|Standard Ferritics - Applications|
Standard ferritics can undergo grain growth in the heat affected zone of weldments, which may adversely affect the mechanical properties in these zones. Applications involving welded standard ferritics are thus generally limited to a maximum thickness of 2.5mm. Edge welds are not recommended for applications using standard ferritics. Standard ferritics are unsuited for use in cryogenic applications as brittle fracture could occur at sub-zero temperatures.
U-40910 is a 12% chromium, titanium stabilised ferritic stainless steel. It is not as resistant to corrosion or high temperature oxidation as the higher alloyed stainless steels (for example U-430 or U-304), but is still superior to mild steel and low alloy corrosion resisting steels and most coated mild steels. U-409 finds its major application in silencers, catalytic converters and tubing for motor vehicle exhaust systems.
U-430 and U-430DDQ are low carbon plain chromium ferritic stainless steels. With 16% chromium, the steels have good corrosion resistance in moderately corrosive environments and good oxidation resistance at elevated temperatures.
They have excellent polishing characteristics and are therefore used in applications such as architectural trim. U-430 has good formability and corrosion resistance and this makes it suitable for applications such as catering equipment and kitchen sinks. U-430DDQ has even better formability and is thus used in deep drawing applications.
U-439 is a low carbon, titanium stabilised ferritic stainless steel. With 17% chromium, the steel has good corrosion resistance in moderately corrosive environments.
Titanium stabilisation improves the steel’s resistance to sensitisation in the weld heat affected zone. U-439 has similar formability to U-430DDQ. They are used in applications such as evaporator tube in the sugar industry and heat exchanger tubing.
U-1.4509 is a low carbon, dual stabilised ferritic stainless steel. With 18% chromium, the steel has good corrosion resistance in moderately corrosive environments and good oxidation resistance at elevated temperatures. U-1.4509 has good high temperature oxidation resistance and creep resistance and this makes it suitable for use in applications in automotive exhaust systems