Courtesy of Outokumpu
Masonry Support Anchors
Courtesy of Modersohn/Aperam
Lean Duplex is a generic term covering a range of stainless steel grades which are designed to have corrosion resistance in the spectrum of 304 to 316 or slightly beyond but with at least twice the design strength at lower cost.
Approximate Composition – 20-24% Cr, 1.0-4.0% Ni, low Mo 0.1-0.25% plus N (Exact composition ranges vary between EN and ASTM standards).
These grades combine the following characteristics:
- Pitting and crevice corrosion resistance in range of 304 to just above 316
- Good stress corrosion cracking resistance
- Good yield strength (450 MPa minimum up to 550 MPa). 2-2.5 times design strength of 304/316
- Good impact toughness to minus 50ºC
- Good weldability. Parameters less critical than standard duplex and superduplex grades
- Cost effectiveness due to low alloy content especially Ni and Mo
- Moderate formability. Higher power required due to higher strength. Special formability grades being developed
Lean duplex grades offer a cost effective alternative to standard austenitic grades like 304/304L and 316/316L. With the higher design strength, section thickness can often be reduced leading to significant weight and cost reduction. Each grade in this category should be evaluated on its own merits.
Storage vessels, domestic hot water tanks, structural sections, lintels, reinforcing bar, bridges, building support products.