Stainless Steel Grade AISI 431 | EN 1.4057 | DIN X17CrNi16-2

AISI 431 | EN 1.4057 | DIN X17CrNi16-2 is a rust- and acid-resistant martensitic chromium steel with the addition of nickel. The formation of chromium carbides and associated chromium-depleted areas makes this grade susceptible to intercrystalline corrosion. It cannot be cold worked because the grade has a high yield strength.

EN 1.4057 is a heat-treatable type of stainless steel with good corrosion resistance, torque, high strength and tensile strength. It does not lose its initial characteristics under intensive heating for a long time.

The formation of chromium carbides and the associated chromium areas that form around these precipitates make this class of steel susceptible to intergranular corrosion. Surface condition plays an important role in the corrosion resistance of this steel, with polished surfaces having much higher corrosion resistance than rougher surfaces on the same material.

Welding 

The material to be welded, with an appropriate filler, is usually heated to between 100 °C and 300 °C before welding and quenched as quickly as possible after welding to restore some ductility to the weld zone. For optimum properties, all material being processed should be re-heat treated. Care should be taken to ensure that nitrogen or carbon-containing gases are not used for the shielding gas, as this may adversely affect the weld properties. Any spatter or heat tint should be removed to ensure adequate corrosion resistance of the weld.

Forging

Care should be taken when forging materials made from this grade of stainless steel. Gradual heating to a temperature of about 850 °C before more rapid heating to a temperature of 1150 °C to 1180 °C is recommended. Forging between 1180 °C - 950 °C should then be done slowly in a furnace, dry ash or similar material to facilitate slow cooling.

Processing

The processing of stainless steel grade AISI 431 | EN 1.4057 is directly related to its hardness. And the processing process itself has similar features to the processing of carbon steels of the same hardness. Although it is clear that the processing parameters will vary depending on the structure / hardness of the specific stainless steel sample being processed.

Mechanical properties

Physical properties

Applications

The main application area of ​​this stainless steel is mechanical engineering, oil and petrochemical industries. It is used in the construction of power plants, in the automobile industry and aviation. It is recommended for the manufacture of pump and comb shafts, nuts and bolts.