400 series stainless steel is an alloy of iron, carbon and chromium. Because it does not contain nickel, it is also called stainless iron. The specific introduction is as follows:

1. Main components and characteristics

Main components: The main components of 400 series stainless steel are iron (Fe) and chromium (Cr). The chromium content is usually between 11.5% and 18%. It also contains a small amount of carbon (C) and does not contain nickel (Ni).

Features

Physical and mechanical properties: Compared with carbon steel, the physical and mechanical properties of 400 series stainless steel are improved, and it has strong resistance to high temperature oxidation.
Magnetic properties: 400 series stainless steel has normal magnetic properties because it contains martensitic structure and iron elements.

Cost and price: Since it does not contain nickel, the cost of 400 series stainless steel is relatively low, so the price is also more affordable.

2. Common types and uses

Common types: 400 series stainless steel includes 410, 420, 430, 409L and other models. Among them, 430 stainless steel is used the most, with a chromium content of 18%; 410 and 420 stainless steel have a chromium content of 13%, and their main feature is high hardness.

Application areas: 400 series stainless steel is widely used in automobile exhaust pipes, elevators, washing machine inner drums, tableware, household appliances, medical equipment, water heaters, roof panels, curtain walls and power plant equipment. Specific examples include microwave oven inner tanks, washing machine inner drums, LCD display panels, tableware, kitchen sinks, balcony railings, roofing materials, etc.

3. Performance comparison

Corrosion resistance: The corrosion resistance of 400 series stainless steel is slightly worse than that of 304 series, but it still has a certain corrosion resistance and is suitable for general home kitchen environments. However, under the same chromium content, the corrosion resistance of 400 series stainless steel in oxidizing media such as atmosphere, fresh water and nitric acid is the same as that of 300 series stainless steel, and is better than that of 200 series stainless steel.

Hardness and toughness: 400 series stainless steel generally has a higher hardness, but relatively poor toughness. This makes 400 series stainless steel perform better in certain impact and wear environments, but not as well as 304 series in applications that require high toughness.

Processing performance: 400 series stainless steel has a higher hardness and is slightly more difficult to process, requiring the use of higher-strength tools and more efficient processing methods. At the same time, its welding performance is average, requiring special care and proper techniques to avoid cracks and deformation during welding.

4. Maintenance and use

Cleaning: 400 series stainless steel cookware should be cleaned with neutral detergent and avoid using chlorine-containing detergents to prevent corrosion. After cleaning, it should be wiped dry in time to prevent water stains from forming spots.

Precautions: 400 series stainless steel cookware should avoid long-term contact with strong acid and alkali foods, and avoid collision with hard objects when using to avoid scratches on the surface.

In summary, 400 series stainless steel occupies an important position in the market with its unique composition, characteristics, types, applications and relatively affordable prices.