Stainless Steel Grade 408

Introduction

Stainless steel is durable and resistant to corrosion; hence, it has become popular. Different grades of steel have distinctive characteristics. This article will discuss one such variant of stainless steel Grade 408. It will also lighten its chemical, mechanical, and physical properties. It will also include usage, welding methods, and applications of 408 stainless steel.

Grade 408 Chemical Composition

Element Percentage
Chromium (Cr) 10.5% - 12.6%
Nickel (Ni) 0.6% - 1.2%
Manganese (Mn) 1.0% max
Silicon (Si) 1.0% max
Carbon (C) 0.08% max
Sulphur (S) / Phosphorous (P) Trace, controlled

Some other alloying elements are manganese, silicon, sulphur, phosphorous, and carbon.

Grade 408 Mechanical Properties

  • Tensile Strength: 450-600 MPa
  • Yield Strength: ~ 275 MPa.
  • Elongation:~20%.
  • Hardness: 74-82 HRB.

Grade 408 Physical Properties

  • Density: 7.75 g/cm³.
  • Melting Point: ~ 1480°C (2700°F).
  • Thermal Conductivity: Thermal conductivity is lower than other stainless steel grades.
  • Specific Heat Capacity: ~ 500 J/(kg·K).

Grade 408 Stainless Steel Uses

  • Automotive Applications: SS 408 resists corrosion, and its endurance to high temperatures is remarkable. Hence, SS 408 is used to make exhaust systems and automotive parts.
  • Appliance Manufacturing: SS 408 is typical for household appliances such as ovens, refrigerators, and dishwashers.
  • Heat Exchangers: Its high corrosion resistance makes it suitable for heat exchanger applications.
  • Cookware: Because of its toughness and ability to prevent discoloration, it is used for manufacturing cooking utensils.
  • Architectural Applications: With its attractiveness, it is used for architectural structures and cladding because it doesn’t rust.

Grade 408 Stainless Steel Welding

  • Weldability: In general, grade 408 is suitable for welding.
  • Preheat and Interpass Temperature: Preheating with interpass temperatures of 149260°C (300250°F) is advisable to prevent cracking.
  • Welding Methods: Some typical welding techniques include shielded metal arc welding, gas tungsten arc welding, and gas metal arc welding.
  • Post-Weld Heat Treatment: Post-weld heat treatment is not required for SS 408.

Grade 408 Stainless Steel Applications

  • Automotive Exhaust Systems: Grade 408 has a solid ability to resist high temperatures or corroded atmospheres. Hence, it is apt for manufacturing car exhaust systems.
  • Kitchen Appliances: It is perfect for making kitchen utensils such as ovens and dishwashers.
  • Heat Exchangers: The SS 408 is corrosive, so its most appropriate use in many industries is as a heat exchanger.
  • Architectural Cladding: The reason grade 408 is so popular when it comes to architectural cladding on buildings is due to its aesthetic properties and high corrosion resistance.
  • Cookware: It is generally used to produce pots, pans, cookware, and other cooking utensils like forks, spoons, etc. because they have a longer life and resist staining.

Frequently Asked Questions

Q1. What is Grade 408 stainless steel used for?

Grade 408 stainless steel is primarily used in automotive exhaust systems, heat exchangers, household appliances such as ovens and dishwashers, cookware, and architectural cladding, owing to its high heat resistance and moderate corrosion resistance.

Q2. Is Grade 408 stainless steel corrosion resistant?

Grade 408 offers moderate corrosion resistance from its 10.5% to 12.6% chromium content. It is not as corrosion resistant as austenitic grades like 304 or 316, which is why it is better suited to high-heat environments than marine or high-chloride applications.

Q3. How does Grade 408 differ from Grade 409 stainless steel?

Grade 408 is optimized for heat resistance and is commonly used in exhaust systems and heat exchangers, while Grade 409 offers better resistance to atmospheric corrosion and is more widely used in automotive exhaust and structural exhaust components where longevity against weathering matters more than peak heat tolerance.

Q4. Can Grade 408 stainless steel be welded?

Yes. Grade 408 is generally weldable using shielded metal arc welding, gas tungsten arc welding, or gas metal arc welding. Preheating to an interpass temperature of 149-260 degrees Celsius is advisable to prevent cracking, and post-weld heat treatment is typically not required.

Q5. Why Source Grade 408 Stainless Steel from Ambica Steels

Ambica Steels has manufactured stainless steel bar and wire products since 1970, holding ISO 9001:2015, IATF 16949:2016, and EN 9100:2018 certifications. Our Maastricht, Netherlands warehouse supports fast delivery across Europe, alongside our New Delhi manufacturing base serving 75+ countries.

Conclusion

In summary, grade 408 stainless is adaptable and has many uses, ranging from car parts to home appliances. Its chemical content, mechanical features, and physical peculiarities make it a significant selection for many industries. Awareness of the characteristics of Grade 408 helps manufacturers, engineers, and consumers decide whether this material meets specific needs.