SUS430 vs. SUS304 stainless steel: Corrosion resistance
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When choosing the right stainless steel for a specific application, two commonly used grades are SUS430 (also known as 430 stainless steel) and SUS304 (also known as 304 stainless steel). Both are widely used in a variety of industries, but they differ significantly in terms of corrosion resistance, strength, and versatility.
In this article, we will focus on comparing SUS430 vs. SUS304 stainless steel with a particular emphasis on their corrosion resistance, helping you decide which material is best for your specific application.
What is SUS304 stainless steel?
SUS304 is a popular Japanese (JIS standard) austenitic stainless steel, essentially the equivalent of American SS304, known for its excellent balance of corrosion resistance, strength, and formability due to its composition of about 18% chromium and 8% nickel, often called "18/8" stainless steel, making it ideal for food equipment, sinks, and architectural uses.
What is SUS430 stainless steel?
SUS430 is a ferritic stainless steel (part of the 400 series) known for good corrosion resistance, excellent formability, and affordability, primarily due to its chromium content (around 17%) and low nickel (under 0.5%), making it magnetic and suitable for household appliances, automotive trim, and kitchenware where high strength isn't critical but appearance and corrosion resistance are.
Corrosion Resistance: SUS430 vs. SUS304
SUS430 is a ferritic stainless steel, and its corrosion resistance is moderate compared to austenitic stainless steels like SUS304. It contains chromium (16-18%), which provides resistance to oxidation and mild corrosion, but its resistance to chlorides (salt) is limited, making it less suitable for harsh environments. SUS304 is an austenitic stainless steel, and due to its higher nickel content (8-10%) and chromium content (18-20%), its corrosion resistance is far superior to that of SUS430.
304 VS. 430 Stainless Steel Chemical Composition
| Grade | C | Si | Ni | Mn | P | S | N | Cr |
|---|---|---|---|---|---|---|---|---|
| 304 | 0.07 | 1.00 | 8.0 - 10.5 | 2.00 | 0.045 | 0.015 | 0.10 | 17.5 - 19.5 |
| 430 | 0.08 | 1.00 | - | 1.00 | 0.040 | 0.015 | - | 16.0 - 18.0 |
304 VS. 430 Stainless Steel:Mechanical properties
| Property | SUS430 (430 Stainless Steel) | SUS304 (304 Stainless Steel) |
|---|---|---|
| Material Type | Ferritic Stainless Steel | Austenitic Stainless Steel |
| Magnetic | Magnetic | Non-Magnetic |
| Tensile Strength | 480 MPa (min) | 520 MPa (min) |
| Yield Strength | 205 MPa (min) | 205 MPa (min) |
| Elongation | ≥ 22% | ≥ 40% |
| Applications | Automotive, Kitchen, Appliances | Food Processing, Medical, Marine |
SUS430 vs. SUS304 Stainless Steel: Magnetic Properties
SUS430 (430 stainless steel) is magnetic due to its ferritic crystal structure. This makes it suitable for applications where magnetic properties are required, such as in induction cooking or for magnetic testing. On the other hand, SUS304 (304 stainless steel) is non-magnetic because it has an austenitic structure. While 304 stainless steel can exhibit slight magnetism when cold worked, it is typically not magnetic, making it unsuitable for applications that require magnetic attraction.
SUS430 vs. SUS304 Stainless Steel: Machinability
In terms of machinability, SUS430 is generally easier to machine compared to SUS304. This is because SUS430 is a ferritic stainless steel, which has a lower work hardening rate and a more stable structure when subjected to cutting. This results in faster machining speeds and less tool wear. SUS304, being an austenitic stainless steel, tends to work-harden more quickly during machining, making it more difficult to process and requiring more power and precaution to prevent tool damage.
304 vs 430 stainless steel food grade
For food-grade applications, 430 stainless steel is a more economical magnetic alternative, but it has poorer corrosion and acid resistance. It is best suited for dry, less corrosive environments or electrical decorative parts, as prolonged contact with salty/acidic foods will corrode 430 stainless steel. Although both can be used in food processing, 304 stainless steel offers better durability and safety under various conditions, while 430 stainless steel should avoid contact with acidic or salty foods during use.
If you have project requirements for SUS304 or SUS430 stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. We can process the material into various practical product forms, including sheets, coils, tubes, bars, and wires. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.
