What are the application of 1.4003 stainless steel?

Apr 02, 2026

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1.4003 stainless steel, commonly known as 3Cr12 or UNS S40977, is a lean duplex stainless steel that combines the good corrosion resistance of stainless steel with the strength and cost-effectiveness of structural steel. With its balanced ferritic-austenitic microstructure and low nickel content, it offers approximately twice the yield strength of standard 304 stainless steel while providing good weldability, excellent fatigue resistance, and superior abrasion resistance. This makes it an ideal choice for structural applications, mining equipment, and transportation industries where high strength and moderate corrosion resistance are required.

Standard	Equivalent Grade
EN (Europe)	1.4003
ASTM/AISI (USA)	3Cr12, UNS S40977
Common Name	3Cr12

Element	C	Si	Mn	P	S	Cr	Ni	N
Content (%)	≤ 0.03	≤ 1.0	≤ 1.5	≤ 0.04	≤ 0.015	10.5 - 12.5	0.5 - 1.5	≤ 0.03

Property	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HB)
Typical Value	≥ 350 MPa	450 - 650 MPa	≥ 20%	≤ 200

High Strength: Offers approximately twice the yield strength of 304 stainless steel (350 MPa vs. 200 MPa), allowing for weight reduction and thinner sections in structural applications.

Good Corrosion Resistance: Provides corrosion resistance similar to 304 in many environments, particularly against atmospheric corrosion, mild chemicals, and exhaust gases.

Excellent Abrasion and Erosion Resistance: The duplex structure provides good resistance to wear and erosion, making it suitable for material handling applications.

Good Weldability and Formability: Can be welded using common techniques without preheating, and exhibits good formability for bending and fabrication.

Structural Engineering: Bridges, walkways, handrails, and structural components requiring high strength.

Transportation: Railway wagons, truck trailers, shipping containers, and vehicle frames.

Mining and Material Handling: Chutes, hoppers, screens, conveyors, and processing equipment.

Storage Tanks: Tanks for bulk solids, water, and mild chemicals.

Architectural: Building cladding, roofing, and structural supports.

Food Processing: Equipment handling dry foods and mild processing environments.

3Cr12 offers significantly higher yield strength than both 304 and 410, with approximately twice the yield strength of 304. It provides corrosion resistance comparable to 304 in many environments, particularly for atmospheric exposure and mild chemical service. Unlike 410, which is martensitic and requires post-weld heat treatment, 3Cr12 has excellent weldability. It is more cost-effective than 304 due to its lower nickel and chromium content, making it an economical alternative for applications where the highest corrosion resistance is not required. 3Cr12 is magnetic, while 304 is non-magnetic.

3Cr12 has excellent weldability using all common methods including TIG, MIG, SMAW, and SAW. Key considerations include:

No preheating is required for most thicknesses

Matching filler metals are available, though austenitic fillers (309L) may be used for improved ductility

Low heat input techniques are recommended to maintain the duplex structure

Interpass temperature should be kept below 200°C

Post-weld heat treatment is not required for most applications

Good resistance to hydrogen-induced cracking

Suitable for welding in all positions

3Cr12 is suitable for service from cryogenic temperatures up to approximately 300°C (570°F). It maintains good toughness at low temperatures and good strength at elevated temperatures within this range. For applications requiring higher temperature capability, grades with higher chromium content may be more suitable. The material exhibits good resistance to scaling up to about 700°C, but mechanical properties begin to degrade above 300°C.

GNEE Steel supplies cost-effective 3Cr12 (1.4003) stainless steel in plate, sheet, bar, and structural profiles for demanding structural and industrial applications. We provide full material certification (EN 10204 3.1) and processing support including cutting, bending, forming, and welding services. If you have any requirements, please feel free to contact us.