DX2205

Duplex Stainless Steel Plate DX2205 Manusteelcn Origin

Chemical Composition

Typical values- PREN = 35

⁽¹⁾According to EN10088-2.

This grade complies with:

• Stainless Europe Material Safety Data Sheet n°1 (European Directive 2001/58/EC).
• European directive 2000/53/EC on end-of-life vehicles and later modifications.
• NFA 36 711 standard “Stainless Steel intended for use in contact with foodstuffs, products and beverages for human and animal consumption (non packaging steel).”

General Characteristics

The principal features of DX2205 are:

• AN excellent corrosion resistance, with a minimum PREN value of 35
• Twice as high yield strength as our grade 18-9 E (1.4301, Type 304)
• Service temperature range: -40°C to 300°C

Applications

• Equipment and piping for the chemical industry, oil and gas industries and desalination plants
• Heat exchangers

Products range

Forms: sheet, blank, coil, strip, tube

Thicknesses: 0.6 – 9 mm ( >9 mm on demand)

Width: up to 2000 mm (depends on thickness)

Finishes: hot rolled, cold rolled

Metallurgical properties

The grade DX2205 is a stainless steel of the austenitic-ferritic group, whose structure is composed of a mix of ferritic (α) and austenitic (γ) phases. The dual phase structure of the alloy makes it possible to obtain elevated yield strength values whilst still maintaining sufficient ductility. The hardening is indeed provided by the ferritic phase, whereas the austenitic lattice enables to preserve both ductility and toughness.

The mixed structure confers a good resistance to stress corrosion cracking to grade DX2205 and also makes it insensitive to intergranular corrosion.

Its high chromium and molybdenum content makes it resistant against both pitting and uniform corrosion.

Microstructure of DX2205 (dark areas represent the ferritic phase)

Continuous use of DX2205 at temperatures above 300°C is not recommended for the following reasons:

• between 350 and 550°C: loss of ductility by embrittlement of the ferritic phase due to the formation of a so-called α’ phase, possibly accompanied by other embrittling phases; this is a classical phenomenon encountered with ferritic stainless steels, more commonly referred to as “475 °C embrittlement”.
• between 600 and 950 °C: embrittling sigma phase precipitation, related to the high chromium and molybdenum content.

Physical Properties

Cold rolled and annealed sheet.

Density	ρ	kg/dm3	20°C	7.8
Melting temperature			°C	1460
Specific heat	c	J/kg.K	20°C	460
Thermal conductivity	k	W/m.K	20°C	16
Mean coefficient of thermal expansion*	α	10-6/K	20-100°C 20-200°C	13.0 13.5
Electric resistivity	ρ	Ω.mm2/m	20°C	0.8
Magnetic				yes
Young's modulus	E	Mpa.103	20°C	y200es

*Thermal expansion 25% lower than that of 316, comparable with carbon steel

Mechanical properties

In annealed condition

According EN 1002-1 (July 201), test piece perpendicular to rolling direction.

Test piece:

Length=80 mm ( thickness < 3 mm).

Length= 5,65 √So ( thickness ≥ 3 mm).

Corrosion resistance

This grade is particularly recommended under severe corrosion conditions, where it can replace highly alloyed austenitic stainless steels.

Uniform corrosion

Resistance of DX2205 according to chloride and fluoride content and pH                           Limiting service conditions of DX2205 in sulphuric acid(maximum corrosion rate= 0,2 mm/year)