What is 1.4113 Stainless Steel?

1.4113 stainless steel, commonly known as 434 or UNS S43400, is a molybdenum-alloyed ferritic stainless steel that offers enhanced corrosion resistance compared to standard 430, particularly in chloride-containing environments. With its molybdenum addition and balanced chemistry, it provides a cost-effective alternative to austenitic grades for applications requiring good corrosion resistance and formability. Its combination of good ductility, enhanced pitting resistance, and moderate strength makes it widely used in automotive trim, kitchen equipment, and architectural applications where exposure to road salt, food acids, or mild chemicals is expected.

 

This molybdenum-enhanced ferritic grade is standardized under key international systems.

Standard	Equivalent Grade
EN (Europe)	1.4113
ASTM/AISI (USA)	434, UNS S43400
JIS (Japan)	SUS434
Common Name	434

Its composition includes molybdenum for enhanced chloride resistance and improved pitting resistance.

Element	C	Si	Mn	P	S	Cr	Mo
Content (%)	≤ 0.12	≤ 1.0	≤ 1.0	≤ 0.04	≤ 0.03	16.0 - 18.0	0.75 - 1.25

It offers good ductility, moderate strength, and enhanced corrosion resistance.

Property	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HB)
Typical Value	≥ 240 MPa	450 - 600 MPa	≥ 22%	≤ 200

 

Key Characteristics and Applications of 1.4113 / 434

Enhanced Chloride Resistance: The molybdenum addition (0.75-1.25%) provides significantly better resistance to pitting and crevice corrosion in chloride environments compared to standard 430, making it suitable for coastal applications and areas with road salt exposure.

Good Formability: Maintains good ductility and formability, suitable for bending, deep drawing, and complex forming operations.

Magnetic and Cost-Effective: Strongly magnetic and more economical than nickel-containing austenitic grades, offering a balance of performance and cost.

Good Oxidation Resistance: Adequate resistance to oxidation at elevated temperatures up to about 700°C, suitable for mild high-temperature applications.

 

Primary Applications:

Automotive Trim: Exterior trim, moldings, wheel covers, and decorative components requiring resistance to road salt and de-icing chemicals.

Kitchen Equipment: Sinks, countertops, and food preparation surfaces exposed to food acids, fruit juices, and cleaning agents.

Architectural Applications: Roofing, gutters, and downspouts in coastal or de-icing salt environments.

Catering Equipment: Commercial kitchen equipment and food handling systems requiring good corrosion resistance.

Heat Exchangers: Components in applications with mild chloride exposure.

Appliance Components: Parts requiring enhanced corrosion resistance in dishwasher and laundry equipment.

Solar Water Heaters: Absorber plates and collector components in areas with hard water or moderate chloride exposure.

 

How does 434 (1.4113) compare to 430 (1.4016) and 304 (1.4301)?
434 offers significantly better corrosion resistance than 430 due to its molybdenum addition, particularly in chloride-containing environments like road salt and coastal atmospheres. While 430 may show pitting and staining in these conditions, 434 provides enhanced protection, extending service life in moderate corrosive environments. Compared to 304, 434 offers similar corrosion resistance in many mild to moderate environments but is less expensive and more price-stable due to its lower nickel content (no nickel addition). However, 434 does not match 304's corrosion resistance in highly aggressive environments such as strong acids or high-chloride conditions, and is magnetic. It is often chosen as a cost-effective alternative to 304 for applications where the highest corrosion resistance is not required but where 430 is insufficient.

 

What are the welding considerations for 434?
Welding 434 can be more challenging than austenitic grades due to its ferritic structure. Key considerations include:

Low heat input welding techniques are recommended to minimize grain growth in the heat-affected zone

Preheating (150-200°C) may be beneficial for thicker sections to reduce thermal stress

Austenitic filler metals (309L or 316L) are recommended for better weld ductility and to avoid embrittlement

Post-weld annealing may be required to restore ductility for critical applications

Resistance welding is often preferred for thin gauge applications

For decorative applications, laser welding may provide minimal heat-affected zone and good surface finish

Welding should be performed in the annealed condition for optimal results

 

What temperature range is 434 suitable for?
434 is suitable for service up to approximately 700°C (1290°F) for continuous operation. It maintains good oxidation resistance within this range, making it suitable for automotive exhaust system components (mid to rear sections), heat exchangers, and other moderate-temperature applications. For applications requiring higher temperature capability, grades with higher chromium content such as 446 (1.4762) or austenitic grades like 309/310 may be more suitable. At elevated temperatures, 434 retains good strength and resists scaling, but prolonged exposure above 700°C may accelerate oxidation.

 

Looking for a Reliable Supplier of 1.4113 / 434 Stainless Steel?
GNEE Steel supplies cost-effective 434 (1.4113) stainless steel in sheet, coil, and strip forms, ideal for automotive trim, kitchen equipment, and architectural applications requiring enhanced corrosion resistance. We provide full material certification (EN 10204 3.1) and processing support including cutting, bending, deep drawing, and surface finishing services. If you have any requirements, please feel free to contact us.