SUS304 and SS304 both refer to 304 stainless steel, but their naming is different, the specific difference is as follows:
SUS304 is a Japanese Industrial Standard (JIS) designation commonly used in Japan and Asian markets.
SS304: is the abbreviation of "Stainless Steel 304", common in the European and American markets, is a common way of naming.
Chemical composition
The main chemical composition of SUS304 and SS304 is about 18% chromium (Cr) and about 8% nickel (Ni), which belong to 18-8 austenitic stainless steel. According to the Japan Industrial Standards Survey Association (JISC) issued "Cold rolled Stainless steel sheet, sheet steel and strip steel" (standard number: JIS G4305-2021) for example, SUS304 stipulates that the alloying element content is C≤0.08%, Si≤1.00%, Mn≤2.00%, P≤0.045%, S≤0.030%, Ni 8.00%-10.50%, Cr 18.00%-20.00%. The composition of SS304 is basically the same in actual production.
Stainless steel is widely used in modern industry and daily life, and SUS304 and SS304 are two common stainless steel models. While they look very similar, there are subtle differences in some ways. This article will compare these two kinds of stainless steel in detail from the aspects of chemical composition, performance characteristics, application fields, etc., to help you better understand their characteristics and application scenarios.
Chemical composition comparison
From the chemical composition point of view, the main components of SUS304 and SS304 include iron (Fe), chromium (Cr), nickel (Ni) and a small amount of carbon (C), manganese (Mn), silicon (Si) and other elements. The following are their typical chemical ranges:
|
The element
|
SUS304 (%)
|
SS304 (%)
|
|
Chromium (Cr)
|
18.0-20.0
|
18.0-20.0
|
|
Nickel (Ni)
|
8.0-10.5
|
8.0-10.5
|
|
carbon (C)
|
≤ 0.08
|
≤ 0.08
|
|
manganese (Mn)
|
≤ 2.00
|
≤ 2.00
|
|
silicon (Si)
|
≤ 1.00
|
≤ 1.00
|
As you can see from the table, their chemical composition is almost identical. However, due to differences in production processes and standards, the content of some trace elements may vary slightly. These differences usually do not significantly affect their performance, but may have an impact in certain circumstances.
Comparison of performance characteristics
1. Corrosion resistance
Both SUS304 and SS304 have excellent corrosion resistance, especially in oxidizing environments at room temperature, such as humid air, fresh water and weak acid environments. There is almost no difference in corrosion resistance between the two. However, in some special environments, such as high temperatures or high chloride concentrations, the specific performance may be slightly different, which is mainly related to the production process.
2. Mechanical properties
The mechanical properties of the two are very close, and both have good strength, toughness and ductility. They show good plasticity and weldability during processing, so they are widely used in the manufacture of complex shaped parts.
3. Heat resistance
Both SUS304 and SS304 have good heat resistance and can maintain high strength and oxidation resistance under high temperature environment. In general, they can withstand continuous use temperatures up to about 870°C and intermittent use temperatures of about 925°C.
4. Magnetism
Both are austenitic stainless steels that are almost non-magnetic in the annealed state. However, after cold processing, there may be a certain degree of magnetism, which has less impact on actual use.
Application field comparison
Due to the similarity of SUS304 and SS304 in performance, their application fields are roughly the same, mainly including the following aspects:
1. Food processing and storage equipment
Such as kitchen utensils, cutlery, sinks, storage tanks, etc. Their corrosion resistance and sanitary properties make them the material of choice for the food industry.
2. Architectural decoration
Such as stainless steel doors and Windows, guardrails, elevator decorative panels, etc., because of its beautiful appearance and strong oxidation resistance.
3. Chemical equipment
Such as pipes, containers, heat exchangers and other equipment, suitable for weak acid and weak alkali environment.
4. Automobile and mechanical parts
Including exhaust systems, springs, fasteners, etc., because of its good mechanical properties and heat resistance.
It should be noted that in the Japanese market, SUS304 is more common, while in the United States or international market, SS304 is more widely used. Therefore, when selecting materials, the appropriate model should be selected according to the project location and standard requirements.
Sum up
In general, SUS304 and SS304 are two very similar stainless steel materials, and they have almost no significant differences in chemical composition, performance characteristics and application fields. The main difference between the two is the nuances of the applicable standards and production processes. In practical applications, they can be used interchangeably in most cases, but when it comes to strict standards or special environments, the corresponding model should be selected according to specific needs.
