Fracture toughness of the lean duplex stainless steel LDX 2101

Abstract

Fracture toughness testing was performed on the recently developed lean duplex stainless steel LDX 2101 (EN 1.4162, UNS S32101). The results were evaluated by master curve analysis, including deriving a reference temperature. The master curve approach, originally developed for ferritic steels, has been used successfully. The reference temperature corresponds to a fracture toughness of 100 MPa ffiffiffiffi m p , which characterizes the onset of cleavage cracking at elastic or elastic-plastic instabilities. The reference temperature, T 0 , was À112°C and À92°C for the base and weld materials, respectively. In addition, the fracture toughness is compared with impact toughness results. Complementary crack tip opening displacements (CTODs) have also been calculated. The toughness properties found in traditional duplex stainless steels (DSS) are generally good. The current study verifies a high fracture toughness for both base and weld materials and for the low alloyed grade LDX 2101. Even though the fracture toughness was somewhat lower than for duplex stainless steel 2205, it is still sufficiently high for most low-temperature applications.

Testing and numerical modelling of lean duplex stainless steel hollow section columns

“…The reported material parameters are the Young's modulus E, the 0.2% and 1% proof stresses σ 0.2 and σ 1.0 , respectively, the ultimate tensile stress σ u , the plastic strain at fracture ε f (based on elongation over the standard gauge length A 65 . 5 , where A is the cross-sectional area of the coupon), and the strain hardening exponents n and n ' 0.2,1.0 used in the compound Ramberg-Osgood material model [10][11][12][13], which is a two-stage version of the basic Ramberg-Osgood model [14,15]. The key minimum specified material properties for grade EN 1.4162 stainless steel cold-rolled strip, as defined in [16], and included in EN 10088-4 [2], are as follows: σ 0.2 =530 N/mm 2 , σ u =700-900 N/mm 2 , ε f =30% (over a gauge length A 65 .…”

“…Within construction, although austenitic stainless steels are the most widely specified, their strengths are often not fully utilised; a recently developed 'lean duplex' stainless steel, containing approximately 1.5% nickel, may offer a more appropriate balance of properties for structural applications. The particular grade considered in this study is EN 1.4162, which is generally less expensive and possesses higher strength than the familiar austenitics, while still retaining good corrosion resistance and high temperature properties [3], together with adequate weldability [4] and fracture toughness [5]. Examples of the use of lean duplex stainless steel in construction have already emerged [6], including footbridges in FÖrde, Norway and Siena, Italy; the latter is shown in Fig.…”

Effects of Temperature and Strain Rate on Tensile Properties of a Lean Duplex Stainless Steel

“…The fracture toughness, 3) precipitation of nitrides with heat treatment, 4) and improvement of mechanical properties using stressinduced martensitic transformation of the γ phase 5,6) have been reported for lean duplex stainless steels. Herrera et al 5) investigated duplex stainless steel with α and γ volume fractions of 37% and 63%, respectively, from a Fe-19.9Cr-0.42Ni-0.16N-4.79Mn-0.11C-0.46Cu-0.35Si steel.…”

Cross-section stability of lean duplex stainless steel welded I-sections

“…A recently developed grade of stainless steel, known as lean duplex (EN 1.4162), has a far lower nickel content, around 1.5% [1], and hence considerably reduced cost. Despite the low nickel content, it possesses higher strength than austenitic stainless steel, along with good corrosion resistance and high temperature properties, and adequate weldability and fracture toughness [2][3][4].…”