Stainless Steel Grade EN 1.4362 | S32304 (2304)

EN 1.4362 | X2CrNiN23-4 is a low-carbon and high-alloy stainless steel with a nickel content of less than 4%. The steel has a ferritic-austenitic structure, so it is called duplex stainless steel. In general, the two-phase stainless steel alloy element has a good balance.

It contains ferritic elements such as chromium and molybdenum and contains austenitic elements nickel and manganese.

EN 1.4362 has excellent corrosion resistance in acidic environments, especially phosphoric and organic acids. It also demonstrates good corrosion resistance in environments with a low chloride content. The steel has a higher corrosion resistance compared to AISI 316L. Due to its two-phase structure, the steel is significantly superior to austenitic grades, since it is insensitive to intercrystalline corrosion. It is particularly resistant to stress corrosion cracking.

Welding

Steel EN 1.4362 (DUPLEX) is easily welded using all welding methods, both with and without fillers. Use a suitable filler if necessary. No heat treatment is required after welding. Due to its two-phase structure, the material exhibits low susceptibility to thermal cracking. Welding parameters should be optimally selected for the controlled ferrite content. It is recommended to use higher energy (10 - 25 kJ/mm) for welding, as this leads to a better distribution of phases in the weld zone. The maximum interval temperature should be 150 °C.

Forging

EN 1.4362 | S32304 (2304) | X2CrNiN23-4 is sensitive to thermal shock. Therefore, a slow heating to 1150 °C is necessary to ensure forging in the temperature range 1150 °C - 900 °C. Further cooling must be carried out very quickly in air.

Mechanical processing

Like other duplex steels, EN 1.4362 can be machined, but with some difficulties. This is due to its two-phase microstructure and the associated strength properties. The ideal cutting conditions are more limited than for austenites (austenitic stainless steels). Whenever possible, it is always recommended to use coated carbide inserts or cermets.

Physical properties

Table No. 1: Physical properties of stainless steel grade EN 1.4362 | S32304 (2304) | X2CrNiN23-4
Density g/cm³	7,8
*Specific heat capacity at +20°C, J/kgK**	500
*Thermal conductivity at +20°C, W/mK**	15
*Specific electrical resistance at +20°C, μOhmm**	0,78
Magnetic properties	magnetic

Table No. 2: Physical properties of stainless steel grade EN 1.4362 | S32304 (2304) | X2CrNiN23-4
Temperature	+20°С	+100°С	+200°C	+300°С
Modulus of elasticity, GPa	200	194	186	180
Coefficient of linear expansion, 10^-6/°C	13,0	13,0	13,5	14,0

Table: chemical composition of steel grade EN 1.4362 | S32304 (2304) | X2CrNiN23-4
Chemical composition of steel grade EN 1.4362 \| S32304 (2304) \| X2CrNiN23-4
C	Si	Mn	P	S	Cr	Ni	Mo	Cu	N	Fe
<0,03	<1,00	<2,0	<0,035	<0,015	22,0-24,5	3,5-5,5,9	0,10-0,60	0,10-0,60	0,05-0,20	Other

To a limited extent, this grade can be used as a low-cost substitute for austenitic chromium-nickel or chromium-nickel-molybdenum steels, possibly also for EN 1.4460. It has a much higher yield than austenitic steels. DUPLEX S32304 (2304) | X2CrNiN23-4 stainless steel has become popular due to its unique combination of corrosion resistance, resistance to stress corrosion cracking and high tensile strength and yield strength. Its high strength makes this steel ideal for the construction industry. With a relatively low nickel content compared to conventional austenites, EN 1.4362 is also attractive in terms of cost.