The typical chemical composition for this grade is given in the table below, together with composition limits given for the product according to different standards. The required standard will be fully met as specified on the order.

The chemical composition is given as % by mass.

The mechanical properties of the available products are given in the table below

The mechanical properties of the available products in soft annealed condition at room temperature are given in the table below. Moderate strengths can be reached at elevated temperatures (~550 °C/1022 °F). Temperatures for excessive scaling are close to 850 °C/1562 °F. This grade, along with other austenitic corrosion-resistant steels, exhibits very high ductility and high elongation to fracture. It is not susceptible to brittle fracture in the solution annealed condition.

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.

Core 201/4372 has excellent corrosion resistance in solutions of many halogen-free organic and inorganic compounds over a wide temperature and concentration range. It can withstand many organic and sufficiently diluted mineral acids depending on the temperature of the solution. Core 201/4372 may suffer from uniform corrosion in mineral acids and hot strong alkaline solutions.

In aqueous solutions containing halogenides, e.g. chlorides or bromides, pitting and crevice corrosion may occur depending on halogenide concentration, temperature, pH-value, concentration of oxidizing compounds and crevice geometry, if applicable. The resistance against pitting and crevice corrosion of Core 201/4372 is, however, slightly lower than that of the basic austenitic CrNi standard grades. For short periods, for instance when cooking in stainless steel dishes, Core 201/4372 can tolerate even relatively high chloride concentrations. The presence of corrosion inhibiting or accelerating compounds like transition metal ions or organic compounds may influence the corrosion behavior of Core 201/4372.

Core 201/4372 is prone to chloride-induced stress corrosion cracking at temperatures over about 50 °C depending on the applied stress and the chloride concentration in the environment. Prior cold deformation of the structure under load increases the risk of stress corrosion cracking.

Core 201/4372 can be used for indoor and outdoor applications in rural areas and urban environments where chloride contamination is low. The best material performance is typically reached with the help of adequate design, correct post-weld treatment, and regular cleaning during use (if applicable).

For more information on corrosion resistance, please refer to the Outokumpu Corrosion Handbook or contact our corrosion experts.

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 of the available products are given in the table below

The crystal structure is austenitic, and therefore the material is non-magnetic in the soft annealed condition. The crystal structure becomes slightly magnetic when deformed.

*) Austenitic stainless steel grades may be magnetizable to a certain degree after cold deformation, e.g. in temper rolled condition.

Formability

Formability is good, but the forces needed and the elastic return is bigger compared to carbon steels and grade 1.4301 / AISI 304. Core 201/4372 is suitable for demanding forming operations as well as bending, and drawing due to its high elongation to fracture. Work hardening is pronounced. Sensitivity to delayed cracking after demanding forming processes may be observed, e.g. when deep drawing ratio is close to 2.0 and residual tensile stresses are present. Typically Mn-alloyed grades have a slightly lower surface reflectivity compared to the CrNi-grade 4301. This can lead to the need for increased material removal in further polishing and brushing processes.

Welding

Core 201/4372 has excellent weldability and is suitable for the full range of conventional welding methods (like MMA, MIG, MAG, TIG, SAW, LBW, or RSW), except gas welding.

Core 201/4372 has about 50% higher thermal expansion and lower heat conductivity compared to carbon steels. This means that larger deformation and higher shrinkage stresses may result from welding. In thin sections, autogenous welding may be used. In thicker section, low carbon containing Core 201/4372 is recommended. To ensure that the weld metal properties (e.g. strength and corrosion resistance) are equivalent to those of the parent metal, matching or slightly overalloyed fillers should preferably be used. The recommended filler metals are 19 9 L, 18 8 Mn, or 23 12 L.

Post-weld heat treatment is generally not required. In special cases with high risks of stress corrosion cracking or fatigue, stress relief treatment may be considered.

In order to fully restore the corrosion resistance of the weld seam, the weld discoloration should be removed by pickling and passivation.

More detailed information concerning welding procedures can be obtained from the Outokumpu Welding Handbook, available from our sales offices.

The most commonly used international product standards are given in the table below.