Stainless Steel Grade AISI 318 | EN 1.4462

AISI 318 | EN 1.4462 | X2CrNiMoN22-5-3 belongs to the family of duplex stainless steels. It is characterized by an excellent combination of corrosion resistance and strength. The strength is approximately 2 times greater than that of austenitic grades such as AISI 316L. The steel is ideal for the construction industry.

The use of EN 1.4462 duplex stainless steel is becoming popular due to its unique combination of excellent corrosion resistance, resistance to stress corrosion cracking, high tensile strength and yield strength. The relatively lower nickel content compared to conventional austenitic grades makes this steel a very interesting alternative from an economic point of view.

This grade has excellent corrosion resistance in chloride and acidic environments, especially phosphoric and organic acids. The corrosion resistance is higher than that of EN 1.4404. As a result of the duplex structure, AISI 318 | EN 1.4462 | X2CrNiMoN22-5-3 exhibits excellent corrosion resistance compared to austenitic grades, since it is not susceptible to intergranular corrosion and also because this class of steel is extremely resistant to stress corrosion cracking. This stainless steel is also resistant to pitting corrosion, which, together with its resistance to stress corrosion cracking, explains its widespread use in the marine industry.

Welding

As with all duplex stainless steels, care should be taken when welding EN 1.4462. The optimum bending parameters of the welding are small and deviations outside these optimum limits can result in poor welding. Under the specified welding parameters, weldability is good. Using slightly higher thermal inputs is better, as this leads to a better distribution of the phases in the weld zone, which in turn leads to improved mechanical properties of the weld.

Forging

Care should be taken during forging as this alloy is susceptible to impact loading problems at elevated temperatures. Gradual heating to 1200 °C is recommended so that forging occurs at temperatures between 1200 °C and 900 °C. Air cooling should be performed after forging.

Mechanical processing

Like all duplex stainless steels, EN 1.4462 is somewhat difficult to machine. The factors responsible for this include the high strength and the duplex structure. The optimum machining parameters lie in a narrower band than for austenitic stainless steel grades. For machining EN 1.4462 | X2CrNiMoN22-5-3, it is recommended to use metal-coated cutting/machining tools or the use of cermets.

Physical properties

Table No. 1: Physical properties of stainless steel grade AISI 318 | EN 1.4462 | X2CrNiMoN22-5-3
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**	0,8
Magnetic properties	magnetic

Table No. 2: physical properties of stainless steel grade AISI 318 | EN 1.4462 | X2CrNiMoN22-5-3
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 AISI 318 | EN 1.4462 | X2CrNiMoN22-5-3
Chemical composition of steel grade AISI 318 \| EN 1.4462 \| X2CrNiMoN22-5-3
C	Si	Mn	P	S	Cr	Ni	Mo	N	Fe
<0,030	<1,00	<2,0	<0,035	<0,015	21,0-23,5	4,5-6,5	2,5-3,5	0,10-0,22	Other

Stainless steel grade AISI 318 | EN 1.4462 | X2CrNiMoN22-5-3 is one of the most popular duplex (austenitic-ferritic) steels in the world. This steel combines many remarkable properties that are so appreciated by consumers.