400 Series Stainless Steel

The 400 series group of stainless steels has an 11 percent chromium and 1-percent manganese increase, above the 300 series group. The 400 series is susceptible to rust and corrosion under some conditions. Heat-treating will harden the 400 series. The 400 series of stainless steels have higher carbon content, giving it a martensitic crystalline structure. This provides high strength and high wear resistance. Martensitic stainless steels aren’t as corrosion resistant as the austenitic types.

Yaang Stainless stocks the following products in 400 Series stainless steel:

Stainless Steel 400 Series Products
Super Duplex Stainless Steel Flanges	Duplex S31803 F51 flange,Duplex Steel S31803 SO Flange,NSI ASME JIS DIN super duplex stainless steel flanges,etc.	More Information
Stainless Steel Flanges	Stainless Steel Welding Neck Flange (WN),316L Stainless Steel Flange,317 Stainless Steel Flange,347 Stainless Steel Flange,etc.	More Information
Stainless Steel Pipe Fittings	DUPLEX S32750 (SAF 2507) Pipe Elbow,904L Pipe SR/LR Elbow,Stainless Steel 304 Elbow,347H PIPE FITTING,etc.	More Information
Stainless Steel Pipes	304L 316L Large Diameter Stainless Steel Seamless Pipes,316L/321/304 Cold Drawn Seamless Tube GOST 9941-91,ASTM A269 STPG42 G3456 SCH4O Seamless Stainless Steel Pipes AP/BA Welded Cold Drawn Pipe	More Information
Gaskets	Serrated gasket with outer ring SS316,Spiral serrated metal gasket,Basic type serrated gasket,etc.	More Information

Please contact us directly with technical questions .

he 400 series includes both ferritic and martensitic steels.

Ferritic steels: non-hardening steels,  ideal for conditions in elevated temperatures. Typical applications for ferritic stainless steels include petrochemical, automotive exhaust systems, heat exchanges, furnaces, appliances and food equipment to name a few.

Martensitic steels: able to be hardened, ideal for a wide variety of common uses. Martensitic stainless steels are used extensively in cutlery, sport knives and multi-purpose tools.

 

The table below shows common types of 400 series steel:

400 Series Applications
Type 405	a ferritic steel, used especially for welding applications
Type 408	heat-resistant; poor corrosion resistance; 11% chromium, 8% nickel.
Type 409	cheapest type; used for automobile exhausts; ferritic (iron/chromium only).
Type 410	martensitic (high-strength iron/chromium). Wear-resistant, but less corrosion-resistant.
Type 416	easy to machine due to additional sulfur
Type 420	Cutlery Grade martensitic; Excellent polishability.
Type 430	decorative steel, used for automotive trim; ferritic. Good formability, but with reduced temperature and corrosion resistance.
Type 440	a higher grade of cutlery steel, with more carbon in it, which allows for much better edge retention when the steel is heat-treated properly.
Type 446	For elevated temperature service

Advantages and Characteristics of 400 Series Stainless Steel

Ferritic, or nonhardenable stainless steels, are classified in the 400 series. This series is known for:

•  superior corrosion resistance
• resistance to scaling at elevated temperatures
• inherent strength greater than carbon steels
• provide an advantage in many applications where thinner materials and reduced weight are necessary
• nonhardenable by heat treating
• always magnetic

Martensitic, or hardenable stainless steels, are classified in the 400 series. This series is known for:

• higher levels of carbon than ferritics
• ability to be heat treated to a wide range of hardness and strength levels
• excellent corrosion resistance
•  easily machined
• good ductility

Next: Stainless Steel 403 (UNS S40300)
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