Ferritic stainless steel is known for its high corrosion and oxidation resistance, but it has lower plasticity and toughness. Common grades include 409 and 430, which are mainly used in automotive and construction applications.
- Magnetic Properties: Ferritic stainless steel is magnetic.
- Thermal Expansion: The thermal expansion rate of ferritic stainless steel is low, with the degree of expansion being only 60% to 70% of that of austenitic stainless steel.
- High-Temperature Oxidation Resistance: Ferritic stainless steel has high resistance to high-temperature oxidation. Its surface oxidation tendency is lower than that of austenitic stainless steel, being 1.3 to 1.6 times less, and is more uniform.
- Creep Resistance: Ferritic stainless steel containing the stabilizing element niobium (Nb) has good creep resistance, with less strain under prolonged stress compared to austenitic stainless steel.
- Machinability: Ferritic stainless steel is easier to cut than austenitic stainless steel.
- Cold Processing Deformation: Ferritic stainless steel has a lower tendency for deformation in cold processing. Its deep drawing performance is better, but its swelling formation performance is not as good as that of austenitic stainless steel.
- Yield Strength: Ferritic stainless steel has high yield strength. Some high ferrochrome stainless steel can reach twice the yield strength of 304 stainless steel, though their extention rate is only about 60% of 304 stainless steel. Despite this, it remains acceptable for engineering applications.
- Corrosion Resistance: Ferritic stainless steel offers good uniform, spot, and crack corrosion resistance. Its corrosion resistance depends on the chromium (Cr) and molybdenum (Mo) content, often measured by the PRE (Pitting Resistance Equivalent, spot corrosion equivalent indication) value. In chlorinated water mediums, ferritic stainless steel shows no stress corrosion tendency.
- Cost: Ferritic stainless steel does not contain nickel (Ni), or only contains a small amount in special brands, making it relatively low-cost and less affected by fluctuations in nickel prices.
