General Characteristics:

The material has a PREN value of 34 (Pitting Resistance Equivalent Number: %Cr + 3.3*%Mo + 16*%N). It is an extra low-carbon duplex stainless steel with yield strength nearly double that of austenitic stainless steels. It offers good weldability with minimal intergranular corrosion in welded conditions and shows high resistance to SCC in chloride and hydrogen sulfide environments. Additionally, it resists corrosion fatigue, pitting, crevice corrosion, and erosion-corrosion.

Machinability: Cutting procedures using high-speed steel tools are similar to those for AISI 316. When using carbide-tipped tools, cutting speeds should be 40% lower than for AISI 316 during roughing operations and 20% lower for finishing.

Fabricability: Twice the force is needed to initiate plastic deformation compared to AISI 304L and 316L, but plastic deformation proceeds as easily as in austenitic stainless steel beyond the yield strength. It can be cold bent up to 25% deformation without heat treatment. For conditions prone to SCC, annealing should follow bending. Hot bending is performed at 950-1100°C and must be followed by quench annealing. Tubes can be expanded using normal methods, but higher initial force is required, and the process should be done in one operation.

Weldability:The material welds easily using MMAW, GTAW, or GMAW techniques. Heat input should range from 0.5-2.5kJ/mm, with interpass temperatures not exceeding 150°C. Preheat or post-weld heat treatment is generally unnecessary. Typical filler metals are nickel over-alloyed, such as E2209. Welding with carbon steels, other stainless steels, and nickel alloys is straightforward.

Corrosion Resistance: The material provides superior general corrosion resistance compared to AISI 316L and 317L. Welded joints exhibit excellent performance in corrosive environments.