Ferritic stainless 439, 441, 445

A series of grades which compete with 304 or 304L in corrosion resistance. The absence of nickel produces a lower cost alternative. The ferritic structure gives excellent deep drawability and stress corrosion cracking resistance but disadvantages in welding of thick sections and stretch forming.

Equivalent EN and UNS grade designations: 1.4510, 1.4509, 1.4621, 1.4622, 1.4611, S43035, S43940, S44500

These grades combine the following characteristics:

• Good pitting corrosion resistance similar to 304
• Excellent resistance to stress corrosion cracking, better than standard austenitic grades 304 and 316
• Excellent deep drawing properties, slightly better than austenitic grades
• Reduction in ridging and roping during forming compared to unstabilised ferritic grades like 430
• Lower thermal expansion and higher thermal conductivity than austenitic grades
• Limited stretch formability compared to austenitic grades due to lower ductility
• Limit on welding to about 5 mm due to poor weld toughness from rapid grain growth
• Loss of toughness at sub-zero temperatures

Applications which illustrate these features include:
Exhaust systems, washing machine tubs, cladding, wall panels, roofing, handrails, catering equipment, water tubing, 

sugar processing, fuel cells, portable pizza ovens, lifts.

Available forms:

Hot and cold rolled stainless steel strip, coil, sheet and plate