Type 409 (UNS S40920)

Description

Type 409 is a heat resisting ferritic stainless steel providing good oxidation and corrosion resistance compared to carbon steel. This titanium stabilized grade was developed for automotive exhaust systems but its good formability, weldability, and corrosion resistance has led to its use in other applications. The corrosion resistance of Type 409 is better than coated carbon steel, similar to that of Type 410 stainless steel, and less than that of Type 304/304L stainless steel. Type 409 is not suggested for cosmetic or surface critical applications as light surface rusting can form during exposure to atmospheric conditions.

Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM A240 and ASME SA240*.
Element 409
Carbon 0.03
Chromium 10.5-11.7
Nickel 0.50
Manganese 1.00
Silicon 1.00
Nitrogen 0.030
Phosphorus 0.040
Sulfur 0.020
Niobium 8 x (C+N) min / 0.15-0.50
* Maximum, unless range is indicated
Mechanical Properties
Mechanical property requirements for annealed product as specified in ASTM A240 and ASME SA240.
Property 409
Yield Strength, min. (ksi) 25
Tensile Strength, min. (ksi) 55
Elongation, min. (%) 20
Hardness, max. (Rb) 88
Physical Properties
Physical properties for Type 409 stainless steel
Property 409 Data
Density, lb/in3 0.279
Modulus of Elasticity, psi 32.0 x 106
Coefficient of Thermal Expansion, 68-212˚F, /˚F 6.5 x 10-6
Thermal Conductivity, Btu/ft hr ˚F 13.2
Specific Heat, Btu/lb ˚F 0.11
Electrical Resistivity, Microohm-in 24.8
Standards
Typical standards for Type 409 stainless steel
409
ASTM A240
ASME SA240

Data are typical, are provided for informational purposes, and should not be construed as maximum or minimum values for specification or for final design, or for a particular use or application. The data may be revised anytime without notice. We make no representation or warranty as to its accuracy and assume no duty to update. Actual data on any particular product or material may vary from those shown herein.  © 2014 RMP Inc. All rights reserved.