The typical chemical composition for this grade is given in the table below, together with composition limits given for this grade according to different standards. The required standard will be fully met as specified on the order.The relatively low Ni and Mo content of Outokumpu LDX 2404^® make this grade more price stable compared to common standard stainless steel grades.

The duplex stainless steels have much higher mechanical strength compared to standard stainless steels. If the high strength of the duplex grades can be utilised, down gauging can be done in many applications leading to cost efficient solutions. The allowable design values may vary between product forms. The appropriate values are given in the relevant specifications.Outokumpu LDX 2404^® is not yet listed in EN 10088. The data given for LDX 2404^® corresponds to the internal standard AM 641.

The product types  P= hot rolled plate, H=hot rolled strip and C=cold rolled coil and strip.

¹⁾Elongation according to EN standard:
A₈₀ for thickness below 3 mm.
A for thickness = 3 mm.
Elongation according to ASTM standard A_2” or A₅₀.

The corrosion resistance of LDX 2404^® is better than for Cr-Ni-Mo grades such as 4404 and duplex grades suchas 2304. The grade is suitable for use in a wide range of applications and environments.
The resistance to pitting and crevice corrosion is particularly important in chloride-containing environments. The resistance of LDX 2404^® to these types of corrosion is good, due to the high chromium and nitrogen content of this gradeand further improved by the addition of molybdenum.

PRE Pitting Resistant Equivalent calculated using the formula: PRE = %Cr + 3.3 x %Mo + 16 x %N
CPT Corrosion Pitting Temperature as measured in the Avesta Cell (ASTM G 150), in a 1M NaCl solution (35,000 ppm or mg/l chloride ions).
CCT Critical Crevice Corrosion Temperature is the critical crevice corrosion temperature which is obtained by laboratory tests according to ASTM G 48 Method F

The physical properties at room temperature are shown in the table below. Data according to EN10088 or EN10095.
LDX 2404^® is not yet included in the standards, values according to internal specification.

Duplex stainless steel is suitable for all forming processes available for stainless steel. The high proof strength compared to austenitic and ferritics stainless steel can impose some differences in forming behaviour depending on chosen forming technique, such as an increased tendency to springback. This point is particularly relevant to forming of any high strength steel. If the forming process is not already decided, it is certainly possible to choose the most suitable one for duplex grades. Moreover, an excellent interplay between high proof strength, work hardening rate and elongation promote the duplex grades for light weight and cost-efficient applications with complex shapes. The impact of the high strength varies for different forming techniques. Common for all is that the estimated forming forces will be higher than for the corresponding austenitic and ferritic stainless steel grades. This effect will usually be lower than expected from just the increase in strength since the choice of duplex stainless steel is often associated with down gauging. It is important to consider that duplex stainless steel may also be more demanding for the tool materials and the lubricant. Also in this case attention should be given to the down gauging.

MachiningDuplex steels are generally more demanding to machine than conventional austenitic stainless steel such as 4404, due to the higher hardness. The machinability can be illustrated by a machinability index, as illustrated in below figure. This index, which increases with improved machinability, is based on a combination of test data from several different machining operations. It provides a good description of machinability in relation to 4404. More information can be found in the machining guidelines which are available for each duplex grade.
 WeldingDuplex steels generally have good weldability and can be welded using most of the welding methods used for austenitic stainless steel:

• Shielded metal arc welding (SMAW)
• Gas tungsten arc welding  TIG(GTAW)
• Gas metal arc welding MIG (GMAW)
• Flux-cored arc welding (FCW)
• Plasma arc welding (PAW)
• Submerged arc welding (SAW)
• Laser welding
• Resistance welding
• High frequence welding

Outokumpu produce and certify materials to most international and national standards. Work is continuously on-going to get the different grades approved for relevant standards.