Types of Stainless Chemistry Defined

Salit Specialty Rebar is a leading supplier of cut and pre-assembled stainless steel rebar and mesh.

Types of Stainless Chemistry Defined-Austenitic, Duplex

There are two main types of stainless steel chemistries that are pervasive in the rebar industry – austenitic and duplex.

Austenitic steels are non-magnetic stainless steels that contain high levels of chromium and nickel, and low levels of carbon.

Duplex stainless steels are called “duplex” because they have a two-phase microstructure consisting of grains of ferritic and austenitic stainless steel.

Lean Duplex: Nickel and molybdenum can be expensive elements, and manufacturers have developed duplex stainless steels with less quantity, or “leaner” amounts of these elements to produce more price stable and economical products. The 2205 Duplex (UNS S31803) alloy was fairly common though its corrosion-resistive properties may be greater than what is needed for reinforcing bars embedded in concrete. As such, “lean” duplex stainless steels containing different combinations of alloying elements than those contained in 2205 have been developed and have become fairly common. The 2304 Duplex alloy (UNS S32304) is one example, where the chromium content is slightly higher (23 percent), but the nickel content is reduced (4 percent).