
Heat Resistance of 08KH18N10 Stainless Steel
TP304 Stainless steel has good resistance to oxidation in intermittent service up to 870°C and in continuous service to 925°C. However, continuous use at 425-860°C is not recommended if corrosion resistance in water is required. In this instance 304L is recommended due to its resistance to carbide precipitation.
Where high strength is required at temperatures above 500°C and up to 800°C, grade 304H is recommended. This material will retain aqueous corrosion resistance.
Fabrication of Stainless Steel 304
Fabrication of all stainless steels should be done only with tools dedicated to stainless steel materials. Tooling and work surfaces must be thoroughly cleaned before use. These precautions are necessary to avoid cross contamination of stainless steel by easily corroded metals that may discolour the surface of the fabricated product.
Cold Working of Stainless Steel UNS S30400
304 Stainless steel readily work hardens. Fabrication methods involving cold working may require an intermediate annealing stage to alleviate work hardening and avoid tearing or cracking. At the completion of fabrication a full annealing operation should be employed to reduce internal stresses and optimise corrosion resistance.
Hot Working
Fabrication methods, like forging, that involve hot working should occur after uniform heating to 1149-1260°C. The fabricated components should then be rapidly cooled to ensure maximum corrosion resistance.
Heat Treatment
Stainless steel 304 cannot be hardened by heat treatment.
Solution treatment or annealing can be done by rapid cooling after heating to 1010-1120°C.
Machinability
304 has good machinability. Machining can be enhanced by using the following rules:
- Cutting edges must be kept sharp. Dull edges cause excess work hardening.
- Cuts should be light but deep enough to prevent work hardening by riding on the surface of the material.
- Chip breakers should be employed to assist in ensuring swarf remains clear of the work
- Low thermal conductivity of austenitic alloys results in heat concentrating at the cutting edges. This means coolants and lubricants are necessary and must be used in large quantities.
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50 mm) min | Hardness | |
|---|---|---|---|---|---|
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| 304 | 515 | 205 | 40 | 92 | 201 |
| 304L | 485 | 170 | 40 | 92 | 201 |
| 304H | 515 | 205 | 40 | 92 | 201 |
| Property | Value |
| Density | 8.00 g/cm3 |
| Melting Point | 1450 °C |
| Modulus of Elasticity | 193 GPa |
| Electrical Resistivity | 0.72 x 10-6 Ω.m |
| Thermal Conductivity | 16.2 W/m.K |
| Thermal Expansion | 17.2 x 10-6/K |
Welding of 304 Stainless Steel
Fusion welding performance for 304 Stainless steel is excellent both with and without fillers. Recommended filler rods and electrodes for 304 Stainless steel is grade 308 stainless steel. For 304L the recommended filler is 308L. Heavy welded sections may require post-weld annealing. This step is not required for 304L. Grade 321 may be used if post-weld heat treatment is not possible.