Introduction to SUS304 stainless steel
Material SUS304 is a Japanese JIS standard and the most commonly used stainless steel, containing 18% Cr and 8% Ni. It can maintain good strength and heat resistance in high and low temperature environments, and also has good corrosion resistance, weldability, cold workability and mechanical properties in mild atmosphere.
Meaning of SUS304 material
SUS is the first letter of “Steel Use Stainless” written in English. The stainless steel number consists of three digits, the 300 series is austenitic stainless steel and the 400 series is ferritic or martensitic stainless steel.
Datasheet and specifications
The following are the technical sheets of the chemical composition and properties of SUS304, such as melting point, density, tensile strength, elongation, modulus of elasticity, specific heat, coefficient of thermal expansion, thermal conductivity, electrical resistivity, magnetic properties and so on. against.
Chemical composition of SUS304 stainless steel
The composition of SUS304 grade stainless steel is shown in table 1.
Table 1, composition of SUS304 stainless steel
| Chemical composition % | |||||||||
| Country (Region) | Standard | Steel Grade | C ≤ | Si ≤ | Mn ≤ | P ≤ | S ≤ | Cr | No |
| Japan | JIS G4303 | SUS304 | 0.08 | 1.00 | 2:00 | 0.045 | 0.030 | 6pm-8pm | 8:00am-10:50am |
Mechanical Properties of SUS 304
The following table shows the yield strength, tensile strength, elongation and hardness of SUS 304.
Table 2, mechanical properties of SUS 304
| Mechanical properties | ||||||||
| Country (Region) | Standard | Steel Grade | Diameter (d) in mm | Yield limit (N/mm2) | Tensile strength (N/mm2) | Stretching (%) | Hardness (HB) | Hardness (HV) |
| Japan | JIS G4303 | SUS304 | d≤180 | ≥ 205 | ≥ 520 | 40 | ≤ 187 | ≤ 200 |
Physical properties
Table 3, Physical properties of SUS 304 material
| Physical properties of SUS304 material | |
| Density (g/cm3) | 7.93 |
| Melting point (℃) | 1,400-1,450 |
| Specific heat (J/kg·℃) | 460-502 |
| Electrical resistivity (μΩ·m) (20℃) | 0.73 |
| Thermal expansion (10 -6 /K) | 16.3 (20-100°C) |
| 17.8 (20-300°C) | |
| 18.4 (20-500°C) | |
| Thermal conductivity (W/m·K) | 16.8 (100°C) |
Magnetic
SUS304 material is non-magnetic, but may be slightly magnetic due to cold working.
Corrosion resistance
The reason why SUS 304 stainless steel has excellent resistance to atmospheric corrosion is due to the formation of a chromium passivation film on its surface. But when SUS 304 is in a hot chloride environment, it corrodes even faster than unalloyed carbon steel.
Heat treatment
SUS304 stainless steel solution heat treatment is from 1010 ℃ to 1150 ℃ in rapid cooling method.
Welding
SUS 304 stainless steel has good weldability and can be welded by the usual welding method without heat treatment before welding.
However, the welding of SUS 304 material is also insufficient: after welding large steel parts, it is sensitive to intergranular corrosion in a chlorine-containing medium. In this case, the SUS304L with the lowest carbon content should be selected.
Forms
SUS304 stainless steel is widely used in medical areas (such as surgical instruments, testing instruments), food areas (such as kitchen utensils and tableware), architectural decoration and works of art (such as metal curtains, drilling nets, metal facades ) and electronic products (such as mobile phones and laptop case, kettle), daily necessities (such as scissors, water cups, etc.)
Equivalence
JIS SUS304 material equivalent to ASTM AISI, European EN (Germany DIN EN, British BSI, French NF…), ISO and Chinese standard GB.
| Equivalent material SUS304 | |||||||||
| Japan | USA | European Union | ISO | China | |||||
| Standard | Note | Standard | Note (UNS) | Standard | Steel Name (Steel Number) | Standard | Note | Standard | Note |
| JIS G4304 | SUS304 | AISI; ASTM A240/A240M; A276/A276M |
AISI304 (S30400) | EN 10088-3; EN 10088-1 |
X5CrNi18-10 (1.4301) | ISO 15510 | X5CrNi18-10 | GB/T 20878; GB/T 1220; GB/T 3280 |
06Cr19Ni10; 0Cr18Ni9 (old designation) |
