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.

Typical mechanical properties in annealed condition at room temperature is shown below.

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.

Outokumpu grade Core 301/4310 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 301/4310 may suffer from uniform corrosion in mineral acids and hot strong alkaline solutions.

Due to its high carbon content, this product is easily sensitized for intergranular corrosion during heat treatment or welding.

In aqueous solutions containing halogenides like e.g. chlorides or bromides, pitting and crevice corrosion may occur depending on halogenide concentration, temperature, pH-value, concentration of oxidizing compounds or crevice geometry, if applicable. For a short periods of time, for instance when cooking food in stainless steel dishes, Core 301/4310 can even tolerate relatively high chloride concentrations. Due to its relatively low chromium content, the resistance of Core 301/4310 against pitting and crevice corrosion is slightly decreased compared to the basic austenitic CrNi Core 304/4301 and Core 304L/4307. The presence of corrosion inhibiting or accelerating compounds e.g. transition metal ions or organic compounds may influence the corrosion behavior of Core 301/4310.

Core 301/4310 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 301/4310 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 achieved with the help of adequate design, correct post-weld treatment, and regular cleaning during use (if applicable).

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

Data according to EN 10088 is shown in the table below.

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

Welding

As an austenitic stainless steel, Core 301/4310 has good 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 301/4310 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 grades are recommended. To ensure that the weld metal properties (such as strength and corrosion resistance) are equivalent to those of the parent metal, matching or slightly over-alloyed fillers should preferably be used. The recommended welding metal is 19 9 L. The Core 301/4310 has fairly high carbon content so chromium carbides may precipitate in the HAZ, resulting in increased risk of intergranular corrosion.

Core 301/4310 in the cold stretched condition can be welded in the same way as material in the annealed condition. As the additional strength obtained by temper rolling is lost within the weldment, the strength, including fatigue strength, is also reduced. The use of high heat input may also reduce the strength in the HAZ. Since the strength is reduced in the weld area, the location of the welds must be carefully considered at the design stage and the welds must be placed, if possible, in less stressed areas.

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.