434 STAINLESS STEEL – PRODUCT INFORMATION

1. Overview

434 stainless steel (UNS S43400) is a ferritic, molybdenum-enhanced modification of Type 430 stainless steel. It offers improved corrosion resistance, formability, and stress corrosion cracking resistance compared to 430, making it ideal for automotive trim, appliances, and industrial components exposed to mildly corrosive environments.

2. Key Properties

3. Corrosion Resistance

• Superior to 430 SS due to molybdenum addition, enhancing resistance to pitting and crevice corrosion.

• Resists organic acids, nitric acid, and atmospheric corrosion.

• Not recommended for marine/chloride-rich environments (e.g., coastal areas, de-icing salts).

• Avoid prolonged exposure to >400°C (750°F) to prevent embrittlement.

4. Fabrication & Processing

• Machining: Improved machinability vs. austenitic grades (e.g., 304) due to ferritic structure. Use carbide tools with positive rake angles.

• Forming: Excellent ductility; suitable for deep drawing, bending, and stamping. Anneal at 815–900°C (1500–1650°F) to restore formability after cold working.

• Welding: Weldable via TIG, MIG, and resistance methods. Preheating (150–200°C) and post-weld annealing recommended to retain corrosion resistance.

• Surface Finishes: Compatible with polishing, brushing, bead blasting, and coatings (e.g., PVD). Common finishes: #2B, BA, No. 4.

5. Heat Treatment

• Annealing: Heat to 760–900°C (1400–1650°F), air cool or furnace cool.

• Stress Relieving: 650–760°C (1200–1400°F), slow cool.

• Not hardenable by heat treatment (ferritic structure).

6. Applications

• Automotive: Trim, wheel covers, exhaust components (non-structural).

• Appliances: Dishwasher liners, oven cavities, washer drums.

• Industrial: Fasteners, conveyor parts, agricultural equipment.

• Consumer Goods: Cookware, sink components, architectural trim.

7. Advantages vs. 430 Stainless Steel

• 30–50% better corrosion resistance in acidic/industrial atmospheres.

• Reduced risk of intergranular corrosion (lower carbon content).

• Better resistance to stress corrosion cracking (SCC).

8. Limitations

• Lower toughness than austenitic grades (avoid sub-zero applications).

• Susceptible to embrittlement at 475°C (885°F).

• Not suitable for high-strength structural applications.

9. Equivalent Grades

10. Why Choose 434 Stainless Steel?

• Cost-effective alternative to 316 SS for mild-corrosion applications.

• Combines weldability, formability, and enhanced durability vs. 430 SS.

• Low lifecycle cost due to minimal maintenance requirements.