SS409 stainless steel

Introduction

We manufacture sheets, coils, and plates in stainless steel specifically for SS409, designed for high-temperature and corrosion-resistant applications.

SS409 is a low-chromium, low-nickel ferritic stainless steel with excellent resistance to oxidation and corrosion at elevated temperatures. It is commonly used in automotive exhaust systems, heat exchangers, and other environments where good heat resistance and moderate corrosion resistance are required.

This grade offers good formability, weldability, and cost-effectiveness compared to higher alloyed stainless steels.

Chemical composition

Element Content (%) Function / effect
Carbon (c) Max 0.03 Low carbon to reduce carbide precipitation
Chromium (cr) 10.5 – 11.75 Provides corrosion and oxidation resistance
Nickel (ni) Max 0.75 Low nickel content to improve cost effectiveness
Manganese (mn) Max 1.00 Improves strength and hardenability
Silicon (si) Max 1.00 Improves oxidation resistance
Phosphorus (p) Max 0.040 Controlled to improve toughness
Sulphur (s) Max 0.030 Controlled for better machinability

Mechanical properties

  • Tensile strength: 450 – 550 MPa
  • Yield strength: 275 – 380 MPa
  • Elongation: 20 – 30 %
  • Hardness: 130 – 160 HB

Heat treatment

  • Annealing: improves ductility and relieves internal stresses
  • No hardening by heat treatment, ferritic structure maintained
  • Solution annealing for stress relief if required

Key features and benefits

  • Excellent resistance to oxidation and high temperature corrosion
  • Good formability and weldability
  • Cost-effective alternative to higher alloyed stainless steels
  • Stable ferritic microstructure providing good dimensional stability
  • Suitable for automotive exhaust systems and industrial applications

Typical applications

  • Automotive exhaust system components
  • Heat exchangers
  • Furnace parts
  • Industrial equipment exposed to moderate corrosive environments
  • Decorative applications where high temperature resistance is needed

Equivalent steel grades

  • Astm a240 type 409
  • Jis sus 409
  • En 1.4512

Why Choose SS409 For Your Application?

SS409 Is An Ideal Choice For Applications Requiring Resistance To Oxidation And Moderate Corrosion At An Economical Cost. Its Excellent Weldability And Resistance To Thermal Fatigue Make It Particularly Suitable For Automotive And Exhaust Applications. While It Does Not Offer The Corrosion Resistance Of Austenitic Grades, It Provides Sufficient Performance For Many Industrial Uses At A Lower Cost.

Comparison table for similar grades

Grade Chromium (%) Nickel (%) Key applications Comments
SS409 10.5 – 11.75 Max 0.75 Exhaust systems, heat resistance Low nickel, cost-effective ferritic ss
Ss430 16 – 18 Max 0.75 General purpose ferritic ss Higher chromium, better corrosion resistance
Ss405 11 – 13 Max 0.75 High temp and corrosion Similar to SS409, slightly different composition

Summary

SS409 is a low-alloy ferritic stainless steel that provides excellent high-temperature corrosion and oxidation resistance at a lower cost than higher alloyed stainless steels. It is ideal for automotive exhaust systems and industrial applications where good formability, weldability, and long service life are required.