What is 1.4521 stainless steel equivalent to?

What is 1.4521 stainless steel equivalent to?

1.4521 stainless steel is equivalent to AISI 444, also known as UNS S44400. It's a ferritic stainless steel with a high chromium and molybdenum content, offering good corrosion resistance, particularly in chloride-containing environments. It's also known as X2CrMoTi18-2 in the European norm.

 

Chemical composition % of steel X2CrMoTi18-2 (1.4521): EN 10088-2-2005

C	Si	Mn	P	S	Cr	Mo	N	Ti
max 0.025	max 1	max 1	max 0.04	max 0.015	17 - 20	1.8 - 2.5	max 0.03	0.15 - 0.8

 

Physical Properties

The following table shows the physical properties of grade 444 stainless steel.

Properties	Metric	Imperial
Density	7.80 g/cm3	0.282 lb/in³

 

Mechanical Properties

The mechanical properties of grade 444 stainless steel are displayed in the following table.

Properties	Metric	Imperial
Tensile strength	415 MPa	60200 psi
Yield strength (@strain 0.200%)	275 MPa	39900 psi
Elastic modulus	200 GPa	29000 ksi
Shear modulus	80-83 GPa	11600-12000 ksi
Poisson's ratio	0.27-0.30	0.27-0.30
Elongation at break	20%	20%
Hardness, Rockwell B	95	95

 

Thermal Properties

The thermal properties of grade 444 stainless steel are given in the following table.

Properties	Metric	Imperial
Thermal expansion co-efficient	10 µm/m°C	5.56 µin/in°F
Thermal conductivity	26.8 W/mK	186 BTU in/hr.ft².°F

 

Heat treatment and working
Recommended working and heat treatment parameters for 1.4521 alloy:
Forging: 1050-750 °C; Water, air or gas cooling.
Rolling: 1050-750 °C; Water, air or gas cooling.
Annealing: 750-900 °C; Air or gas cooling. Furnance cooling in special cases.

 

1.4521 vs 1.4401 stainless steel
1.4521 stainless steel (X2CrNiMo17-12-2) offers higher corrosion resistance than 1.4401 (AISI 316) due to its increased molybdenum content of 2–3% versus 2–2.5% in 1.4401. Typical mechanical properties for 1.4521 include tensile strength 500–700 MPa, yield strength 200–300 MPa, and elongation ≥40%, while 1.4401 usually has tensile strength 500–700 MPa, yield strength 210–290 MPa, and elongation 40%.
The improved corrosion resistance of 1.4521 makes it ideal for aggressive chemical environments, seawater applications, and chemical processing equipment, whereas 1.4401 is widely used for general-purpose applications with moderate corrosion exposure.