Class 5 ferritic stainless steel

Ferritic stainless steel is divided into five categories, of which three are non-standard grades and two are special grades. So far, the largest use and the most widely used are mainly concentrated in the standard grade.

Class 1 - Chromium content: 10%-14% Typical grades are 409 and 410L.

This type of steel has the lowest chromium content of all stainless steels, so it is the cheapest, and is best suited for use in environments where there is no corrosion or slight corrosion, allowing for localized slight rusting. Type 409 stainless steel was originally designed for use with mufflers in automotive exhaust systems (less corroded exterior). Type 410L stainless steel is commonly used in containers, buses and coaches, and has recently been used as the exterior frame of liquid crystal displays.

Class 2 - Chromium content: 14% to 18% typical grade 430.

It is the most widely used ferritic stainless steel, which contains high chromium and has good corrosion resistance, and most of its properties are similar to 304. In some applications, it can replace type 304 stainless steel, which generally has sufficient corrosion resistance and is suitable for indoor use. Typical applications include washing machine rollers, internal panels, etc. Typical 430 is often used as an alternative to 304 for kitchen appliances, dishwashers, POTS and pans, etc.

Class 3 - Chromium content: 14%-18%, containing stable elements such as titanium and niobium. Typical grades are 430Ti, 439, 441, etc.

Compared with the model, this type of grade has good weldability and formability. In most cases, its performance is even better than 304. Typical uses include sinks, heat exchange pipes (sugar industry, energy, etc.), automotive exhaust systems (which last longer than 409), and welded parts for washing machines. For applications with higher performance requirements, Category 3 grades can even replace 304.

Class 4 - Molybdenum content above 0.5%. Typical grades include 434, 436, and 444.

This type of grade increases corrosion resistance by adding molybdenum. Its typical application areas are hot water tanks, solar water heaters, automotive exhaust systems, electric heating kettles and microwave oven parts, automotive decorative strips and outdoor panels. The corrosion resistance of 444 stainless steel is comparable to 316 stainless steel.

Class 5 - Chromium content: 18%-30% Typical grades include 446, 445/447, etc.

These grades improve corrosion resistance and oxidation resistance by adding more chromium and containing molybdenum. The corrosion and oxidation resistance of this grade is superior to 316 typical use in coastal and other high corrosion resistant environments. JI S447's corrosion resistance is comparable to that of titanium.